DESCRIPTION
Title of Invention
CHARGING FACILITY AND ENERGY MANAGEMENT METHOD FOR
CHARGING FACILITY
Technical Field
[OOO 11
The present invention relates to a fast charging facility for an electric vehicle
10 linked with a power generation device, such as a solar power generation module, or a
chargingldischarging device, such as a fixed storage battery, and can be suitably applied
to an energy management method for each device associated with the charging facility.
Background Art
15 [0002]
At the time of fast charging of an electric vehicle, power which is consumed at
the time of traveling of the electric vehicle should be supplied in a comparatively short
charging time. In other words, a large load is applied to a so-called system power
supply, that is, a power facility which supplies commercial power, in inverse proportion
20 to the shortness of the charging time of the electric vehicle.
[0003]
In addition, since the time zone during which fast charging of the electric
vehicle is required depends on the life pattern of a driver, hereafter, if the electric
vehicles become more popular, fast charging may be intensively performed according to
25 the season, a day of the week, a time zone, or the like. Accordingly, controlling
2
smoothing power demand for a short period of time due to fast charging and limiting the
power demand peak for a system power supply is required.
As a method therefor, a technique in which each of a plurality of devices
5 including a power generation device, such as a solar power generation device, or a
storage device, such as a fixed storage battery, in addition to the system power supply are
used in combination is known.
[0005]
In relation to the above, PTL 1 (W020111162025) discloses a technique relating
10 to a DC power distribution system. The DC power distribution system described in
PTL 1 includes a DC power distribution system, a first power conversion device, a
second power conversion device, and a third power conversion device. The DC power
distribution system supplies DC power to a load device. The first power conversion
device performs voltage conversion of generated power of a solar power generation
15 device and supplies power to the DC power distribution system. The second power
conversion device performs voltage conversion between a first power storage device
always connected to the DC power distribution system and the DC power distribution
system, and supplies power from one side to the other side. The third power conversion
device performs power conversion between an AC system and the DC power distribution
20 system, and supplies power from one side to the other side. The DC power distribution
system includes an operation mode setting unit and an operation control unit. The
operation mode setting unit determines an operation mode according to operation mode
determination information for setting an operation mode of the DC power distribution
system. The operation control unit sets a first control parameter for the second power
25 conversion device and a second control parameter for the third power conversion device
3
according to the operation mode set by the operation mode setting unit. The second
power conversion device performs control of a power supply direction, operation start,
and operation stop according to the voltage of the DC power distribution system and the
first control parameter. The third power conversion device performs control of a power
5 supply direction, operation start, and operation stop according to the voltage of the DC
power distribution system and the second control parameter.
[0006]
In the DC power distribution system described in PTL 1, first, a storage device
of a charging facility is charged with power supplied from a plurality of power supply
10 devices, and then, power charged in the storage device is discharged to charge the electric
vehicle. For this end, it is necessary to appropriately control the timing at which the
storage device is charged or discharged, the timing at which a plurality of power supply
devices, such as a system power supply or a power generation device, supply power to a
storage battery, or the like.
15
Citation List
Patent Literature
[0007]
[PTL 11 W020111162025
20
Summary of Invention
[OOOS]
The invention provides a fast charging facility for an electric vehicle which has a
simple configuration and allows flexible operation while a power generation device and a
25 storage device are combined with a system power supply, and an energy management
method for the charging facility.
[0009]
Other objects and novel features will become apparent from the description of
this specification and the accompanying drawings.
5 [OOl 01
According to one embodiment, a charging facility transforms power supplied
from a plurality of power supply devices and a storage device with power converters,
collects power in a DC bus, and then, uses power to charge an electric vehicle. In an
energy management method for a charging facility, each power converter operates under
10 independent automatic control according to a change in voltage in the DC bus.
[OO 1 11
According to one embodiment described above, an upper-level control unit
which collectively controls a plurality of power supply sources is not required, a plurality
of power supply devices can be combined with a simple configuration achieved by
15 merely connecting respective output terminals to the DC bus. In addition, the entire
charging facility can be operated flexibly.
Brief Description of Drawings
[0012]
20 FIG. 1 is a block circuit diagram showing a configuration example of a charging
facility according to an embodiment of the invention.
FIG. 2 is a graph showing an example of an energy management method for a
charging facility according to an embodiment of the invention.
FIG. 3 is a graph showing another example of an energy management method for
25 a charging facility according to an embodiment of the invention.
Description of Embodiments
[00 131
A mode for carrying out a charging facility and an energy management method
5 for a charging facility according to the invention will be described below referring to the
accompanying drawings.
[0014]
Embodiment
In an embodiment of the invention, one configuration example of a charging
10 facility in which a plurality of power converters are connected to a DC bus will be
described.
[0015]
Each of a plurality of power converters can be broadly classified into three types.
The power converters included in the first classification convert AC power supplied from
15 the outside, such as a system power supply, to DC power and supply the DC power to the
DC bus. The power converter included in the second classification supply power
generated by a power generation device, such as a solar power generation module, to the
DC bus. The power converters included in the third classification receive power from
the DC bus to charge the storage device. The power converters included in the third
20 classification also discharge power charged in the storage device and supply power to the
DC bus.
[0016]
The charging facility described herein is connected to a system power supply,
and has one power generation device and one storage device. However, the number of
25 devices is just an example, and is not intended to limit the invention. the details will be
6
described below, the presence or absence of connection to the system power supply, or
the number of connected power generation devices or storage devices is not particularly
limited, and in some cases, even if any one of the system power supply, the power
generation device, and the storage device is not linked, operation can be continued by a
5 combination of the remaining devices.
[00 171
FIG. 1 is a block circuit diagram showing a configuration example of the
charging facility according to the embodiment of the invention. The components of the
charging facility shown in FIG. 1 will be described.
10 [00 1 81
The charging facility shown in FIG. 1 includes a DC bus 1, an alternative current
(AC)/direct current (DC) conversion circuit 10 for a system power supply which receives
power from a system power supply 60, a solar power generation module 2 1, a DCIDC
conversion circuit 22 for a power generation device, a fixed storage battery 3 1, a DCIDC
1 5 conversion circuit 32 for a storage device, a rechargeable battery 4 1, and a DCIDC
conversion circuit 42 for a charging device for use in an electric vehicle.
[00 1 91
The ACIDC conversion circuit 10 for a system power supply which receives
power from the system power supply 60 and converts power to a DC voltage includes an
20 ACIDC converter control circuit 13 for a system power supply and an ACIDC converter
motor circuit 14 for a system power supply. The DCIDC conversion circuit 22 for a
power generation device includes a DCIDC converter control circuit 23 for a power
generation device and a DCIDC converter motor circuit 24 for a power generation device.
The DCIDC conversion circuit 22 for a power generation device and the solar power
25 generation module 21 may be collectively referred to as a power generation system.
7
The DCIDC conversion circuit 32 for a storage device includes a DCIDC converter
control circuit 33 for a storage device and a DCIDC converter motor circuit 34 for a
storage device. The fixed storage battery 3 1 includes a storage battery cell 35 and a
storage battery state monitoring device 36. The DCIDC conversion circuit 32 for a
5 storage device and the fixed storage battery 3 1 may be collectively referred to as a
storage system. The DCIDC conversion circuit 42 for a charging device includes a
DCIDC converter control circuit 43 for a charging device and a DCIDC converter motor
circuit 44 for a charging device. The DCIDC conversion circuit 42 for a charging
device and the rechargeable battery 41 may be collectively referred to as a charging
10 system. The motor circuit of each conversion circuit functions as a DC power
generation device which generates DC power.
[0020]
FIG. 1 also shows an electric vehicle 50, an on-board charging circuit 5 1, an
on-board rechargeable battery 52, and a system power supply 60. The on-board
15 charging circuit 5 1 and the on-board rechargeable battery 52 are included in the electric
vehicle 50.
[002 11
Though not shown in FIG. 1, the DC bus 1 includes a positive voltage bus to
which a positive voltage is applied, and a negative voltage bus to which a negative
20 voltage is applied. This configuration is just an example, and for example, a ground
may be used instead of the negative bus. The solar power generation module 21 is just
an example, and for example, a wind power generation module may be used instead.
[0022]
The functions of the components of the charging facility shown in FIG. 1 will be
25 described. Power received from the system power supply 60 is converted from an AC
8
voltage to a DC voltage by the ACIDC conversion circuit 10 for a system power supply,
and is supplied to the DC bus 1.
[0023]
The power generation system transforms (DCIDC conversion) power generated
5 by the solar power generation module 21 with the DCIDC conversion circuit 22 for a
power generation device, and supplies power to the DC bus 1.
[0024]
In regard to the storage system, charging power is supplied from the DC bus 1 to
the fixed storage battery 3 1 by the DCIDC conversion circuit 32 for a storage device, and
10 discharging power is supplied from the fixed storage battery 3 1 to the DC bus 1.
[0025]
In regard to the charging system, power requested by the on-board charging
circuit 5 1 is supplied from the DC bus 1 according to the remaining amount of the
on-board rechargeable battery 52 of the electric vehicle 50, thereby charging the
15 on-board rechargeable battery 52.
[0026]
The operation of the charging facility according to the embodiment of the
invention, that is, the energy management method for a charging facility according to the
embodiment of the invention will be described in more detail.
20 [0027]
The charging facility and the energy management method for a charging facility
according to the embodiment of the invention have the following three features. The
first feature is that peak cutting of received power from the system power supply 60 can
be performed without limiting charging power to the electric vehicle 50. Peak cutting
25 of received power is performed, whereby it is possible to reduce a basic charge of
9
electricity charges. The second feature is that the most of renewable energy, such as
power by solar power generation, is usable. The third feature is that power loss in the
power converters can be reduced.
[0028]
5 Accordingly, in the embodiment of the invention, charging of the on-board
rechargeable battery 52 is performed with the following priority. That is, first, power
supplied from the power generation system is used. If power supplied from the power
generation system is insufficient, power supplied from the system power supply 60 is
additionally used. In order to realize peak cutting of system received power, an upper
10 limit value is set for power received from the system power supply 60. For this reason,
if power supplied from the power generation system and the system power supply 60 is
yet insufficient, power supplied by discharging of the storage system is additionally used.
[0029]
In the embodiment of the invention, charging of the storage system is performed
15 using the following priority. That is, in a case where the remaining amount of charge of
the fixed storage battery 3 1 has some margin, charging of the fixed storage battery 3 1 is
performed only using power supplied from the power generation system. In a case
where the remaining amount of charge of the fixed storage battery 3 1 is smaller than a
predetermined reference value, charging of the fixed storage battery 3 1 is performed in a
20 short period of time using power supplied from the system power supply 60 in
combination with power supplied from the power generation system.
[003 01
The above control is performed by the respective power converters of the system
power supply 60, the power generation system, the storage system, and the charging
25 system individually, that is, independently from other power converters. Specifically,
10
for example, the ACIDC converter control circuit 13 for a system power supply monitors
the voltage of the DC bus 1, and the ACIDC converter control circuit 13 for a system
power supply controls the operation of the ACIDC converter motor circuit 14 for a
system power supply based on the result of monitoring, whereby the operation of the
5 ACIDC conversion circuit 10 for a system power supply connected to the system power
supply 60 is performed. At this time, control which is performed by the ACIDC
converter control circuit 13 for a system power supply has no relation to the power
generation system, the storage system, and the charging system. The same applies to
the operation of the power generation system, the storage system, and the charging
10 system.
[003 11
In other words, the charging facility according to the invention collects power
supplied from the ACIDC conversion circuit 10 for a system power supply, the power
generation system, and the storage system in the DC bus 1 in the form of DC power, and
15 charges the on-board rechargeable battery 52 of the electric vehicle 50 with DC power
collected in the DC bus 1. In the charging facility according to the invention,
controlling fixing the DC voltage in the DC bus 1 is not performed, and fluctuation of the
DC voltage in the DC bus 1 is used as a trigger on which the ACIDC conversion circuit
10 for a system power supply, the power generation system, the storage system, and the
20 charging system perform automatic control individually.
[0032]
An example of the overall operation of the charging facility shown in FIG. 1 will
be described referring to FIG. 2. FIG. 2 is a graph showing an example of the energy
management method for a charging facility according to the embodiment of the
25 invention.
FIG. 2 includes four graphs in total of a first graph (A) to a fourth graph (D).
In each of the first graph (A) to the fourth graph (D), the vertical axis indicates the
voltage of the DC bus 1, and the horizontal axis indicates output power of the DC bus 1.
5 [0034]
The first graph (A) indicates the relationship between power supplied from the
ACIDC conversion circuit 10 for a system power supply to the DC bus 1 and the voltage
of the DC bus 1. The second graph (B) indicates the relationship between power
supplied from the DCIDC conversion circuit 22 for a power generation device to the DC
10 bus 1 and the voltage of the DC bus 1. The third graph (C) indicates the relationship
between power supplied from the DCIDC conversion circuit 32 for a storage device to
the DC bus 1 and the voltage of the DC bus 1. The fourth graph (D) indicates the
relationship between a load applied from the DCIDC conversion circuit 42 for a charging
device to the DC bus 1 to the voltage of the DC bus 1.
15 [003 51
In the vertical axis of the graph shown in FIG. 2, P1 is maximum output power
determined by the rating of the DCIDC conversion circuit 22 for a power generation
device, and P2 is an upper limit set value of power received from the ACIDC conversion
circuit 10 for a system power supply.
20 [003 61
In the horizontal axis of the graph shown in FIG. 2, VA is a set voltage for a
system power supply, VB 1 is a first set voltage for a power generation device, VB2 is a
second set voltage for a power generation device, and VC is a set voltage for a storage
device. The set voltage VA for a system power supply is set in the ACIDC converter
25 control circuit 13 for a system power supply of the ACIDC conversion circuit 10 for a
12
system power supply. The first set voltage VB 1 for a power generation device and the
second set voltage VB2 for a power generation device are set in the DCIDC converter
control circuit 23 for a power generation device of the power generation system. The
set voltage VC for a storage device is set in the DCIDC converter control circuit 33 for a
5 storage device of the storage system. In the example of FIG. 2, the set voltage VC for a
storage device is set to be lower than the set voltage VA for a system power supply, the
set voltage VA for a system power supply is set to be lower than the second set voltage
VB2 for a power generation device, and the second set voltage VB2 for a power
generation device is set to be lower than the first set voltage VB 1 for a power generation
10 device.
[003 71
Specifically, for example, in the ACIDC conversion circuit 10 for a system
power supply, the ACIDC converter control circuit 13 for a system power supply
continuously monitors the voltage of the DC bus 1, and if the voltage of the DC bus 1
15 exceeds the set voltage VA for a system power supply, the ACIDC converter control
circuit 13 for a system power supply controls the ACIDC converter motor circuit 14 for a
system power supply and stops power supply from the ACIDC conversion circuit 10 for a
system power supply to the DC bus 1. On the contrary, if the voltage of the DC bus 1
falls below the set voltage VA for a system power supply, the ACIDC converter control
20 circuit 13 for a system power supply controls the ACIDC converter motor circuit 14 for a
system power supply and supplies power from the system power supply 60 to the DC bus
1.
[003 81
Similarly, in the power generation system, the DCIDC converter control circuit
25 23 for a power generation device continuously monitors the voltage of the DC bus 1, and
13
if the voltage of the DC bus 1 exceeds the first set voltage VB1 for a power generation
device, the DCIDC converter control circuit 23 for a power generation device controlling
stopping power supply to the DC bus 1 of the DCIDC converter motor circuit 24 for a
power generation device. On the contrary, if the voltage of the DC bus 1 falls below the
5 first set voltage VB1 for a power generation device, the DCIDC converter control circuit
23 for a power generation device controlling starting of the operation of the DCIDC
converter motor circuit 24 for a power generation device. When the voltage of the DC
bus 1 decreases from VB1, power supplied from the power generation system to the DC
bus 1 increases, and maximum generated power is supplied at a voltage equal to or lower
10 than VB2. In the storage system, the DCIDC converter control circuit 33 for a storage
device continuously monitors the voltage of the DC bus 1, and if the voltage of the DC
bus 1 exceeds the set voltage VC for a storage device, the DCIDC converter control
circuit 33 for a storage device controlling stopping of the power supply to the DC bus 1
of the DCIDC converter motor circuit 34 for a storage device. On the contrary, if the
15 voltage of the DC bus 1 falls below the set voltage VC for a storage device, the DCIDC
converter control circuit 33 for a storage device controlling starting of the discharging
operation of the DCIDC converter motor circuit 34 for a storage device.
[003 91
In the example of FIG. 2, first, the charging facility is activated from a state
20 where the voltage of the DC bus 1 is zero as an initial condition. From this state, the
ACIDC conversion circuit 10 for a system power supply starts to operate, and increases
the voltage of the DC bus 1 to be stabilized at the set voltage VA for a system power
supply. Thereafter, the power generation system and the storage system start to operate.
In a case where the amount of charge of the fixed storage battery 3 1 reaches an upper
25 limit, the voltage of the DC bus 1 increases with generated power of the power
14
generation system, and if the voltage of the DC bus 1 exceeds the first set voltage VB 1
for a power generation device, the power generation system stops power supply to the
DC bus 1. That is, in a state where the voltage of the DC bus 1 exceeds the first set
voltage VB 1 for a power generation device, since the first set voltage VB 1 for a power
5 generation device is set to be higher than the set voltage VA for a system power supply
and the set voltage VC for a storage device, controlling stopping of the entire power
supply to the DC bus 1 is performed.
[0040]
Next, the on-board rechargeable battery 52 of the electric vehicle 50 is
10 connected to the rechargeable battery 4 1 through the on-board charging circuit 5 1, and if
charging of the fixed storage battery 3 1 starts, a load applied to the DC bus 1 increases,
and when the load increases, the voltage of the DC bus 1 decreases.
[004 11
If the voltage of the DC bus 1 falls below the first set voltage VB 1 for a power
15 generation device, the DCIDC converter control circuit 23 for a power generation device
which monitors the voltage of the DC bus 1 detects this state, and performs control such
that the DCIDC converter motor circuit 24 for a power generation device starts to
operate.
[0042]
20 If the operation starts, the DCIDC converter motor circuit 24 for a power
generation device receives DC power generated by solar power generation of the solar
power generation module 21, converts the DC voltage of power, and supplies power to
the DC bus 1. Since the presence or absence of supply or the supply amount of
generated power to the DC bus 1 is determined by the DCIDC conversion circuit 22 for a
25 power generation device based on the voltage of the DC bus 1, the solar power
15
generation module 21 may continuously continue solar power generation without
particular control.
[0043]
Hereinafter, until the voltage of the DC bus 1 reaches the set voltage VA for a
5 system power supply, charging of the on-board rechargeable battery 52 is performed with
power supplied from the power generation system to the DC bus 1.
[0044]
Generated power supplied from the power generation system to the DC bus 1
increases when the voltage of the DC bus 1 decreases. Generated power of the power
10 generation system reaches maximum generated power of the power generation device
when the voltage of the DC bus 1 decreases and reaches the second set voltage VB2 for a
power generation device.
[0045]
If the voltage of the DC bus 1 decreases and reaches the set voltage VA for a
15 system power supply, the ACIDC converter control circuit 13 for a system power supply
which monitors the voltage of the DC bus 1 detects this state, and the ACIDC converter
motor circuit 14 for a system power supply starts power supply to the DC bus 1.
[0046]
The ACIDC converter motor circuit 14 for a system power supply receives AC
20 power of a system from the system power supply 60. The ACIDC converter motor
circuit 14 for a system power supply converts input AC power to DC power and supplies
DC power to the DC bus 1.
[0047]
Hereinafter, until the voltage of the DC bus 1 reaches the set voltage VC for a
25 storage device, charging of the on-board rechargeable battery 52 is performed with the
16
total sum of power supplied from the power generation system and the ACIDC
conversion circuit 10 for a system power supply to the DC bus 1.
[0048]
Power supplied from the ACIDC conversion circuit 10 for a system power
5 supply to the DC bus 1 increases when the voltage of the DC bus 1 decreases. In this
example, when power output from the ACIDC conversion circuit 10 for a system power
supply reaches the maximum power P2 which is an upper limit set value of received
power, a voltage that the voltage of the DC bus 1 reaches is set in the DCIDC converter
control circuit 33 for a storage device as the set voltage VC for a storage device. In
10 other words, the set voltage VC for a storage device is set such that output power from
the ACIDC conversion circuit 10 for a system power supply reaches the maximum power
P2, and the storage system starts power supply to the DC bus 1.
[0049]
If the voltage of the DC bus 1 decreases and reaches the set voltage VC for a
15 storage device, the DCIDC converter control circuit 33 for a storage device which
monitors the voltage of the DC bus 1 detects this state, and performs control such that the
DCIDC converter motor circuit 34 for a storage device starts the discharging operation.
[0050]
If the discharging operation starts, the DCIDC converter motor circuit 34 for a
20 storage device receives DC power charged in advance in the fixed storage battery 3 1,
changes the voltage of DC power, and supplies DC power to the DC bus 1. That is, DC
power discharged from the fixed storage battery 3 1 is supplied to the DC bus 1 through
the DCIDC converter motor circuit 34 for a storage device.
[005 11
Hereinafter, while the voltage of the DC bus 1 is lower than the set voltage VC
17
for a storage device, charging of the on-board rechargeable battery 52 is performed with
the total sum of the maximum power P1 which can be supplied from the power
generation system, the maximum power P2 which can be supplied from the ACIDC
conversion circuit 10 for a system power supply, and discharging power supplied from
5 the storage system.
[0052]
The set voltage VA for a system power supply, the first set voltage VB 1 for a
power generation device, the second set voltage VB2 for a power generation device, and
the set voltage VC for a storage device, the inclination of the graph representing the
10 relationship between power and the voltage of the DC bus 1 set in each of the ACIDC
conversion circuit 10 for a system power supply, the power generation system, and the
storage system, and the like can be adjusted within a predetermined range in the ACIDC
converter control circuit 13 for a system power supply, the DCIDC converter control
circuit 23 for a power generation device, the DCIDC converter control circuit 33 for a
15 storage device, and the like. The adjustment is appropriately performed, whereby it is
possible to freely determine the priority of the respective power converters which supply
power to the load applied to the DC bus 1.
[0053]
A charging operation of the fixed storage battery 3 1 in the storage system will be
20 described. While the voltage of the DC bus 1 has a value higher than the set voltage VC
for a storage device, that is, while the fixed storage battery 3 1 is not discharging,
charging of the fixed storage battery 3 1 can be performed in parallel with charging of the
on-board rechargeable battery 52.
[0054]
Charging of the fixed storage battery 3 1 can be performed in two operation
18
modes. First, in a case where the remaining amount of charge of the fixed storage
battery 3 1 is equal to or greater than a predetermined reference amount of charge set in
advance, for example, equal to or greater than 50%, charging is performed only with
power supplied from the power generation system without using power of the ACIDC
5 conversion circuit 10 for a system power supply. The determination is performed by the
storage battery state monitoring device 36 monitoring the remaining amount of charge of
the storage battery cell 35.
[005 51
Next, in a case where it is determined that the remaining amount of charge of the
10 fixed storage battery 3 1 is smaller than the reference amount of charge, for example, less
than 50%, charging is performed in a short period of time using power supplied from the
ACIDC conversion circuit 10 for a system power supply as well as power supplied from
the power generation system. At this time, power supplied from the system power
supply 60 is equal to or less than the upper limit set value of received power.
15 [0056]
In a case where the amount of charge of the fixed storage battery 3 1 reaches the
upper limit value and where the voltage of the DC bus 1 is equal to or higher than the set
voltage VC for a storage device, the DCIDC converter control circuit 33 for a storage
device controlling stopping of the power supply to both of the fixed storage battery 3 1
20 and the DC bus 1 of the DCIDC converter motor circuit 34 for a storage device.
[0057]
Another example of the overall operation of the charging facility shown in FIG.
1 will be described referring to FIG. 3. FIG. 3 is a graph showing another example of
the energy management method for a charging facility according to the embodiment of
25 the invention.
The graph shown in FIG. 3 includes a first graph (A) and a second graph (B).
In each of the first graph (A) and the second graph (B), the horizontal axis indicates time,
and the vertical axis indicates power supply-side power.
5 [0059]
The first graph (A) indicates an example of variation with time in power
supplied from the DC bus 1 to the on-board rechargeable battery 52 of the electric
vehicle 50. The second graph (B) indicates an example of variation with time in power
supplied from the DC bus 1 to the fixed storage battery 3 1.
10 [0060]
In the horizontal axis of the graph shown in FIG. 3, a period from the time to to
the time t2 indicates a period during which the voltage of the DC bus 1 is higher than the
set voltage VA for a system power supply and equal to or lower than the first set voltage
VB 1 for a power generation device. A period from the time t2 to the time t3 indicates a
15 period during which the voltage of the DC bus 1 is higher than the set voltage VC for a
storage device and equal to or lower than the set voltage VA for a system power supply.
A period from the time t3 to the time t5 is a period during which the voltage of the DC
bus 1 is equal to or lower than the set voltage VC for a storage device. A period from
the time t5 to the time t7 is a period during which the voltage of the DC bus 1 is equal to
20 the set voltage VC for a storage device. A period from the time t7 to the time t8 is a
period during which the voltage of the DC bus 1 is equal to the set voltage VA for a
system power supply. A period from the time t8 to the time t9 is a period during which
the voltage of the DC bus 1 is equal to or higher than the set voltage VA for a system
power supply and equal to or lower than the first set voltage VB 1 for a power generation
25 device. The set voltage VA for a system power supply, the first set voltage VBl for a
20
power generation device, and the set voltage VC for a storage device are the same as
those in the description relating to FIG. 2.
[006 11
In the vertical axis of the graph shown in FIG. 3, power P1 indicates maximum
5 power which can be supplied from the power generation system. Power P2 indicates
the total sum of maximum power which can be supplied from the power generation
system and maximum power which can be supplied from the ACIDC conversion circuit
10 for a system power supply. Power P3 indicates the total sum of maximum power
which can be supplied from the power generation system, maximum power which can be
10 supplied from the ACIDC conversion circuit 10 for a system power supply, and
maximum power which can be supplied at the time of discharging the storage system.
The maximum power which can be supplied from each of the ACIDC conversion circuit
10 for a system power supply, the power generation system, and the storage system is the
same as that in the description relating to FIG. 2.
15 [0062]
In the example of FIG. 3, in the charging facility according to the embodiment of
the invention, the situation of the variation with time in power supply and demand of
each device will be described.
[0063]
20 First, from the time to to the time tl, charging of the electric vehicle 50 is not
performed, and the storage battery cell 35 is charged to an upper limit of capacity.
During this period, the voltage of the DC bus 1 is higher than the set voltage VA for a
system power supply and equal to or lower than the first set voltage VB 1 for a power
generation device.
25 [0064]
21
Next, at the time tl, charging of the electric vehicle 50 starts. Thereafter, at the
time t2, until the power supply-side power reaches the power P1, charging of the electric
vehicle 50 is performed with power supplied from the DCIDC conversion circuit 22 for a
power generation device to the DC bus 1 according to the voltage of the DC bus 1.
5 From the time tl to the time t2, the voltage of the DC bus 1 is higher than the set voltage
VA for a system power supply and equal to or lower than the first set voltage VB 1 for a
power generation device.
[0065]
Next, at the time t2, as described above, the supply-side power reaches the
10 power P1. Charging of the electric vehicle 50 continues and is performed by the
maximum generated power of the DCIDC conversion circuit 22 for a power generation
device and received power from the system power supply 60. The supply-side power
continues to increase and reaches power P2 at the time t3. From the time t2 to the time
t3 during which the supply-side power is equal to or greater than the power P1 and less
15 than the power P2, the voltage of the DC bus 1 is higher than the set voltage VC for a
storage device and equal to or lower than the set voltage VA for a system power supply.
[0066]
Next, at the time t3, as described above, the supply-side power reaches the
power P2. Charging of the electric vehicle 50 continues and is performed with the
20 maximum generated power of the DCIDC conversion circuit 22 for a power generation
device, the upper limit value of received power from the system power supply 60, and
discharging power of the DCIDC conversion circuit 32 for a storage device. At this
time, discharging power of the DCIDC conversion circuit 32 for a storage device is
determined according to the voltage of the DC bus 1. The supply-side power continues
25 to increase and reaches power P3 at the time t4. From the time t3 to the time t4 during
22
which the supply-side power is equal to or greater than the power P2 and less than the
power P3, the voltage of the DC bus 1 is equal to or lower than the set voltage VC for a
storage device.
[0067]
5 Next, at the time t4, as described above, the supply-side power reaches the
power P3. While charging of the electric vehicle 50 continues and is performed with
the maximum generated power of the DCIDC conversion circuit 22 for a power
generation device, the upper limit value of received power from the system power supply
60, and discharging power of the DCIDC conversion circuit 32 for a storage device, the
10 amount of charge of the electric vehicle 50 approaches a full charge state, charging power
is started to be restricted. Thereafter, at the time t5, the supply-side power reaches the
power P2. From the time t4 to the time t5 during which the supply-side power is equal
to or less than the power P3 and greater than the power P2, the voltage of the DC bus 1 is
equal to or lower than the set voltage VC for a storage device.
15 [0068]
Next, at the time t5, as described above, the supply-side power reaches the
power P2. While charging of the electric vehicle 50 continues, the amount of charge of
the electric vehicle 50 further approaches the full charge state, and charging power is
restricted. When the supply-side power is less than the power P2 and equal to or greater
20 than the power P 1, the DCIDC conversion circuit 32 for a storage device discharges, and
the amount of charge decreases, the electric vehicle 50 and the storage battery cell 35 are
charged with the maximum generated power of the DCIDC conversion circuit 22 for a
power generation device and received power from the system power supply 60.
Thereafter, at the time t6, charging of the electric vehicle 50 ends. From the time t5 to
25 the time t6 during which the supply-side power is less than the power P2, the voltage of
23
the DC bus 1 is equal to the set voltage VC for a storage device. Charging power of the
storage battery cell 35 is controlled by the DCIDC converter control circuit 33 for a
storage device which monitors the voltage of the DC bus 1 such that the voltage of the
DC bus 1 does not fall below the set voltage VC for a storage device.
5 [0069]
Next, at the time t6, as described above, charging of the electric vehicle 50 ends.
When the storage battery cell 35 is discharged and the amount of charge decreases, the
storage battery cell 35 is charged with the maximum generated power of the DCIDC
conversion circuit 22 for a power generation device and received power from the system
10 power supply 60. Charging power of the storage battery cell 35 is controlled by the
DCIDC converter control circuit 33 for a storage device which monitors the voltage of
the DC bus 1 such that the voltage of the DC bus 1 does not fall below the set voltage VC
for a storage device.
[0070]
15 Next, at the time t7, the amount of charge of the storage battery cell 35 reaches a
value set in advance. Thereafter, until the time t8 when the amount of charge of the
storage battery cell 35 approaches the full charge state, charging of the storage battery
cell 35 is performed only with the maximum generated power of the DCIDC conversion
circuit 22 for a power generation device. From the time t7 to the time t8, the voltage of
20 the DC bus 1 is equal to the set voltage VA for a system power supply.
[007 11
Next, at the time t8, if the amount of charge of the storage battery cell 35
approaches the full charge state, the DCIDC conversion circuit 32 for storage device
starts to restrict charging power. For this reason, the voltage of the DC bus 1 increases,
25 and power supply from the DCIDC conversion circuit 22 for a power generation device is
24
restricted. Thereafter, at the time t9, while the amount of charge of the storage battery
cell 35 reaches the full charge state, the voltage of the DC bus 1 is higher than the set
voltage VA for a system power supply and equal to or lower than the first set voltage
VB 1 for a power generation device.
5 [0072]
The charging facility and the energy management method for a charging facility
according to the embodiment of the invention described above have the following
features.
[0073]
10 First, each of the ACIDC conversion circuit 10 for a system power supply, the
DCIDC conversion circuit 22 for a power generation device, and the DCIDC conversion
circuit 32 for a storage device autonomously performs an independent operation under
automatic control only based on the voltage fluctuating in the DC bus 1. Accordingly,
an upper-level control device which manages the entire charging facility is not required,
15 and the configuration as the whole of the charging facility is simplified.
[0074]
Furthermore, even if a part of power converters fails, operation with the
remaining power converters which are operating normally can be continued, and it is
easy to remove the failed power converters from the DC bus 1, to additionally connect
20 different power converters to the DC bus 1. That is, the charging facility according to
the invention allows very flexible operation.
[0075]
Although the invention made by the inventors has been concretely described
based on the embodiment, the present invention is not limited to the above-described
25 embodiment and can be variously modified without departing from the spirit or scope of
the invention. In addition, it is possible to freely combine the features described in the
embodiment as long as the technical contradiction does not occur.
[0076]
This application claims claims priority based on Japanese Patent Application No.
5 20 13 - 19449 1, the disclosure of which is incorporated herein by reference.
[0077]
In connection with the above, the following matters are disclosed.
[0078]
[l] An energy management method for a charging facility including
10 detachably connecting an external rechargeable battery to a charging circuit;
supplying DC power to a DC bus; and
charging the external rechargeable battery with the DC power supplied to the
DC bus;
wherein the supplying of the DC power includes
15 generating the DC power with a plurality of power converters,
monitoring the DC voltage in the DC bus in each power converter, and
controlling the operation of each power converter based on the DC voltage
monitored by each power converter independently from the remaining power converters
of the plurality of power converters; and
20 the charging of the external rechargeable battery includes
converting the DC power supplied to the DC bus to DC power for charging by a
DCIDC converter motor circuit for a charging device,
monitoring the DC voltage in the DC bus, and
controlling the operation of the DCIDC converter motor circuit for a charging
25 device based on a comparison result of the monitored DC voltage and a predetermined
set voltage.
[0079]
[2] The energy management method for a charging facility described in [I],
wherein the generating of the DC power includes
generating DC power with a power generation module, and
converting the generated DC power to the DC power by a DCIDC converter
motor circuit for a power generation device; and
the independently controlling includes
controlling the operation of the DCIDC converter motor circuit for a power
10 generation device according to the result of monitoring.
[OOSO]
[3] The energy management method for a charging facility described in [l] or [2], the
energy management method further including
receiving DC power from the DC bus and converting the received DC power to
15 the DC power to charge a storage battery,
wherein the generating of the DC power includes
discharging DC power charged in advance in the storage battery, and
converting the discharged DC power to the DC power and supplying the DC
power to the DC bus by a DCIDC converter motor circuit for a storage device; and
20 the independently controlling includes
controlling power supply to the DC bus or the storage battery of the DCIDC
converter motor circuit for a storage device according to the result of monitoring.
[0081]
[4] The energy management method for a charging facility described in [2],
25 wherein the independently controlling includes
27
starting supply of the DC power to the DC bus of the power generation module
if the monitored DC voltage is equal to or lower than a predetermined set voltage for a
power generation device, and
stopping supply of the DC power to the DC bus of the power generation module
5 if the monitored DC voltage is equal to or higher than the set voltage for a power
generation device.
[0082]
[5] The energy management method for a charging facility described in [3],
wherein the independently controlling includes
10 starting supply of the DC power to the DC bus of the DCIDC converter motor
circuit for a storage device if the monitored DC voltage is equal to or lower than a
predetermined set voltage for a storage device,
starting supply of the DC power to the storage battery of the DCIDC converter
motor circuit for a storage device if the monitored DC voltage is equal to or higher than
15 the set voltage for a system power supply,
starting supply of the DC power to the storage battery of the DCIDC converter
motor circuit for a storage device if the monitored DC voltage is equal to or higher than
the set voltage for a storage device and equal to or lower than the set voltage for a system
power supply and if the monitored remaining amount of charge is smaller than a
20 predetermined reference amount of charge, and
stopping power supply to both of the storage battery and the DC bus of the
DCIDC converter motor circuit for a storage device if the monitored DC voltage is equal
to or higher than the set voltage for a storage device and equal to or lower than the set
voltage for a system power supply and if the monitored remaining amount of charge is
25 greater than a predetermined reference amount of charge.
[6] The energy management method for a charging facility described in [5],
wherein the set voltage for a storage device is lower than the set voltage for a
system power supply, and
5 the set voltage for a system power supply is lower than the set voltage for a
power generation device.
[0084]
[7] The energy management method for a charging facility described in [2] or [4],
wherein the generating of power includes
performing solar power generation or performing wind power generation.
29
CLAIMS
1. A charging facility comprising:
a DC bus;
a plurality of power converters which supply DC power to the DC bus; and
5 a charging device which charges a detachably connected external rechargeable
battery with the DC power supplied to the DC bus, wherein
each of the plurality of power converters comprises:
a DC power generation unit which generates the DC power; and
a power control unit which monitors a DC voltage in the DC bus and controls
10 the operation of the DC power generation unit based on the monitored DC voltage
independently from other power converters, and
the charging device comprises:
a DCIDC converter motor circuit which converts the DC power supplied to the
DC bus to DC power for charging; and
15 a charging control unit which monitors a DC voltage in the DC bus and controls
the operation of the DCIDC converter motor circuit based on the comparison result of the
monitored DC voltage and a predetermined set voltage.
2. The charging facility according to claim 1, wherein
at least one of the plurality of power converters comprises:
a system power supply conversion circuit which converts AC power received
from a system to DC power and supplies the DC power to the DC bus, and
the system power supply conversion circuit comprises:
an ACIDC converter motor circuit for a system power supply which functions as
25 the DC power generation unit and is configured to convert the AC power to the DC
30
power and supply the DC power to the DC bus; and
a system power supply control unit which functions as the power control unit
and is configured to monitor a DC voltage in the DC bus and control the operation of the
ACIDC converter motor circuit for a system power supply according to the monitored
5 DC voltage.
3. The charging facility according to claim 1 or 2, wherein
at least one of the plurality of power converters comprises:
a power generation system which supplies DC power generated by power
10 generation to the DC bus, and
the power generation system comprises:
a power generation module which generates DC power by power generation;
a DCIDC converter motor circuit for a power generation device which functions
as the DC power generation unit and is configured to convert the generated DC power to
15 the DC power and supply the DC power to the DC bus; and
a power generation device control unit which hnctions as the power control unit
and is configured to monitor a DC voltage in the DC bus and control the operation of the
DCIDC converter motor circuit for a power generation device according to the monitored
DC voltage.
20
4. The charging facility according to any one of claims 1 to 3, wherein
at least one of the plurality of power converters comprises:
a storage system which supplies DC power discharged from a storage battery
charged in advance to the DC bus, and
25 the storage system comprises:
31
the storage battery;
a DCIDC converter motor circuit for a storage device which hnctions as the DC
power generation unit and is configured to convert DC power discharged from the
storage battery to different DC power and supply the DC power to the DC bus at the time
5 of discharging the storage battery, and is configured to receive DC power from the DC
bus, to convert the DC power to different DC power, and to charge the storage battery
with the DC power at the time of charging the storage battery; and
a storage device control unit which functions as the control unit and is
configured to monitor a DC voltage in the DC bus and a remaining amount of charge of
10 the storage battery and to control the operation of the DCIDC converter motor circuit for
a storage device according to the result of monitoring.
5. The charging facility according to claim 2, wherein
the system power supply control unit controls starting supply of the DC power
15 to the DC bus by the ACIDC converter motor circuit for a system power supply if the DC
voltage monitored by the system power supply control unit is equal to or lower than a
predetermined set voltage for a system power supply and controls stopping supply of the
DC power to the DC bus by the ACIDC converter motor circuit for a system power
supply if the monitored DC voltage is equal to or higher than the set voltage for a system
20 power supply.
6. The charging facility according to claim 3, wherein
the power generation device control unit controls starting power supply to the
DC bus of the DCIDC converter motor circuit for a power generation device if the
25 monitored DC voltage is equal to or lower than a predetermined set voltage for a power
32
generation device and controls stopping power supply to the DC bus of the DCIDC
converter motor circuit for a power generation device if the monitored DC voltage is
equal to or higher than the set voltage for a power generation device.
7. The charging facility according to claim 4, wherein
the storage device control unit controls:
starting power supply to the DC bus of the DCIDC converter motor circuit for a
storage device if the monitored DC voltage is equal to or lower than a predetermined set
voltage for a storage device;
10 starting power supply to the storage battery of the DCIDC converter motor
circuit for a storage device if the monitored DC voltage is equal to or higher than the set
voltage for a storage device;
starting supply of the DC power to the storage battery of the DCIDC converter
motor circuit for a storage device if the monitored DC voltage is equal to or higher than
15 the set voltage for a storage device and equal to or lower than the set voltage for a system
power supply and if the monitored remaining amount of charge is smaller than a
predetermined reference amount of charge; and
stopping supply of DC power to both of the storage battery and the DC bus of
the DCIDC converter motor circuit for a storage device if the DC voltage monitored by
20 the storage device control unit is equal to or higher than the set voltage for a storage
device and equal to or lower than the set voltage for a system power supply and if the
monitored remaining amount of charge is greater than a predetermined reference amount
of charge.
8. The charging facility according to claim 7, wherein
33
the set voltage for a storage device is lower than the set voltage for a system
power supply, and
the set voltage for a system power supply is lower than the set voltage for a
power generation device.
5
9. The charging facility according to claim 3 or 6, wherein
the power generation module comprises
a solar power generation module or a wind power generation module.
10 10. An energy management method for a charging facility comprising the
steps of
detachably connecting an external rechargeable battery to a charging circuit;
supplying DC power to a DC bus; and
charging the external rechargeable battery with the DC power supplied to the
15 DC bus, wherein
the step of supplying of the DC power comprises the steps of
generating the DC power with each of a plurality of power converters;
monitoring the DC voltage in the DC bus in each power converter; and
controlling the operation of each power converter based on the DC voltage
20 monitored by each power converter independently from the remaining power converters
of the plurality of power converters, and
the step of charging of the external rechargeable battery comprises the steps of
converting the DC power supplied to the DC bus to DC power for charging by a
DCIDC converter motor circuit for a charging device;
25 monitoring the DC voltage in the DC bus; and
34
controlling the operation of the DCIDC converter motor circuit for a charging
device based on a comparison result of the monitored DC voltage and a predetermined
set voltage.
5 11. The energy management method for a charging facility according to claim
10, wherein
the step of generating of the DC power comprises the steps of
receiving AC power; and
converting the AC power to the DC power with an ACIDC converter motor
10 circuit for a system power supply, and
the step of independently controlling comprises the step of
controlling the operation of the ACIDC converter motor circuit for a system
power supply according to the monitored DC voltage.
15 12. The energy management method for a charging facility according to claim
10 or 1 1, wherein
the step of generating of the DC power comprises the steps of
generating DC power with a power generation module; and
converting the generated DC power to the DC power by a DCIDC converter
20 motor circuit for a power generation device, and
the step of independently controlling comprises the step of
controlling the operation of the DCIDC converter motor circuit for a power
generation device according to the result of monitoring.
25 13. The energy management method for a charging facility according to any
35
one of claims 10 to 12, the energy management method further comprising the step of
receiving DC power from the DC bus and converting the received DC power to
the DC power to charge a storage battery, wherein
the step of generating of the DC power comprises the steps of
discharging DC power charged in advance in the storage battery; and
converting the discharged DC power to the DC power and supplying the DC
power to the DC bus by a DCIDC converter motor circuit for a storage device, and
the step of independently controlling comprises the step of
controlling power supply to the DC bus or the storage battery of the DCIDC
10 converter motor circuit for a storage device according to the result of monitoring.
14. The energy management method for a charging facility according to claim
1 1, wherein
the step of independently controlling comprises the steps of
15 controlling starting power supply to the DC bus to the ACIDC converter motor
circuit for a system power supply if the monitored DC voltage is equal to or lower than a
predetermined set voltage for a system power supply; and
controlling stopping power supply to the DC bus of the ACIDC converter motor
circuit for a system power supply if the monitored DC voltage is equal to or higher than
20 the set voltage for a system power supply.
15. The energy management method for a charging facility according to claim
12, wherein
the step of independently controlling comprises the steps of
starting supply to the DC power to the DC bus of the power generation module
36
if the monitored DC voltage is equal to or lower than a predetermined set voltage for a
power generation device; and
stopping supply of the DC power to the DC bus of the power generation module
if the monitored DC voltage is equal to or higher than the set voltage for a power
5 generation device.