FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION
[See section 10, Rule 13]
STATION BUILDING AUXILIARY POWER SUPPLY UNIT;
MITSUBISHI ELECTRIC CORPORATION, A CORPORATION ORGANISED
AND EXISTING UNDER THE LAWS OF JAPAN, WHOSE ADDRESS IS 7-3,
MARUNOUCHI 2-CHOME, CHIYODA-KU, TOKYO 100-8310, JAPAN
THE FOLLOWING SPECIFICATION PARTICULARLY DESCRIBES THE
INVENTION AND THE MANNER IN WHICH IT IS TO BE PERFORMED.
2
DESCRIPTION
5 Field
[0001] The present invention relates to a station
building auxiliary power supply unit that supplies electric
power to various types of loads in a station building.
10 Background
[0002] In recent years, regenerative power generated by
a regenerative brake of a train is supplied to another
train via an overhead line to be utilized as power-running
power of that train. However, when there are only a few or
15 no trains serving as loads that will consume the
regenerative power returned from a train to the overhead
line, regeneration cancellation may be caused, which will
prevent the use of a regenerative brake. Accordingly,
technology is conventionally known that converts excess
20 regenerative power, which is generated when the
regenerative power is higher than the power-running power,
into alternating current (AC) power, and supplies the AC
power to a station load via an AC system thus to provide
effective use of the excess regenerative power (see, e.g.,
25 Patent Literature 1).
Citation List
Patent Literature
[0003] Patent Literature 1: Japanese Patent Application
30 Laid-open No. 2006-062427
Summary
Technical Problem
3
[0004] A load with highly variable power consumption
installed in a station building may temporarily cause a
rapid increase in electric power required to operate the
loads in the station building. For example, in recent
5 years, multiple platform screen doors or the like are being
newly installed as a load in a station building. Platform
screen doors cause simultaneous operation of multiple
motors upon operation of the platform screen doors, thereby
temporarily causing a rapid increase in power consumption.
10 In such situation, excess of the electric power required
for operation of the loads in the station building over,
for example, the capacity of the transformer installed for
transforming high-voltage AC power supplied from an AC
system into low-voltage AC power to supply electric power
15 to the loads in the station building will result in
temporary failure in supplying sufficient electric power to
the loads in the station building. This will require
compensation for a temporary deficiency of electric power.
[0005] However, the technology of Patent Literature 1
20 utilizes excess regenerative power generated when the
amount of regenerative power exceeds the amount of powerrunning power, and may therefore fail to compensate for
electric power deficiency without excess regenerative power
during temporary deficiency of electric power required to
25 operate the loads in a station building.
[0006] The present invention has been made to solve the
issue as described above, and it is an object of the
present invention to provide a station building auxiliary
power supply unit capable of supplementing the supply of
30 electric power to the loads in a station building
regardless of availability of excess regenerative power.
Solution to Problem
4
[0007] In order to achieve the above object, a station
building auxiliary power supply unit according to the
present invention includes a first power conversion unit
that converts first electric power supplied from an
5 overhead line into second electric power usable by loads
installed in a station building, and a start-of-operation
determination unit that determines whether to cause the
first power conversion unit to operate, based on load state
information indicating an operational state of the loads.
10
Advantageous Effects of Invention
[0008] A station building auxiliary power supply unit
according to the present invention determines whether to
operate the first power conversion unit that converts first
15 electric power supplied from an overhead line into second
electric power usable by loads installed in the station
building, based on load state information indicating the
operational state of the loads, and is therefore capable of
supplementing the supply of electric power to the loads in
20 the station building regardless of availability of excess
regenerative power.
Brief Description of Drawings
[0009] FIG. 1 is a diagram illustrating an example of
25 configuration of a railway system including a station
building auxiliary power supply unit according to a first
embodiment of the present invention.
FIG. 2 is a diagram illustrating an example of
configuration of the control device of the station building
30 auxiliary power supply unit according to the first
embodiment of the present invention.
FIG. 3 is a flowchart illustrating an example of
process performed by the start-of-operation determination
5
unit of the station building auxiliary power supply unit
according to the first embodiment of the present invention.
FIG. 4 is a flowchart illustrating an example of
process performed by the voltage command value calculation
5 unit of the station building auxiliary power supply unit
according to the first embodiment of the present invention.
FIG. 5 is a flowchart illustrating an example of
process performed by the PWM signal generation unit of the
station building auxiliary power supply unit according to
10 the first embodiment of the present invention.
FIG. 6 is a diagram illustrating an example of
configuration of a railway system including a station
building auxiliary power supply unit according to a second
embodiment of the present invention.
15 FIG. 7 is a diagram illustrating an example of
configuration of the control device of the station building
auxiliary power supply unit according to the second
embodiment of the present invention.
FIG. 8 is a flowchart illustrating an example of
20 process performed by the start-of-operation determination
unit of the station building auxiliary power supply unit
according to the second embodiment of the present invention.
FIG. 9 is a flowchart illustrating an example of
process performed by the voltage command value calculation
25 unit of the station building auxiliary power supply unit
according to the second embodiment of the present invention.
FIG. 10 is a diagram illustrating an example of
configuration of a railway system including a station
building auxiliary power supply unit according to a third
30 embodiment of the present invention.
FIG. 11 is a diagram illustrating an example of
configuration of the control device of the station building
auxiliary power supply unit according to the third
6
embodiment of the present invention.
FIG. 12 is a flowchart illustrating an example of
process performed by the start-of-operation determination
unit of the station building auxiliary power supply unit
5 according to the third embodiment of the present invention.
FIG. 13 is a flowchart illustrating an example of
process performed by the start-of-operation determination
unit of the station building auxiliary power supply unit
according to the third embodiment of the present invention.
10 FIG. 14 is a flowchart illustrating an example of
process performed by the voltage command value calculation
unit of the station building auxiliary power supply unit
according to the third embodiment of the present invention.
FIG. 15 is a flowchart illustrating an example of
15 process performed by the PWM signal generation unit of the
station building auxiliary power supply unit according to
the third embodiment of the present invention.
FIG. 16 is a diagram illustrating an example of
hardware configuration for implementing the control devices
20 of the station building auxiliary power supply units
according to the first through third embodiments of the
present invention.
Description of Embodiments
25 [0010] A station building auxiliary power supply unit of
embodiments according to the present invention will be
described below with reference to the drawings.
[0011] First Embodiment.
As illustrated in FIG. 1, a station building auxiliary
30 power supply unit 2 installed in a station building 1
includes a control device 3, an inverter (first power
conversion unit) 4, a voltage sensor 5, and the like. This
station building auxiliary power supply unit 2 is
7
configured to be able to convert first electric power (e.g.,
1500 V DC) supplied from an overhead line 6 into second
electric power used by various loads 7 (7-1 to 7-n) in the
station building 1. Note that the inverter 4 of the
5 station building auxiliary power supply unit 2 does not
always perform conversion operation to convert the first
electric power into the second electric power. Instead, a
determination is made as to whether regenerative power
generated in one or more of the electric vehicles 8 in a
10 railway system will be completely consumed among the
electric vehicles 8 (that is, the amount of electric power
generated in those of the electric vehicles 8 decelerating
using a regenerative brake is less than the amount of
electric power that will be consumed by the other ones of
15 the electric vehicles 8 (i.e., electric vehicles 8 in power
running, etc.)). The inverter 4 performs conversion
operation when the regenerative power will not be consumed
completely.
[0012] The loads 7 are also supplied with electric power
20 (e.g., 210 V AC) obtained by transformation performed by a
transformer 9, of electric power (e.g., 6600 V AC)
generated in an electric power substation 100 and supplied
from an alternating current (AC) system 200. The loads 7
use the electric power supplied from the transformer 9.
25 The loads 7 are various types of electrical installations
such as, for example, lighting equipment, an air
conditioning apparatus, a display device, an elevator, an
escalator, and platform screen doors. The overhead line 6
is coupled to the electric power substation 100 to supply
30 electric power at, for example, 1500 V DC to the electric
vehicles 8 and the like. In the station building 1, an
electric power detection unit 10 is also provided for
detecting the amount of load power (hereinafter, simply
8
load power value) representing the total amount of electric
power consumed by the various loads 7 when in operation.
The present embodiment assumes that the electric power
detection unit 10 is, for example, an electric power meter,
5 and detects, as a load power value, the total amount of
electric power being consumed by all the loads 7 installed
in the station building 1.
[0013] The control device 3 of the station building
auxiliary power supply unit 2 determines, based on the
10 trolley voltage value, necessity of receiving regenerative
power generated by an electric vehicle 8 in operation via
the overhead line 6, and of converting the regenerative
power into electric power to be supplied to the loads 7,
and upon a determination that these are necessary, controls
15 the inverter 4 to perform conversion operation. The
inverter 4 includes switching devices, and turns on and off
each of the switching devices according to an instruction
from the control device 3 to convert the first electric
power supplied from the overhead line 6 into the second
20 electric power to be supplied to the loads 7. The voltage
sensor 5 measures the trolley voltage.
[0014] FIG. 2 is a diagram illustrating an example of
configuration of the control device 3 of the station
building auxiliary power supply unit 2 according to a first
25 embodiment of the present invention. The control device 3
includes an interface unit 31, a start-of-operation
determination unit 32, a memory unit 33, a voltage command
value calculation unit 34, and a pulse width modulation
(PWM) signal generation unit 35.
30 [0015] The interface unit 31 periodically (e.g., every
20 ms) obtains, for example, a trolley voltage measurement
value (hereinafter referred to as “trolley voltage value”)
output from the voltage sensor 5, and performs analog-to-
9
digital (A/D) conversion on the trolley voltage value. The
interface unit 31 also obtains load state information
indicating the operational state of the loads 7. In the
present embodiment, the interface unit 31 periodically
5 (e.g., every 20 ms) obtains, as the load state information,
for example, load power information output from the
electric power detection unit 10, indicating the load power
value that is the total amount of electric power being
consumed by the various loads 7 that are in operation. The
10 interface unit 31 then performs analog-to-digital (A/D)
conversion on the electric power value.
[0016] The start-of-operation determination unit 32
determines, based on the load state information obtained by
the interface unit 31, whether to cause the inverter 4 to
15 perform conversion operation to convert direct current (DC)
power, which is the first electric power, supplied from the
overhead line 6 into AC power, which is the second electric
power, usable by the loads 7. The start-of-operation
determination unit 32 also determines whether to cause the
20 inverter 4 to perform conversion operation based on the
trolley voltage value obtained by the interface unit 31.
When a determination has been made, for example, to cause
the inverter 4 to perform conversion operation, the startof-operation determination unit 32 generates a signal
25 representing the determination to cause the inverter 4 to
perform conversion operation, and outputs the signal to the
voltage command value calculation unit 34.
[0017] The memory unit 33 stores, for example, a first
threshold and a second threshold for use by the start-of30 operation determination unit 32 to determine whether to
cause the inverter 4 to perform power conversion operation.
The first threshold is used for comparison with the load
power value indicated in the load power information output
10
from the electric power detection unit 10. The first
threshold is preset based on, for example, the capacity of
the transformer 9 for transforming high-voltage AC power
supplied from the AC system into low-voltage AC power to
5 supply electric power to the various loads 7. The first
threshold is set to a value at least less than or equal to
the capacity of the transformer 9. The second threshold is
used for comparison with the trolley voltage value output
from the voltage sensor 5. The second threshold is a
10 threshold used as a criterion for determining whether to
cause the inverter 4 to perform conversion operation to
supply non-utilized excess regenerative power to the
various loads 7 in the station building 1 when there are
only a few or no other electric vehicles 8 serving as a
15 load that consumes regenerative power returned from an
electric vehicle 8 to the overhead line 6.
[0018] For example, in a case of reception, from the
start-of-operation determination unit 32, of the signal
representing a determination to cause the inverter 4 to
20 perform conversion operation, the voltage command value
calculation unit 34 calculates a voltage command value
dependent on that signal. The voltage command value
calculation unit 34 outputs the voltage command value
calculated to the PWM signal generation unit 35. The PWM
25 signal generation unit 35 generates a pulse width
modulation (PWM) signal for controlling the inverter 4,
based on the voltage command value input from the voltage
command value calculation unit 34.
[0019] FIG. 3 is a flowchart illustrating an example of
30 process performed by the start-of-operation determination
unit 32 of the station building auxiliary power supply unit
2 according to the first embodiment of the present
invention. An example of flow of the process performed by
11
the start-of-operation determination unit 32 of the station
building auxiliary power supply unit 2 according to the
first embodiment of the present invention will be described
below with reference to the flowchart of FIG. 3.
5 [0020] As illustrated in FIG. 3, at step S101, the
start-of-operation determination unit 32 obtains, from the
interface unit 31, information on the trolley voltage value
having been converted into a digital signal, and on the
load power value representing the sum of the amounts of
10 electric power being consumed by the various loads 7 that
are in operation. Next, at step S102, the start-ofoperation determination unit 32 determines whether the load
power value obtained at step S101 is greater than or equal
to the first threshold stored in the memory unit 33.
15 [0021] If the load power value is determined to be
greater than or equal to the first threshold (Yes) at step
S102, the start-of-operation determination unit 32
determines, at step S103, to cause the inverter 4 to
perform conversion operation. Then, at step S104, the
20 start-of-operation determination unit 32 generates a first
signal including, for example, information indicating the
determination to cause the inverter 4 to perform conversion
operation, and power deficiency information indicating the
difference between the load power value and the first
25 threshold. At step S105, the start-of-operation
determination unit 32 outputs the first signal generated,
to the voltage command value calculation unit 34.
[0022] If the load power value is determined not to be
greater than or equal to the first threshold (No) at step
30 S102, the start-of-operation determination unit 32
determines, at step S106, whether the trolley voltage value
obtained at step S101 is greater than or equal to the
second threshold stored in the memory unit 33.
12
[0023] If the trolley voltage value is determined to be
greater than or equal to the second threshold (Yes) at step
S106, the start-of-operation determination unit 32
determines, at step S107, to cause the inverter 4 to
5 perform conversion operation. Then, at step S108, the
start-of-operation determination unit 32 generates a second
signal including, for example, information indicating the
determination to cause the inverter 4 to perform conversion
operation, and excess regenerative power presence
10 information indicating that excess regenerative power is
available. At step S109, the start-of-operation
determination unit 32 outputs the second signal generated,
to the voltage command value calculation unit 34.
[0024] If the trolley voltage value is determined not to
15 be greater than or equal to the second threshold (No) at
step S106, the start-of-operation determination unit 32
determines, at step S110, whether the inverter 4 is
performing conversion operation. If the inverter 4 is
determined to be performing conversion operation (Yes) at
20 step 110, the start-of-operation determination unit 32
determines, at step S111, to stop the conversion operation
of the inverter 4. If the inverter 4 is performing
changing operation, the start-of-operation determination
unit 32 stops, at step S112, generation and outputting of
25 the first signal and the second signal.
[0025] If the inverter 4 is determined not to be
performing conversion operation (No) at step S110, the
start-of-operation determination unit 32 determines, at
step S113, not to cause the inverter 4 to perform
30 conversion operation. Note that the start-of-operation
determination unit 32 repeats the process at and after step
S102, for example, each time the trolley voltage value and
the load power value are obtained.
13
[0026] FIG. 4 is a flowchart illustrating an example of
process performed by the voltage command value calculation
unit 34 of the station building auxiliary power supply unit
2 according to the first embodiment of the present
5 invention. An example of flow of the process performed by
the voltage command value calculation unit 34 of the
station building auxiliary power supply unit 2 according to
the first embodiment of the present invention will be
described below with reference to the flowchart of FIG. 4.
10 [0027] As illustrated in FIG. 4, at step S201, the
voltage command value calculation unit 34 determines
whether the first signal has been input from the start-ofoperation determination unit 32. If the first signal is
determined to have been input (Yes) at step S201, the
15 voltage command value calculation unit 34 calculates a
voltage command value, at step S202, based on, for example,
the power deficiency information included in the first
signal, indicating the difference between the load power
value and the first threshold. That is, a voltage command
20 value is calculated taking into account the degree of power
deficiency relative to the first threshold experienced by
the whole set of the loads 7 in the station building 1.
Then, at step S203, the voltage command value calculation
unit 34 outputs the voltage command value calculated at
25 step S202, to the PWM signal generation unit 35.
[0028] Otherwise, if the first signal is determined not
to have been input (No) at step S201, the voltage command
value calculation unit 34 determines, at S204, whether the
second signal has been input from the start-of-operation
30 determination unit 32. If the second signal is determined
to have been input (Yes) at step S204, the voltage command
value calculation unit 34 understands, at S205, that excess
regenerative power is available based on the excess
14
regenerative power presence information included in the
second signal, and calculates a voltage command value based
on, for example, a preset setting value of electric power
to be consumed in the station building auxiliary power
5 supply unit 2 in presence of excess regenerative power.
Then, at step S203, the voltage command value calculation
unit 34 outputs the voltage command value calculated at
step S205, to the PWM signal generation unit 35. Otherwise,
if the second signal is determined not to have been input
10 (No) at step S204, the voltage command value calculation
unit 34 repeats the process at and after step S201.
[0029] FIG. 5 is a flowchart illustrating an example of
process performed by the PWM signal generation unit 35 of
the station building auxiliary power supply unit 2
15 according to the first embodiment of the present invention.
An example of flow of the process performed by the PWM
signal generation unit 35 of the station building auxiliary
power supply unit 2 according to the first embodiment of
the present invention will be described below with
20 reference to the flowchart of FIG. 5.
[0030] As illustrated in FIG. 5, at step S301, the PWM
signal generation unit 35 receives the voltage command
value input from the voltage command value calculation unit
34. At step S302, the PWM signal generation unit 35
25 generates a PWM signal for controlling the conversion
operation of the inverter 4 based on the voltage command
value input at step S301. Then, at step S303, the PWM
signal generation unit 35 outputs the PWM signal generated
at step S302 to the inverter 4. The inverter 4 performs
30 conversion operation based on the PWM signal input from the
PWM signal generation unit 35.
[0031] Note that the station building auxiliary power
supply unit 2 according to the first embodiment of the
15
present invention has been described using an example in
which the start-of-operation determination unit 32 compares
the load power value that is the total amount of electric
power being consumed by all the loads 7 installed in the
5 station building 1, with the first threshold to determine
whether to cause the inverter 4 to perform conversion
operation. However, the station building auxiliary power
supply unit 2 does not necessarily need to use, in the
process performed by the start-of-operation determination
10 unit 32, the load power value that is the total amount of
electric power being consumed by all the loads 7 installed
in the station building 1, but may instead use a load power
value that is the total amount of electric power being
consumed by preset particular multiple ones of the loads 7,
15 or the amount of load power being consumed by a preset
particular one of the loads 7. For example, the station
building auxiliary power supply unit 2 may be configured
such that the loads 7 other than loads 7 such as lighting
equipment and an air conditioning apparatus that are almost
20 always operating are set in advance as the particular ones
of the loads 7, and the start-of-operation determination
unit 32 compares a load power value that is the total
amount of electric power being consumed by the particular
ones of the loads 7 other than loads 7 such as lighting
25 equipment and an air conditioning apparatus, with a preset
threshold. Note that the threshold for comparison with the
load power value that is the total amount of electric power
being consumed by particular multiple ones of the loads 7,
or with the amount of load power being consumed by a
30 particular one of the loads 7 is not particularly limited,
and may be set as appropriate depending on the type(s) or
the like of the particular one(s) of the loads 7. Note
that the load power value that is the total amount of
16
electric power being consumed by particular multiple ones
of the loads 7 and the amount of load power being consumed
by a particular one of the loads 7 are both expected to be
lower than the load power value that is the total amount of
5 electric power being consumed by all the loads 7.
Accordingly, the threshold for comparison with the load
power value that is the total amount of electric power
being consumed by particular multiple ones of the loads 7
and the threshold for comparison with the amount of load
10 power being consumed by a particular one of the loads 7 are
each preferably set to a value less than the first
threshold for comparison with the load power value that is
the total amount of electric power being consumed by all
the loads 7.
15 [0032] The station building auxiliary power supply unit
2 according to the first embodiment of the present
invention has also been described using an example of
obtaining, as the load state information, load power
information output from the electric power detection unit
20 10, indicating a load power value that is the total amount
of electric power being consumed by the various loads 7
that are in operation. However, the station building
auxiliary power supply unit 2 does not necessarily need to
obtain the load power information using the electric power
25 detection unit 10, but instead, the control device 3 may
obtain, from the various loads 7, information including,
for example, start information indicating starting of each
of the loads 7 and load power information indicating the
amount of electric power required for operation of each of
30 the loads 7, as the load state information. In such case,
the start-of-operation determination unit 32 of the control
device 3, for example, sums up the load power value
indicated in the load power information included in the
17
load state information obtained from each of the various
loads 7, and compares the sum with the first threshold.
[0033] Alternatively, the station building auxiliary
power supply unit 2 may, for example, previously store, in
5 the memory unit 33, load power information indicating the
amount of load power required during operation of each of
the various loads 7, and obtain start information for
operating each of the loads 7, as the load state
information, from the various loads 7. In such case, the
10 start-of-operation determination unit 32 of the control
device 3 extracts, from the memory unit 33, the load power
information of each of the loads 7 corresponding to the
various pieces of start information obtained, sums up the
load power value indicated in each piece of the load power
15 information, and compares the sum with the first threshold.
[0034] In addition, in the station building auxiliary
power supply unit 2 according to the first embodiment of
the present invention, the start-of-operation determination
unit 32 generates a first signal including power deficiency
20 information indicating the difference from the first
threshold when the load power value is determined to be
greater than or equal to the first threshold, and outputs
the first signal to the voltage command value calculation
unit 34. Moreover, the voltage command value calculation
25 unit 34 calculates a voltage command value based on power
deficiency information difference from the first threshold
included in the first signal when the first signal has been
input from the start-of-operation determination unit 32.
However, the start-of-operation determination unit 32 does
30 not necessarily need to include the power deficiency
information indicating the difference from the first
threshold in the first signal, but may only include
information indicating the determination to cause the
18
inverter 4 to perform conversion operation in the first
signal. In such case, the voltage command value
calculation unit 34 can calculate the voltage command value
based on, for example, a preset setting value of electric
5 power to be consumed in the station building auxiliary
power supply unit 2.
[0035] The station building auxiliary power supply unit
2 according to the first embodiment of the present
invention includes the inverter 4, which is a first power
10 conversion unit that converts first electric power supplied
from the overhead line 6 into second electric power usable
by the loads 7 installed in the station building 1, and the
start-of-operation determination unit 32, which determines
whether to cause the inverter 4 to perform conversion
15 operation, based on load state information indicating the
operational state of the loads 7. Thus, the supply of
electric power to the loads 7 in the station building can
be supplemented regardless of availability of excess
regenerative power.
20 [0036] According to the station building auxiliary power
supply unit 2 according to the first embodiment of the
present invention, the load state information includes load
power information indicating the amount of load power
consumed by the loads 7, and the start-of-operation
25 determination unit 32 determines to cause the first power
conversion unit to perform conversion operation when the
amount of load power indicated in the load power
information exceeds the preset first threshold. Thus, the
supply of electric power to the loads 7 in the station
30 building 1 can be supplemented regardless of availability
of excess regenerative power when the load power value
exceeds the first threshold.
[0037] According to the station building auxiliary power
19
supply unit 2 according to the first embodiment of the
present invention, the load power information is
information indicating the total amount of load power
consumed by the multiple loads 7 installed in the station
5 building 1. Thus, the supply of electric power to the
loads 7 in the station building 1 can be supplemented
regardless of availability of excess regenerative power
when the total amount of load power consumed by the
multiple loads 7 exceeds the first threshold.
10 [0038] The station building auxiliary power supply unit
2 according to the first embodiment of the present
invention includes the voltage command value calculation
unit 34, which calculates a voltage command value based on
the difference between the amount of load power indicated
15 in the load power information and the first threshold when
the amount of load power indicated in the load power
information exceeds the first threshold, and the PWM signal
generation unit 35, which is a control signal generation
unit that generates, based on the voltage command value, a
20 control signal for causing the inverter 4, which is a first
power conversion unit, to perform conversion operation.
Thus, the deficient amount of electric power for the whole
set of the loads 7 in the station building 1 can be
efficiently supplied.
25 [0039] According to the station building auxiliary power
supply unit 2 according to the first embodiment of the
present invention, the first threshold is set to a value
less than or equal to the capacity of the transformer 9
provided for transforming high-voltage AC power supplied
30 from an AC system into low-voltage AC power to supply
electric power to the loads 7 in the station building 1.
Thus, electric power can be supplied to the loads 7 in the
station building 1 before the whole set of the loads 7 in
20
the station building 1 falls short of electric power, which
may cause a malfunction of the loads 7.
[0040] According to the station building auxiliary power
supply unit 2 according to the first embodiment of the
5 present invention, the start-of-operation determination
unit 32 determines whether the overhead line 6 has a
voltage exceeding the preset second threshold when the
amount of load power indicated in the load power
information does not exceed the first threshold, and when
10 the voltage of the overhead line 6 exceeds the second
threshold, determines to cause the first power conversion
unit to perform conversion operation. Thus, excess
regenerative power can also be effectively supplied to the
loads 7 in the station building 1.
15 [0041] Second Embodiment.
A station building auxiliary power supply unit 2a
according to a second embodiment of the present invention
will next be described. FIG. 6 is a diagram illustrating
an example of configuration of a railway system including
20 the station building auxiliary power supply unit 2a
according to the second embodiment of the present invention.
Note that components and the like similar to the
corresponding ones of the station building auxiliary power
supply unit 2 according to the first embodiment of the
25 present invention are designated by like reference
characters, and detailed description thereof will be
omitted.
[0042] As illustrated in FIG. 6, the station building
auxiliary power supply unit 2a according to the second
30 embodiment receives load state information input from
preset particular ones of the loads 7. Examples of the
particular ones of the loads 7 include multiple platform
screen doors (hereinafter, simply platform doors) and the
21
like installed on a platform in the station building 1.
The multiple platform doors cause the motor(s) provided in
each thereof to operate simultaneously upon operation of
the platform doors, which temporarily causes a rapid
5 increase in power consumption. This causes power
consumption to more widely vary than the power consumption
of other ones of the loads 7 in the station building 1.
This may result in a temporary deficiency of electric power
in the whole set of the loads 7 in the station building 1.
10 Note that the particular ones of the loads 7 are not
limited to platform doors, but, for example, an electrical
installation newly installed in the station building 1 may
be configured as a particular one of the loads 7. In
addition, the particular ones of the loads 7 are not
15 limited to one type of loads 7, but multiple types of loads
7 may be configured as the particular ones of the loads 7.
Note that examples of the load state information include
start information indicating starting of the particular
ones of the loads 7.
20 [0043] FIG. 7 is a diagram illustrating an example of
configuration of a control device 3a of the station
building auxiliary power supply unit 2a according to the
second embodiment of the present invention. As illustrated
in FIG. 7, the control device 3a includes an interface unit
25 31a, a start-of-operation determination unit 32a, a memory
unit 33a, a voltage command value calculation unit 34a, and
a PWM signal generation unit 35a.
[0044] The interface unit 31a periodically (e.g., every
20 ms) obtains, for example, a trolley voltage measurement
30 value (hereinafter referred to as “trolley voltage value”)
output from the voltage sensor 5, and performs analog-todigital (A/D) conversion on the trolley voltage value.
[0045] The start-of-operation determination unit 32a
22
determines, based on the load state information obtained
from the particular ones of the loads 7, whether to cause
the inverter 4 to perform conversion operation to convert
DC power, which is the first electric power, supplied from
5 the overhead line 6 into AC power, which is the second
electric power, usable by the loads 7. The start-ofoperation determination unit 32a also determines whether to
cause the inverter 4 to perform conversion operation based
on the voltage value obtained by the interface unit 31a.
10 For example, when a determination has been made to cause
the inverter 4 to perform conversion operation, the startof-operation determination unit 32a generates a signal
representing the determination to cause the inverter 4 to
perform conversion operation, and outputs the signal to the
15 voltage command value calculation unit 34a.
[0046] The memory unit 33a stores, for example, load
power information indicating the amount of load power
required during operation of the particular ones of the
loads 7, trolley voltage threshold information for use by
20 the start-of-operation determination unit 32a to determine
whether to cause the inverter 4 to perform power conversion
operation, and the like. Similarly to the second threshold
stored in the memory unit 33a of the station building
auxiliary power supply unit 2 according to the first
25 embodiment, the trolley voltage threshold is a threshold
used as a criterion for determining whether to cause the
inverter 4 to perform conversion operation to supply nonutilized excess regenerative power to the various loads 7
in the station building 1 when there are only a few or no
30 other electric vehicles 8 serving a load that consumes
regenerative power returned from an electric vehicle 8 to
the overhead line 6.
[0047] For example, in a case of reception, from the
23
start-of-operation determination unit 32a, of the signal
representing the determination to cause the inverter 4 to
perform conversion operation, the voltage command value
calculation unit 34a calculates a voltage command value
5 dependent on that signal. The voltage command value
calculation unit 34a outputs the voltage command value
calculated to the PWM signal generation unit 35a. The PWM
signal generation unit 35a generates a pulse width
modulation (PWM) signal for controlling the inverter 4,
10 based on the voltage command value input from the voltage
command value calculation unit 34a.
[0048] FIG. 8 is a flowchart illustrating an example of
process performed by the start-of-operation determination
unit 32a of the station building auxiliary power supply
15 unit 2a according to the second embodiment of the present
invention. An example of flow of the process performed by
the start-of-operation determination unit 32a of the
station building auxiliary power supply unit 2a according
to the second embodiment of the present invention will be
20 described below with reference to the flowchart of FIG. 8.
[0049] As illustrated in FIG. 8, at step S401, the
start-of-operation determination unit 32a determines
whether start information has been obtained from particular
ones of the loads 7 as the load state information. If the
25 start information is determined to have been obtained from
particular ones of the loads 7 (Yes) at step S401, the
start-of-operation determination unit 32a determines, at
step S402, to cause the inverter 4 to perform conversion
operation.
30 [0050] At step S403, the start-of-operation
determination unit 32a generates a third signal. For
example, the start-of-operation determination unit 32a
obtains load power information of the particular ones of
24
the loads 7 stored in the memory unit 33a based on the load
state information, i.e., the start information, of the
particular ones of the loads 7 obtained at step S401. Then,
the start-of-operation determination unit 32a generates the
5 third signal including information indicating the
determination to cause the inverter 4 to perform conversion
operation, and including the load power information of the
particular ones of the loads 7 obtained from the memory
unit 33a. At step S404, the start-of-operation
10 determination unit 32a outputs the third signal generated,
to the voltage command value calculation unit 34a.
[0051] If the start information is determined not to
have been obtained from the particular ones of the loads 7
(No) at step S401, the start-of-operation determination
15 unit 32a obtains, at step S405, the trolley voltage value
having been converted into a digital signal, from the
interface unit 31a. Next, at step S406, the start-ofoperation determination unit 32a determines whether the
trolley voltage value obtained at step S405 is greater than
20 or equal to the trolley voltage threshold stored in the
memory unit 33a.
[0052] If the trolley voltage value is determined to be
greater than or equal to the trolley voltage threshold
(Yes) at step S406, the start-of-operation determination
25 unit 32a determines, at step S407, to cause the inverter 4
to perform conversion operation. Then, at step S408, the
start-of-operation determination unit 32a generates a
fourth signal including, for example, information
indicating the determination to cause the inverter 4 to
30 perform conversion operation, and excess regenerative power
presence information indicating that excess regenerative
power is available. At step S409, the start-of-operation
determination unit 32a outputs the fourth signal generated,
25
to the voltage command value calculation unit 34a.
[0053] If the trolley voltage value is determined not to
be greater than or equal to the trolley voltage threshold
(No) at step S406, the start-of-operation determination
5 unit 32a determines, at step S410, whether the inverter 4
is performing conversion operation. If the inverter 4 is
determined to be performing conversion operation (Yes) at
step 410, the start-of-operation determination unit 32a
determines, at step S411, to stop the conversion operation
10 of the inverter 4. If the inverter 4 is performing
changing operation, the start-of-operation determination
unit 32a stops, at step S412, generation and outputting of
the third signal and the fourth signal.
[0054] If the inverter 4 is determined not to be
15 performing conversion operation (No) at step S410, the
start-of-operation determination unit 32a determines, at
step S413, not to cause the inverter 4 to perform
conversion operation. Note that the start-of-operation
determination unit 32a periodically repeats the process at
20 and after step S401.
[0055] FIG. 9 is a flowchart illustrating an example of
process performed by the voltage command value calculation
unit 34a of the station building auxiliary power supply
unit 2a according to the second embodiment of the present
25 invention. An example of flow of the process performed by
the voltage command value calculation unit 34a of the
station building auxiliary power supply unit 2a according
to the second embodiment of the present invention will be
described below with reference to the flowchart of FIG. 9.
30 [0056] As illustrated in FIG. 9, at step S501, the
voltage command value calculation unit 34a determines
whether the third signal has been input from the start-ofoperation determination unit 32a. If the third signal is
26
determined to have been input (Yes) at step S501, the
voltage command value calculation unit 34a calculates a
voltage command value, at step S502, based on, for example,
the load power information of the particular ones of the
5 loads 7 included in the third signal. That is, the voltage
command value calculation unit 34a calculates a voltage
command value taking into account the amount of load power
required during operation of the particular ones of the
loads 7. Then, at step S503, the voltage command value
10 calculation unit 34a outputs the voltage command value
calculated at step S502, to the PWM signal generation unit
35a.
[0057] Otherwise, if the third signal is determined not
to have been input (No) at step S501, the voltage command
15 value calculation unit 34a determines, at S504, whether the
fourth signal has been input from the start-of-operation
determination unit 32a. If the fourth signal is determined
to have been input (Yes) at step S504, the voltage command
value calculation unit 34a understands, at S505, that
20 excess regenerative power is available based on the excess
regenerative power presence information included in the
fourth signal, and calculates a voltage command value based
on, for example, a preset setting value of electric power
to be consumed in the station building auxiliary power
25 supply unit 2a in presence of excess regenerative power.
Then, at step S503, the voltage command value calculation
unit 34a outputs the voltage command value calculated at
step S505, to the PWM signal generation unit 35a.
Otherwise, if the fourth signal is determined not to have
30 been input (No) at step S504, the voltage command value
calculation unit 34a repeats the process at and after step
S501. Note that the PWM signal generation unit 35a of the
station building auxiliary power supply unit 2a according
27
to the second embodiment operates similarly to the PWM
signal generation unit 35 of the station building auxiliary
power supply unit 2 according to the first embodiment as
illustrated in FIG. 5, and detailed description thereof
5 will therefore be omitted.
[0058] Note that the station building auxiliary power
supply unit 2a according to the second embodiment of the
present invention has been described using an example in
which start information is input as the load state
10 information from particular ones of the loads 7. However,
the load state information is not limited thereto, but, for
example, in a case in which the particular ones of the
loads 7 are platform doors, position information of a
specific one of the electric vehicles 8 (hereinafter,
15 specific electric vehicle 8) that enters and stops in the
station building 1 including platform doors installed
therein may be obtained as the load state information. In
this case, the start-of-operation determination unit 32a
generates the third signal, for example, upon detection
20 that the specific electric vehicle 8 has reached a preset
specific position, based on the position information of the
specific electric vehicle 8. Note that the specific
position is set to a position short of the stop position of
the electric vehicles. The platform doors start an opening
25 and closing operation after the specific electric vehicle 8
stops at the stop position in the station building 1. Thus,
the station building auxiliary power supply unit 2a causes
the inverter 4 to perform conversion operation when the
specific electric vehicle 8 reaches the specific position
30 short of the stop position of the electric vehicles 8,
which thus enables electric power to be supplied to the
whole set of the loads 7 in the station building 1 before
the specific electric vehicle 8 stops and the platform
28
doors perform opening and closing operation. This can
reliably prevent a temporary deficiency of electric power
in the whole set of the loads 7 in the station building 1.
[0059] Note that the method used by the station building
5 auxiliary power supply unit 2a for obtaining the position
information of an electric vehicle 8 is not particularly
limited, but, for example, the station building auxiliary
power supply unit 2a may directly receive, via wireless
communication, the position information of an electric
10 vehicle 8 generated by an on-vehicle control device
installed in that electric vehicle 8. Alternatively, the
station building auxiliary power supply unit 2a may allow
the position information of an electric vehicle 8 to be
transmitted from an on-vehicle control device to a wayside
15 control device via wireless communication, and then receive
the position information of that electric vehicle 8 via a
wire or wirelessly. Further alternatively, the station
building auxiliary power supply unit 2a may receive
information indicating that an electric vehicle 8 has
20 reached a specific position, instead of the position
information of that electric vehicle 8. For example, the
station building auxiliary power supply unit 2a may set, as
the specific position, the position of a wayside device
installed at a position short of the stop position of the
25 electric vehicles 8, and obtain, from the wayside device,
information indicating that an electric vehicle 8 has
reached the specific position when the electric vehicle 8
reaches the position of the wayside device. In this case,
there is no need for the start-of-operation determination
30 unit 32a to detect that an electric vehicle 8 has reached a
preset specific position based on the position information
of that electric vehicle 8, but it is sufficient to
generate the third signal upon reception of the information
29
indicating that an electric vehicle 8 has reached the
specific position.
[0060] In addition, the particular ones of the loads 7
may also be, for example, an elevator or an escalator. In
5 a case in which the particular ones of the loads 7 include
an elevator, for example, the load state information may be
start information indicating starting of operation
triggered by a user pressing an operation button. In a
case in which the particular ones of the loads 7 include an
10 escalator, for example, the load state information may be
start information indicating starting of operation
triggered by a human detection sensor having detected a
user during a stand-by state of the escalator.
[0061] Moreover, the station building auxiliary power
15 supply unit 2a according to the second embodiment can be
combined with the station building auxiliary power supply
unit 2 according to the first embodiment. For example,
similarly to the station building auxiliary power supply
unit 2 according to the first embodiment, the station
20 building auxiliary power supply unit 2a may be configured
to also obtain, from the electric power detection unit 10,
the load power value representing the total amount of
electric power being consumed by the various loads 7. In
such case, the start-of-operation determination unit 32a of
25 the station building auxiliary power supply unit 2a also
makes, for example, a determination at step S102
illustrated in FIG. 3 as to whether the load power value is
greater than or equal to the first threshold, in addition
to the determination at step S401 illustrated in FIG. 8 as
30 to whether start information has been obtained as the load
state information of particular ones of the loads 7. That
is, even when the start information of the particular ones
of the loads 7 has not been obtained, the start-of-
30
operation determination unit 32a determines to cause the
inverter 4 to perform conversion operation, and generates
and outputs the first signal as illustrated at steps S103
to S105 of FIG. 3 if the load power value is greater than
5 or equal to the first threshold. Otherwise, even when the
load power value is less than the first threshold, the
start-of-operation determination unit 32a determines to
cause the inverter 4 to perform conversion operation, and
generates and outputs the third signal as illustrated at
10 steps S402 to S404 of FIG. 8 if the start information of
the particular ones of the loads 7 has been obtained. In
addition, if the start information of the particular ones
of the loads 7 has been obtained, and the load power value
is greater than or equal to the first threshold, which load
15 power value detected by the voltage detection unit 10 also
includes the load power value of the particular ones of the
loads 7, it is sufficient for the start-of-operation
determination unit 32a to generate and output the first
signal. Further alternatively, if, for example, the start
20 information of the particular ones of the loads 7 has been
obtained, and the load power value is greater than or equal
to the first threshold, which load power value detected by
the voltage detection unit 10 does not include the load
power value of the particular ones of the loads 7, the
25 start-of-operation determination unit 32a may generate a
signal including the load power information of the
particular ones of the loads 7 obtained from the memory
unit 33a and including the power deficiency information
indicating the difference between the load power value and
30 the first threshold. In this case, the voltage command
value calculation unit 34a calculates the voltage command
value based on the load power information of the particular
ones of the loads 7 and on the power deficiency information
31
indicating the difference between the load power value and
the first threshold.
[0062] According to the station building auxiliary
electric unit 2a according to the second embodiment of the
5 present invention, the start-of-operation determination
unit 32a determines to cause the inverter 4, which is a
first power conversion unit, to perform conversion
operation when the load state information of preset
particular ones of the loads 7 has been input. Thus,
10 electric power can be supplied to the whole set of the
loads 7 in the station building 1 regardless of
availability of excess regenerative power. This can
prevent deficiency of electric power that would be caused
by operation of the particular ones of the loads 7 in the
15 station building 1.
[0063] According to the station building auxiliary
electric unit 2a according to the second embodiment of the
present invention, the particular ones of the loads 7 are
platform doors installed in the station building 1.
20 Therefore, even when a rapid increase in power consumption
is temporarily caused upon operation of the platform doors,
electric power can be supplied to the whole set of the
loads 7 in the station building 1, which can, in turn,
prevent a deficiency of electric power that would be caused
25 by operation of the platform doors, regardless of
availability of excess regenerative power.
[0064] According to the station building auxiliary
electric unit 2a according to the second embodiment of the
present invention, the load state information is position
30 information of a specific one of the electric vehicles 8
that enters and stops in the station building 1 including
platform doors installed therein, and the start-ofoperation determination unit 32a determines, based on the
32
position information, to cause the inverter 4, which is a
first power conversion unit, to perform conversion
operation. Thus, the start-of-operation determination unit
32a can cause the inverter 4 to perform conversion
5 operation before a specific electric vehicle 8 stops and
the platform doors perform opening and closing operation.
This enables the station building auxiliary electric unit
2a to supply electric power to the whole set of the loads 7
in the station building 1 before the platform doors perform
10 opening and closing operation. This can reliably prevent a
temporary deficiency of electric power that would be caused
by opening and closing operation of the platform doors, in
the whole set of the loads 7 in the station building 1.
[0065] The station building auxiliary electric unit 2a
15 according to the second embodiment of the present invention
includes the memory unit 33a, which stores load power
information indicating the amount of load power required
during operation of particular ones of the loads 7; the
voltage command value calculation unit 34a, which
20 calculates a voltage command value based on the load power
information when the start-of-operation determination unit
32a determines to cause the inverter 4, which is a first
power conversion unit, to perform conversion operation; and
the PWM signal generation unit 35a, which is a control
25 signal generation unit that generates a control signal that
causes the inverter 4 to perform conversion operation,
based on the voltage command value. The station building
auxiliary power supply unit 2a can thus efficiently supply
electric power in the amount of possible deficiency in the
30 whole set of the loads 7 in the station building 1 that
would be caused by operation of the particular ones of the
loads 7.
[0066] According to the station building auxiliary
33
electric unit 2a according to the second embodiment of the
present invention, when the load state information of the
particular ones of the loads 7 has not been input, the
start-of-operation determination unit 32a determines
5 whether the overhead line 6 has a voltage exceeding a
preset trolley voltage threshold, and if the voltage of the
overhead line 6 exceeds the trolley voltage threshold,
determines to cause the inverter 4, which is a first power
conversion unit, to perform conversion operation. This
10 enables excess regenerative power to be effectively
supplied to the loads 7 in the station building 1.
[0067] Third Embodiment.
A station building auxiliary power supply unit 2b
according to a third embodiment of the present invention
15 will next be described. FIG. 10 is a diagram illustrating
an example of configuration of a railway system including
the station building auxiliary power supply unit 2b
according to the third embodiment of the present invention.
Note that components and the like similar to the
20 corresponding ones of the station building auxiliary power
supply unit 2 or 2a according to the first or second
embodiment of the present invention are designated by like
reference characters, and detailed description thereof will
be omitted.
25 [0068] As illustrated in FIG. 10, in addition to the
components of the station building auxiliary power supply
unit 1 according to the first embodiment, the station
building auxiliary power supply unit 2b according to the
second embodiment also includes an electricity storage unit
30 11, which stores excess regenerative power supplied from
the overhead line 6, a converter (second power conversion
unit) 12, which is disposed between the overhead line 6 and
the electricity storage unit 11, and performs power
34
conversion on the excess regenerative power to supply the
resulting power to the electricity storage unit 11, and an
amount-of-charge detection unit 13, which detects the
amount of charge in the electricity storage unit 11.
5 [0069] FIG. 11 is a diagram illustrating an example of
configuration of a control device 3b of the station
building auxiliary power supply unit 2b according to the
third embodiment of the present invention. As illustrated
in FIG. 11, the control device 3b includes an interface
10 unit 31b, a start-of-operation determination unit 32b, a
memory unit 33b, a voltage command value calculation unit
34b, and a PWM signal generation unit 35b.
[0070] The interface unit 31b periodically (e.g., every
20 ms) obtains, for example, a trolley voltage measurement
15 value (hereinafter referred to as “trolley voltage value”)
output from the voltage sensor 5, and performs analog-todigital (A/D) conversion on the trolley voltage value. The
interface unit 31b also obtains load state information
indicating the operational state of the loads 7. In the
20 present embodiment, the interface unit 31b periodically
(e.g., every 20 ms) obtains, as the load state information,
for example, load power information output from the
electric power detection unit 10, indicating the load power
value that is the total amount of electric power being
25 consumed by the various loads 7 that are in operation. The
interface unit 31b then performs analog-to-digital (A/D)
conversion on the electric power value. The interface unit
31b further obtains, from the amount-of-charge detection
unit 13, amount-of-charge information representing the
30 amount of charge charged in the electricity storage unit 11.
[0071] The start-of-operation determination unit 32b
determines, based on, for example, the load state
information and the amount-of-charge information obtained
35
by the interface unit 31b, whether to cause the inverter 4
to perform conversion operation to convert DC power, which
is the first electric power, supplied from the overhead
line 6 into AC power, which is the second electric power,
5 usable by the loads 7, or to convert the charged power
stored in the electricity storage unit 11 to AC power
usable by the loads 7. The start-of-operation
determination unit 32b also determines whether to cause the
inverter 4 or the converter 12 to perform conversion
10 operation, based on the trolley voltage value and on the
amount-of-charge information obtained by the interface unit
31b. When a determination has been made, for example, to
cause the inverter 4 or the converter 12 to perform
conversion operation, the start-of-operation determination
15 unit 32b generates a signal representing the determination
to cause the inverter 4 or the converter 12 to perform
conversion operation, and outputs the signal to the voltage
command value calculation unit 34b.
[0072] The memory unit 33b stores, for example, the
20 first threshold, the second threshold, and an amount-ofcharge threshold for use by the start-of-operation
determination unit 32b to determine whether to cause the
inverter 4 or the converter 12 to perform conversion
operation. The first threshold is used for comparison with
25 the load power value indicated in the load power
information output from the electric power detection unit
10. The amount-of-charge threshold is preset based on the
capacity of the electricity storage unit 11 or the like,
and is used for comparison with the amount of charge of the
30 electricity storage unit 11 output from the amount-ofcharge detection unit 13.
[0073] For example, in a case of reception, from the
start-of-operation determination unit 32b, of a signal
36
representing the determination to cause the inverter 4 or
the converter 12 to perform conversion operation, the
voltage command value calculation unit 34b calculates a
voltage command value dependent on that signal. The
5 voltage command value calculation unit 34b outputs the
voltage command value calculated to the PWM signal
generation unit 35b. The PWM signal generation unit 35b
generates a pulse width modulation (PWM) signal for
controlling the inverter 4 or the converter 12, based on,
10 for example, the voltage command value input from the
voltage command value calculation unit 34b.
[0074] FIGS. 12 and 13 are flowcharts illustrating an
example of process performed by the start-of-operation
determination unit 32b of the station building auxiliary
15 power supply unit 2b according to the third embodiment of
the present invention. An example of flow of the process
performed by the start-of-operation determination unit 32b
of the station building auxiliary power supply unit 2b
according to the third embodiment of the present invention
20 will be described below with reference to the flowcharts of
FIGS. 12 and 13.
[0075] As illustrated in FIG. 12, at step S601, the
start-of-operation determination unit 32b obtains, from the
interface unit 31a, the trolley voltage value having been
25 converted into a digital signal, the load power information
representing the sum of the amounts of electric power being
consumed by the various loads 7 that are in operation, and
the amount-of-charge information representing the amount of
charge charged in the electricity storage unit 11. Next,
30 at step S602, the start-of-operation determination unit 32b
determines whether the load power value obtained at step
S601 is greater than or equal to the first threshold stored
in the memory unit 33b.
37
[0076] If the load power value is determined to be
greater than or equal to the first threshold (Yes) at step
S602, the start-of-operation determination unit 32b
determines, at step S603, whether the amount of charge is
5 greater than or equal to the charge threshold stored in the
memory unit 33b. If the amount of charge is determined to
be greater than or equal to the charge threshold (Yes) at
step 603, the start-of-operation determination unit 32b
determines, at S604, to cause the inverter 4 to perform
10 conversion operation to supply electric power to the whole
set of the loads 7 in the station building 1, from the
electricity storage unit 11. Then, at step S605, the
start-of-operation determination unit 32b generates a fifth
signal including, for example, information indicating the
15 determination to cause the inverter 4 to perform conversion
operation, information indicating the determination to
supply electric power from the electricity storage unit 11,
and power deficiency information indicating the difference
between the load power value and the first threshold. At
20 step S606, the start-of-operation determination unit 32b
outputs the fifth signal generated, to the voltage command
value calculation unit 34b.
[0077] If the amount of charge is determined not to be
greater than or equal to the charge threshold (No) at step
25 603, the start-of-operation determination unit 32b
determines, at S607, to cause the inverter 4 to perform
conversion operation to supply electric power to the whole
set of the loads 7 in the station building 1, from the
overhead line 6. Then, at step S608, the start-of30 operation determination unit 32b generates a sixth signal
including, for example, information indicating the
determination to cause the inverter 4 to perform conversion
operation, information indicating the determination to
38
supply electric power from the overhead line 6, and power
deficiency information indicating the difference between
the load power value and the first threshold. At step S609,
the start-of-operation determination unit 32b outputs the
5 sixth signal generated, to the voltage command value
calculation unit 34b.
[0078] If the load power value is determined not to be
greater than or equal to the first threshold (No) at step
S602, the start-of-operation determination unit 32b
10 determines, at step S610, whether the trolley voltage value
is greater than or equal to the second threshold stored in
the memory unit 33b.
[0079] If the trolley voltage value is determined to be
greater than or equal to the second threshold (Yes) at step
15 S610, the start-of-operation determination unit 32b
determines, at step S611, to cause the inverter 4 and the
converter 12 to perform conversion operation to charge the
electricity storage unit 11, and to supply electric power
to the whole set of the loads 7 in the station building 1,
20 using excess regenerative power from the overhead line 6.
Then, at step S612, the start-of-operation determination
unit 32b generates a seventh signal including, for example,
information indicating the determination to cause the
inverter 4 to perform conversion operation, information
25 indicating the determination to cause the converter 12 to
perform conversion operation, and excess regenerative power
presence information indicating that excess regenerative
power is available. At step S613, the start-of-operation
determination unit 32b outputs the seventh signal generated,
30 to the voltage command value calculation unit 34b. Note
that if the amount of charge of the electricity storage
unit 11 reaches a full charge capacity at step S611, the
start-of-operation determination unit 32b determines to
39
cause the inverter 4 to perform conversion operation to
supply electric power to the whole set of the loads 7 in
the station building 1 without charging the electricity
storage unit 11.
5 [0080] If the trolley voltage value is determined not to
be greater than or equal to the second threshold (No) at
step S610, the start-of-operation determination unit 32b
determines, at step S614 illustrated in FIG. 13, whether
the amount of charge of the electricity storage unit 11 is
10 greater than or equal to the charge threshold stored in the
memory unit 33b. Note that FIG. 13 illustrates the detail
of process A after the start-of-operation determination
unit 32b has determined that the trolley voltage value is
not greater than or equal to the second threshold (No) in
15 the process at step S610 of FIG. 12.
[0081] If the amount of charge of the electricity
storage unit 11 is determined to be greater than or equal
to the charge threshold (Yes) at step S614, the start-ofoperation determination unit 32b determines, at S615, to
20 cause the inverter 4 to perform conversion operation to
supply electric power to the whole set of the loads 7 in
the station building 1, from the electricity storage unit
11. Then, at step S616, the start-of-operation
determination unit 32b generates an eighth signal including,
25 for example, information indicating the determination to
cause the inverter 4 to perform conversion operation, and
information indicating the determination to supply electric
power from the electricity storage unit 11. At step S617,
the start-of-operation determination unit 32b outputs the
30 eighth signal generated, to the voltage command value
calculation unit 34b.
[0082] If the amount of charge of the electricity
storage unit 11 is determined not to be greater than or
40
equal to the charge threshold (No) at step S614, the startof-operation determination unit 32b determines, at S618,
whether the inverter 4 or the converter 12 is performing
conversion operation. If at least one of the inverter 4
5 and the converter 12 is determined to be performing
conversion operation (Yes) at step S618, the start-ofoperation determination unit 32b determines, at step S619,
to stop the conversion operation of the inverter 4 and the
converter 12. If at least one of the inverter 4 and the
10 converter 12 is performing conversion operation, the startof-operation determination unit 32b stops, at step S620,
generation and outputting of the fifth through eighth
signals.
[0083] If the inverter 4 and the converter 12 are both
15 determined not to be performing conversion operation (No)
at step S618, the start-of-operation determination unit 32b
determines not to cause the inverter 4 or the converter 12
to perform conversion operation. Note that the start-ofoperation determination unit 32b repeats the process at and
20 after step S602, for example, each time the trolley voltage
value and the load power value are obtained. Meanwhile,
the amount-of-charge information from the amount-of-charge
detection unit 13 may be obtained between steps S602 and
S603 illustrated in FIG. 12 or between step S610
25 illustrated in FIG. 12 and step S614 illustrated in FIG. 13.
Moreover, although the determinations at step S603 and at
step S614 use a same charge threshold, these determinations
may be made based on different charge thresholds.
[0084] FIG. 14 is a flowchart illustrating an example of
30 process performed by the voltage command value calculation
unit 34b of the station building auxiliary power supply
unit 2b according to the third embodiment of the present
invention. An example of flow of the process performed by
41
the voltage command value calculation unit 34b of the
station building auxiliary power supply unit 2b according
to the third embodiment of the present invention will be
described below with reference to the flowchart of FIG. 14.
5 [0085] As illustrated in FIG. 14, at step S701, the
voltage command value calculation unit 34b determines
whether the fifth signal has been input from the start-ofoperation determination unit 32b. If the fifth signal is
determined to have been input (Yes) at step S701, the
10 voltage command value calculation unit 34b calculates a
voltage command value based on, for example, the fifth
signal at step S702. The voltage command value based on
the fifth signal is provided to cause the inverter 4 to
perform conversion operation to supply electric power from
15 the electricity storage unit 11 to the whole set of the
loads 7 in the station building 1, and is calculated based
on the power deficiency information indicating the
difference between the load power value and the first
threshold. Then, at step S703, the voltage command value
20 calculation unit 34b outputs the voltage command value
calculated at step S702, to the PWM signal generation unit
35b.
[0086] If the fifth signal is determined not to have
been input (No) at step S701, the voltage command value
25 calculation unit 34b determines, at S704, whether the sixth
signal has been input from the start-of-operation
determination unit 32b. If the sixth signal is determined
to have been input (Yes) at step S704, the voltage command
value calculation unit 34b calculates a voltage command
30 value, at S705, based on the sixth signal. The voltage
command value based on the sixth signal is provided to
cause the inverter 4 to perform conversion operation to
supply electric power from the overhead line 6 to the whole
42
set of the loads 7 in the station building 1, and is
calculated based on the power deficiency information
indicating the difference between the load power value and
the first threshold. Then, at step S703, the voltage
5 command value calculation unit 34b outputs the voltage
command value calculated at step S705, to the PWM signal
generation unit 35b.
[0087] If the sixth signal is determined not to have
been input (No) at step S704, the voltage command value
10 calculation unit 34b determines, at S706, whether the
seventh signal has been input from the start-of-operation
determination unit 32b. If the seventh signal is
determined to have been input (Yes) at step S706, the
voltage command value calculation unit 34b calculates a
15 voltage command value, at S707, based on the seventh signal.
The voltage command value based on the seventh signal is
provided to cause the inverter 4 and the converter 12 to
perform conversion operation to charge excess regenerative
power in the electricity storage unit 11 and to supply
20 electric power to the whole set of the loads 7 in the
station building 1, and is calculated based on, for example,
a preset setting value of electric power to be consumed in
the station building auxiliary power supply unit 2b in
presence of excess regenerative power. Then, at step S703,
25 the voltage command value calculation unit 34b outputs the
voltage command value calculated at step S707, to the PWM
signal generation unit 35b.
[0088] If the seventh signal is determined not to have
been input (No) at step S706, the voltage command value
30 calculation unit 34b determines, at S708, whether the
eighth signal has been input from the start-of-operation
determination unit 32b. If the eighth signal is determined
to have been input (Yes) at step S708, the voltage command
43
value calculation unit 34b calculates a voltage command
value, at S709, based on the eighth signal. The voltage
command value based on the eighth signal is provided to
cause the inverter 4 to perform conversion operation to
5 supply electric power from the electricity storage unit 11
to the whole set of the loads 7 in the station building 1,
and is calculated based on, for example, a preset setting
value of electric power. Then, at step S703, the voltage
command value calculation unit 34b outputs the voltage
10 command value calculated at step S709, to the PWM signal
generation unit 35b. Alternatively, if the eighth signal
is determined not to have been input (No) at step S708, the
voltage command value calculation unit 34 repeats the
process at and after step S701.
15 [0089] FIG. 15 is a flowchart illustrating an example of
process performed by the PWM signal generation unit 35b of
the station building auxiliary power supply unit 2b
according to the third embodiment of the present invention.
An example of flow of the process performed by the PWM
20 signal generation unit 35b of the station building
auxiliary power supply unit 2b according to the third
embodiment of the present invention will be described below
with reference to the flowchart of FIG. 15.
[0090] As illustrated in FIG. 15, at step S801, the PWM
25 signal generation unit 35b receives the voltage command
value input from the voltage command value calculation unit
34b. At step S802, the PWM signal generation unit 35b
generates a PWM signal for controlling the conversion
operation of the inverter 4 or of the converter 12 based on
30 the voltage command value input at step S801. Then, at
step S303, the PWM signal generation unit 35b outputs the
PWM signal generated at step S302 to the inverter 4 or to
the converter 12. The inverter 4 and the converter perform
44
conversion operation based on the PWM signal input from the
PWM signal generation unit 35b.
[0091] Note that a configuration including the
electricity storage unit 11, which stores excess
5 regenerative power supplied from the overhead line 6, the
converter (second power conversion unit) 12, which is
disposed between the overhead line 6 and the electricity
storage unit 11, and performs power conversion on the
excess regenerative power to supply the resulting power to
10 the electricity storage unit 11, and the amount-of-charge
detection unit 13, which detects the amount of charge of
the electricity storage unit 11, such as the configuration
of the station building auxiliary power supply unit 2b
according to the third embodiment of the present invention
15 is also applicable to the station building auxiliary power
supply unit 2a according to the second embodiment. In this
case, the memory unit 33a of the station building auxiliary
power supply unit 2a according to the second embodiment is
configured to previously store the amount-of-charge
20 threshold for use by the start-of-operation determination
unit 31a for comparison with the amount of charge output
from the amount-of-charge detection unit 13.
[0092] Then, by way of example, the start-of-operation
determination unit 31a determines whether the stored amount
25 of electricity is greater than or equal to the amount-ofcharge threshold between step S401 and step S402
illustrated in FIG. 8. Then, if the load state information
has been obtained from particular ones of the loads 7, and
the amount of charge is greater than or equal to the
30 amount-of-charge threshold, the start-of-operation
determination unit 31a determines to cause the inverter 4
to perform conversion operation to supply electric power to
the whole set of the loads 7 in the station building 1,
45
from the electricity storage unit 11. If the load state
information has been obtained from particular ones of the
loads 7, and the amount of charge is less than the amountof-charge threshold, the start-of-operation determination
5 unit 31a determines to cause the inverter to perform
conversion operation to supply electric power to the whole
set of the loads 7 in the station building 1, from the
overhead line 6. Thus, the station building auxiliary
power supply unit 2b can supplement the supply of electric
10 power to the loads 7 in the station building 1 without
using electric power from the overhead line 6 even when no
excess regenerative power is available when the amount of
charge of the electricity storage unit 11 is greater than
or equal to the amount-of-charge threshold.
15 [0093] The station building auxiliary electric unit 2b
according to the third embodiment of the present invention
includes the electricity storage unit 11, which stores
excess regenerative power supplied from the overhead line
6; the converter 12, i.e., a second power conversion unit,
20 which is disposed between the overhead line 6 and the
electricity storage unit 11, and performs power conversion
on the excess regenerative power to supply the resulting
power to the electricity storage unit 11 when the voltage
of the overhead line 6 exceeds the second threshold; and
25 the amount-of-charge detection unit 13, which detects the
amount of charge of the electricity storage unit 11. The
start-of-operation determination unit 31b determines
whether the amount of charge detected by the amount-ofcharge detection unit 13 is greater than or equal to a
30 preset amount-of-charge threshold when the amount of load
power indicated in the load power information exceeds the
first threshold; and if the amount of charge is greater
than or equal to the amount-of-charge threshold, determines
46
to cause the inverter 4 to perform conversion operation to
supply electric power to the loads 7 from the electricity
storage unit 11, and if, alternatively, the amount of
charge is less than the amount-of-charge threshold,
5 determines to cause the inverter 4 to perform conversion
operation to supply electric power to the loads 7 from the
overhead line 6. Thus, the supply of electric power to the
loads 7 in the station building 1 can be supplemented
regardless of availability of excess regenerative power.
10 Moreover, when the amount of charge of the electricity
storage unit 11 is greater than or equal to the amount-ofcharge threshold, the supply of electric power to the loads
7 in the station building 1 can be supplemented without
using electric power from the overhead line 6 even when no
15 excess regenerative power is available.
[0094] Note that the control devices 3 to 3b of the
station building auxiliary power supply units 2 to 2b
according to the respective first through third embodiments
of the present invention each include, for example, a
20 processor and a memory, and the operation of each unit can
be implemented in software. FIG. 16 is a diagram
illustrating an example of hardware configuration for
implementing the control devices 3 to 3b of the station
building auxiliary power supply units 2 to 2b according to
25 the respective first through third embodiments of the
present invention. As illustrated in FIG. 16, the control
devices 3 to 3b of the station building auxiliary power
supply units 2 to 2b according to the respective first
through third embodiments of the present invention each
30 include a processor 91 and a memory 92. The processor 91
and the memory 92 are connected to each other via a system
bus 93. The processor 91 performs computation and control
by software using input data. The memory 92 stores input
47
data, or data and a program needed for computation and
control performed by the processor 91. Note that multiple
processors 91 and multiple memories 92 may be provided.
[0095] Note that although the station building auxiliary
5 power supply units 2 to 2b according to the first through
third embodiments of the present invention have been
described using an example in which electric power from the
DC overhead line 6 is supplied to the whole set of the
loads 7 in the station building 1, the power source line is
10 not limited to the DC overhead line 6, but the present
invention is also applicable to an AC overhead line.
[0096] Note that the present invention is not limited to
the embodiments described, but modifications and omissions
may be made as appropriate to the embodiments without
15 departing from the scope of the spirit of the present
invention.
Reference Signs List
[0097] 1 station building; 2-2b station building
20 auxiliary power supply unit; 3-3b control device; 4
inverter (first power conversion unit); 5 voltage sensor;
6 overhead line; 7, 7-1-7-n load; 8 electric vehicle; 9
transformer; 10 electric power detection unit; 11
electricity storage unit; 12 converter (second power
25 conversion unit); 13 amount-of-charge detection unit; 31-
31b interface unit; 32-32b start-of-operation
determination unit; 33-33b memory unit; 34-34b voltage
command value calculation unit; 35-35b PWM signal
generation unit; 100 electric power substation; 200 AC
30 system.
48
We Claim :
1. A station building auxiliary power supply unit
comprising:
a first power conversion unit to convert first
5 electric power supplied from an overhead line into second
electric power usable by loads installed in a station
building; and
a start-of-operation determination unit to determine
whether to cause the first power conversion unit to perform
10 conversion operation, based on load state information
indicating an operational state of the loads.
2. The station building auxiliary power supply unit
according to claim 1, wherein
15 the load state information includes load power
information indicating an amount of load power consumed by
the loads, and
when the amount of load power indicated in the load
power information exceeds a first threshold that has been
20 preset, the start-of-operation determination unit
determines to cause the first power conversion unit to
perform conversion operation.
3. The station building auxiliary power supply unit
25 according to claim 2, wherein the load power information is
information indicating a total amount of the load power
consumed by the plurality of loads installed in the station
building.
30 4. The station building auxiliary power supply unit
according to claim 2 or 3, comprising:
a voltage command value calculation unit to calculate
a voltage command value based on a difference between the
49
amount of load power indicated in the load power
information and the first threshold when the amount of load
power indicated in the load power information exceeds the
first threshold; and
5 a control signal generation unit to generate a control
signal that causes the first power conversion unit to
perform conversion operation, based on the voltage command
value.
10 5. The station building auxiliary power supply unit
according to any one of claims 2 to 4, wherein the first
threshold is set to a value less than or equal to a
capacity of a transformer for transforming high-voltage
alternating current power supplied from an alternating
15 current system into low-voltage alternating current power
to supply electric power to the loads in the station
building.
6. The station building auxiliary power supply unit
20 according to any one of claims 2 to 5, wherein when the
amount of load power indicated in the load power
information does not exceed the first threshold, the startof-operation determination unit determines whether the
overhead line has a voltage exceeding a second threshold
25 that has been preset, and if the voltage of the overhead
line exceeds the second threshold, determines to cause the
first power conversion unit to perform conversion operation.
7. The station building auxiliary power supply unit
30 according to claim 6, comprising:
an electricity storage unit to store excess
regenerative power supplied from the overhead line;
a second power conversion unit disposed between the
50
overhead line and the electricity storage unit to perform
power conversion on the excess regenerative power to supply
resulting power to the electricity storage unit when the
voltage of the overhead line exceeds the second threshold;
5 and
an amount-of-charge detection unit to detect an amount
of charge of the electricity storage unit, wherein
when the amount of load power indicated in the load
power information exceeds the first threshold, the start10 of-operation determination unit determines whether the
amount of charge detected by the amount-of-charge detection
unit is greater than or equal to an amount-of-charge
threshold that has been preset, and
if the amount of charge is greater than or equal
15 to the amount-of-charge threshold, the start-of-operation
determination unit determines to cause the first power
conversion unit to perform conversion operation to supply
electric power to the loads from the electricity storage
unit, and
20 if the amount of charge is less than the amountof-charge threshold, the start-of-operation determination
unit determines to cause the first power conversion unit to
perform conversion operation to supply electric power to
the loads from the overhead line.
25
8. The station building auxiliary power supply unit
according to claim 1, wherein the start-of-operation
determination unit determines to cause the first power
conversion unit to perform conversion operation when the
30 load state information of a particular one that has been
preset among the loads has been input.
9. The station building auxiliary power supply unit
51
according to claim 8, wherein the particular one of the
loads is a platform screen door installed in the station
building.
5 10. The station building auxiliary power supply unit
according to claim 9, wherein
the load state information is position information of
an electric vehicle that enters and stops in the station
building including the platform screen doors, and
10 the start-of-operation determination unit determines
to cause the first power conversion unit to perform
conversion operation based on the position information.
11. The station building auxiliary power supply unit
15 according to any one of claims 8 to 10, comprising:
a memory unit to store load power information
indicating an amount of load power required during
operation of the particular one of the loads;
a voltage command value calculation unit to calculate
20 a voltage command value based on the load power information
when the start-of-operation determination unit determines
to cause the first power conversion unit to perform
conversion operation; and
a control signal generation unit to generate a control
25 signal that causes the first power conversion unit to
perform conversion operation, based on the voltage command
value.
12. The station building auxiliary power supply unit
30 according to any one of claims 8 to 11, wherein when the
load state information of the particular one of the loads
has not been input, the start-of-operation determination
unit determines whether the overhead line has a voltage
52
exceeding a trolley voltage threshold that has been preset,
and if the voltage of the overhead line exceeds the trolley
voltage threshold, determines to cause the first power
conversion unit to perform conversion operation.
5
13. The station building auxiliary power supply unit
according to claim 12, comprising:
an electricity storage unit to store excess
regenerative power supplied from the overhead line;
10 a second power conversion unit disposed between the
overhead line and the electricity storage unit to perform
power conversion on the excess regenerative power to supply
resulting power to the electricity storage unit when the
load state information of the particular one of the loads
15 has not been input; and
an amount-of-charge detection unit to detect an amount
of charge of the electricity storage unit, wherein
when the load state information of the particular one
of the loads has been input, the start-of-operation
20 determination unit determines whether the amount of charge
detected by the amount-of-charge detection unit is greater
than or equal to an amount-of-charge threshold that has
been preset, and
if the amount of charge is greater than or equal
25 to the amount-of-charge threshold, the start-of-operation
determination unit determines to cause the first power
conversion unit to perform conversion operation to supply
electric power to the loads from the electricity storage
unit, and
30 if the amount of charge is less than the amountof-charge threshold, the start-of-operation determination
unit determines to cause the first power conversion unit to
perform conversion operation to supply electric power to

the loads from the overhead line.