Field of the Invention
The present invention relates to an electric power
management system that includes a power conditioner through
which the electric power generated by a power generation
apparatus, e.g., a photovoltaic power generation apparatus,
is used in association with the electric power generated by
an electric power system of a commercial power source.
Background of the Invention
In recent years, the number of houses and offices
equipped with a photovoltaic power generation apparatus (or
a solar cell) tends to increase. The solar cell has power
generation characteristics of generating an increased amount
of electric power as the illuminance of sunlight grows
higher, generating a reduced amount of electric power as the
illuminance of sunlight becomes lower due to the rainy
weather or other causes and stopping power generation at the
nighttime when there is no sunlight. For that reason, there
are many cases where the power generation pattern is not
consistent with the power consumption pattern in houses or
other places. Further, it is often the case that the
generated power amount becomes excessively smaller than the
consumed power amount. Accordingly, even if a house is
equipped with a solar cell, the house is usually connected
to an electric power system of a commercial power source so
that, when the generated power amount is insufficient, the
deficient electric power can be inputted (supplied) or
bought from the commercial power source.
The electric power generated by the solar cell differs
in nature from the electric power of the commercial power
source. In light of this, the electric power generated by
the solar cell is converted, by a power conditioner
including an inverter and the like, to an electric power
having the same nature as that of the alternating current
power of the commercial power source and is used in
association with the electric power system of the commercial
power source. This makes it possible to use, in
combination, the electric power generated by the solar cell
in a house or other places and the electric power of the
commercial power source.
In other words, the power conditioner is a device for
converting the electric power generated by the solar cell so
as to be made consistent with the electric power of the
commercial power source in a voltage, a frequency and a
phase and consequently using the electric power generated by
the solar cell in association with the electric power of the
commercial power source. One example of the power
conditioner is described in Patent document 1.
The power conditioner described in Patent document 1
is connected to a commercial power source and a solar cell
for supplying electric power, and an electric appliance
consuming the electric power. The power conditioner is
configured such that the electric power generated by the
solar cell is supplied to the electric appliance in
association with the electric power of the commercial power
source through the use of an inverter. The electric power
of the commercial power source can also be supplied to the
electric appliance through a switching device formed of a
semiconductor. If the amount of the electric power
generated by the solar cell is enough to provide the
electric power consumed by the electric appliance, the
switching device is opened to supply only the electric power
generated by the solar cell to the electric appliance. On
the other hand, if the amount of the electric power
generated by the solar cell is insufficient, the switching
device is closed to supply the electric power generated by
the solar cell in association with the electric power of the
commercial power source to the electric appliance.
Patent document 1: Japanese Patent No. 2503402
In general, the user of a solar cell is highly
interested in the trend of the electric power generated by
the solar cell. Thus the user wishes to easily check out
the various electric power information including not only
the amount of the electric power generated by the solar cell
but also the amount of the electric power inputted
(supplied) from the commercial power source and the amount
of the electric power consumed by the electric appliance and
the like.
In view of this, it may be considerable to provide the
power conditioner to collect the amount of the electric
power generated by the solar cell and the amount of the
electric power consumed by the electric appliance and to
collect, from a power meter, the accurate amount of the
electric power inputted (supplied) from and outputted
(reversely supplied) to the commercial power source, so that
the user can check out the various kinds of electric power
information.
However, the power conditioner is usually installed in
an indoor region from the terms of the enhanced installation
environment and the user's convenience in operation, while
the power meter is installed in an outdoor region for the
purpose of meter reading. It is not easy for the power
conditioner installed in the indoor region to effectively
collect the amount of the electric power measured by the
power meter installed in the outdoor region.
Summary of the Invention
In view of the above, the present invention provides
an electric power management system capable of easily
performing, by using a power conditioner, a centralized
management of various kinds of information including the
information on the amount of electric power measured by a
power meter connected to an electric power system of a
commercial power source.
In accordance with an embodiment of the present
invention, there is provided an electric power management
system, including: a power meter connected to a power system
of a commercial power source; and a power conditioner
connected to the power meter, a power generating device and
an electric appliance. The power meter and the power
conditioner exchange power information through a
communications part at a side of the power meter.
In the electric power management system described
above, the power meter may be connected to the power system
of the commercial power source to acquire power information
from an electric power inputted from the power system and an
electric power outputted to the power system. Further, the
power conditioner may be configured to collect power
information of the power generating device; power
information of the electric appliance; and the power
information of the electric power inputted from the power
system and the power information of the electric power
outputted to the power system, which are acquired from the
power meter through the communications part at the side of
the power meter, and to manage the electric power inputted
from the power system and the electric power outputted to
the power system, based on the collected power information.
In general, the power meter is arranged outside a
house or a building and the power conditioner is arranged
inside the house or the building. This makes it difficult
for the power conditioner to acquire the power information
such as the amount of electric power measured by the power
meter.
With such configuration, the power meter and the power
conditioner can make communications with each other through
the communications part at the side of the power meter.
Through the communications with the power meter, the power
conditioner can easily acquire from the power meter the
power information on the voltage, current, electric power
amount, frequency and phase of the electric power inputted
from or outputted to the commercial power source, which is
measured by the power meter. As a result, the power
conditioner can accurately acquire the power information on
the electric power inputted from or outputted to the
commercial power source, which does not entail the loss
caused by outdoor wiring lines and coincides with the meter
reading value of a power company. This enables the electric
power management system to accurately and properly manage
the electric power.
In addition, the power information on the electric
power generated by the power generating devices, the power
information on the electric power consumed by the respective
electric appliances and the power information on the
electric power measured by the power meter are collected in
the power conditioner. It is therefore possible to
appropriately carry out the electric power management of the
entire power supply system based on the power information
stated above. As a result, it is possible for the power
conditioner to accurately perform the centralized power
management including the management of the input and output
of the electric power to and from the power system. This
makes it possible to increase the utility value of the
electric power management system.
Further, the electric power management system
described above may further include a display device for
acquiring the power information collected in the power
conditioner from the power conditioner through a
communications part at a side of the display device and
visually displaying the acquired power information on a
display unit.
With such configuration, the display device can
acquire the power information collected in the power
conditioner through the communications part at the side of
the display device and can visibly display the display
information generated from the acquired power information in
the form of an image such as a numerical number or a graph.
This makes it easy to check out the power information
collected in the power conditioner. Accordingly, it is
possible to enhance the utility value of the electric power
management system.
Further, the communications part at the side of the
display device may include a subordinate extension unit
provided in the power conditioner to transmit the power
information collected in the power conditioner and a
communications unit provided in the display device to
receive the power information transmitted from the
subordinate extension unit.
With such configuration, it is possible to easily
transfer the power information of the power conditioner to
the display device, by providing the subordinate extension
unit in the power conditioner and the communications unit in
the display device and enabling communications between the
subordinate extension unit and the communications unit.
Further, the" communications part at the side of the
power meter may include a first extension unit provided in
the power meter to transmit the power information acquired
from the power meter and a second extension unit provided in
the power conditioner to receive the power information
transmitted from the first extension unit.
With such configuration, it is possible for the first
extension unit of the power meter and the second extension
unit of the power conditioner to mutually transfer the power
information of the power meter and the power information of
the power conditioner, by providing the first extension unit
and the second extension unit and enabling communications
between the first extension unit and the second extension
unit.
Further, the second extension unit of the power
conditioner may serve as the subordinate extension unit of
the corresponding power conditioner.
With such configuration, the communications between
the power meter and the power conditioner and the
communications between the power conditioner and the display
device can be performed in the same communications method.
In other words, the communications methods of the first
communications part and the second communications part are
unified into a single method. This makes it possible to
simplify the structure of the subordinate extension unit of
the power conditioner included in the first communications
part and the second communications part. This also helps
reduce the effort required in installing communications
equipment.
Further, the power meter may further include a device
communicatively connected to a system server for managing
^he power system of the commercial power source and
configured to acquire the power information collected in the
power conditioner through the communications part at the
side of the power meter and transfer the acquired power
information to the system server.
With such configuration, the system server managing
the power system can acquire the power information of the
power conditioner and can estimate the power consumption
trend using the power management data contained in the power
information thus acquired. For example, if the system
server is allowed to manage the power system based on the
power consumption trend, it is possible to further stabilize
the electric power of the power system and to increase the
utility value of the electric power management system.
Further, the power conditioner may be configured to
acquire power information held by the system server through
the power meter and to manage the acquired power
information.
With such configuration, the power conditioner
acquires the power information of the system server from the
power meter and manages the power information together with
the electric power inputted from and outputted to the power
system. As a result, for example, if the power information
of the system server contains the information for
stabilization of the system, the power conditioner can
adjust the electric power inputted to and outputted from the
commercial power source, thereby stabilizing the power
system. If the power information of the system server
contains the billing information, it is possible to perform
the management of electric power according to the charged
fare.
Brief Description of the Drawings
The objects and features of the present invention will
become apparent from the following description of preferred
embodiments given in conjunction with the accompanying
drawings, in which:
Fig. 1 is a functional block diagram showing the
schematic configuration of a power supply system which
forms a part of an electric power management system
according to a first embodiment of the present invention;
Fig. 2 is a configuration view showing the specific
configuration of the electric power management system of
the first embodiment;
Figs. 3A and 3B are views schematically showing a
connection configuration that enables communications
between a power meter, a power conditioner and a display
device unit employed in the electric power management
system of the first embodiment;
Figs. 4A and 4B are views schematically showing a
connection configuration that enables communications
between a power meter, a power conditioner and a display
device unit employed in an electric power management system
according to a second embodiment;
Fig. 5 is a configuration view showing one example of
a subordinate extension unit of the power conditioner
employed in the electric power management systems of the
first and second embodiments;
Fig. 6 is a .view schematically showing one example of
the connection for communications between the power meter,
the power conditioner and the display device unit employed
in the electric power management systems of the first and
second embodiments; and
Fig. 7 is a view schematically showing another example
of the connection for communications between the power
meter, the power conditioner and the display device unit
employed in the electric power management systems of the
first and second embodiments.
Detailed Description of the Preferred Embodiments
Hereinafter, embodiments of the present invention will
be described with reference to the accompanying drawings
which form a part hereof. Throughout the drawings, like
reference numerals will be given to like parts, and
redundant description thereof will be omitted.
(First Embodiment)
An electric power management system in accordance with
a first embodiment of the present invention will be
described in detail. Fig. 1 is a functional block diagram
showing a schematic configuration of a power supply system
1 which forms a part of the electric power management
system.
As shown in Fig. 1, a house is provided with the power
supply system 1 for supplying an electric power to a variety
of home appliances (such as an illuminating device, an air
conditioner, an electrical device and an audiovisual
device). The power supply system 1 supplies the electric
power of a home-use commercial AC source (or a commercial
power source) 2 and further supplies the electric power from
a solar cell 3 generating electric power with the sunlight
to operate various kinds of appliances. The power supply
system 1 supplies the electric power to not only DC
appliances 5 operating with the DC power inputted from a DC
power supply but also an AC appliance 6 operating with the
AC power inputted from an AC power source 2. In the
following description, a single house will be taken as an
example of the building to which the present invention is
applied. However, it is not limited thereto. For example,
the present invention may also be applied to building or
collective housings such as an office, a shopping arcade and
a factory.
The power supply system 1 is provided with a power
conditioner 50 including a controller 7 and a DC
distribution board (in which a DC breaker is arranged) 8.
The power supply system 1 is further provided with a control
unit 9 and a relay unit 10 for controlling operations of the
DC appliances 5 installed in the house.
An AC distribution board 11 for dividing the AC power
is connected to the controller 7 through an AC power line
12. The controller 7 is connected to the commercial AC
power source 2 via the AC distribution board 11 and is
connected to the solar cell 3 via a DC power line 13. The
controller 7 receives AC power from the AC distribution
board 11 and receives DC power from the solar cell 3. The
controller 7 converts the AC power and the DC power to
specified DC power to be used as the source power of the
appliances. The controller 7 outputs the converted DC power
to the DC distribution board 8 through a DC power line 14 or
to a battery 16 through a DC power line 15 to thereby store
the DC power in the battery 16. Not only does the
controller 7 receive the AC power from the AC distribution
board 11 but also the controller 7 can convert the electric
power from the solar cell 3 or the battery 16 to an AC power
and supply the AC power to the AC distribution board 11.
The controller 7 exchanges data with the DC distribution
board 8 through a signal line 17. An illuminometer 42 for
measuring the illuminance of the light irradiated on the
solar cell 3 is connected to the controller 7. Illuminance
information as environmental information such as an
illuminance value is transmitted from the illuminometer 42
~o the controller 7.
The DC distribution board 8 is a kind of breaker for
the DC power. The DC distribution board 8 divides the DC
power inputted from the controller 7 and outputs the divided
DC power to the control unit 9 through a DC power line 18 or
to the relay unit 10 through a DC power line 19. The DC
distribution board 8 exchanges data with the control unit 9
through a signal line 20 or with the relay unit 10 through a
signal line 21.
In the power supply system 1, the power conditioner 50
for coordinating power management in the power supply system
1 is configured in such a fashion as to include the
controller 7 and the DC distribution board 8. The power
conditioner 50 is' provided with a memory device 50DB (see
Fig. 2) storing various kinds of information. In other
words, the power conditioner 50 is connected to the AC
distribution board 11, the solar cell 3, the battery 16 and
the DC appliances 5 through individual power lines. Based
on this, the power conditioner 50 is configured to measure
the power information on the AC power supplied or reversely
supplied (inputted or outputted) to or from the AC power
source 2 and to measure the power information (power
generation information) on the electric power generated by
the solar cell 3 and the power information on the DC power
consumed in the DC appliances 5.
Examples of the power information on the AC power
include a voltage, a current, an electric power amount, a
frequency and a phase. Examples of the power information on
the DC power include a voltage, a current and an electric
power amount. The power information selected from them is
measured in the power conditioner 50. In the power
conditioner 50, the power information on the AC power source
2 and the power information of the solar cell 3 and the DC
appliances 5 thus measured are collected in the memory
device 50DB as power-related information 50J (see Fig. 2).
A plurality of DC appliances 5 is connected to the
control unit 9. The DC appliances 5 are connected to the
control unit 9 through respective DC supply lines 22 through
which both DC power and data can be transmitted by using the
same wiring. Communications signals for transmitting data
with a high-frequency carrier wave are overlapped with the
DC power to be supplied to the DC appliances 5 and are
transmitted through the respective DC supply lines 22. For
example, both the electric power and the data are
transmitted to each of the DC appliances 5 by using a pair
of lines. The control unit 9 receives the DC power for the
DC appliances 5 through a DC power line 18 and determines
how to control which of the DC appliances 5 based on an
operation instruction obtained from the DC distribution
board 8 through a signal line 20. Then, the control unit 9
outputs the DC power and the operation instruction to the
designated DC appliances 5 through the corresponding DC
supply lines 22, thereby controlling the operations of the
DC appliances 5.
Switches 23 that are manipulated when the operations
of the DC appliances 5 are switched over are connected to
the control unit 9 through a DC supply line 22. In
addition, a sensor 24 for detecting radio waves transmitted
from, e.g., an infrared remote controller is connected to
the control unit 9 through the DC supply line 22.
Accordingly, the DC appliances 5 are controlled by
transmitting communications signals through the DC supply
lines 22 in response not only to the operation instruction
from the DC distribution board 8 but also to the
manipulation of the switches 23 and the detection in the
sensor 24.
Further, the control unit 9 can transfer the power
information on the electric power amounts consumed by the
respective DC appliances 5 and the like to the power
conditioner 50 (or the DC distribution board 8) through a
signal line 20. As a result, the power information of the
respective DC appliances 5 connected to the control unit 9
is collected in the power conditioner 50. Alternatively,
the DC appliances 5 connected to the control unit 9 through
the respective DC supply lines 22 can transfer the power
information on the electric power amounts detected by
themselves and the like to the power conditioner 50 through
the control unit 9 so that the information can be collected
in the memory device 5 0DB.
A plurality of DC appliances 5 is connected to the
relay unit 10 through individual DC power lines 25. The
relay unit 10 obtains the DC power for the DC appliances 5
through a DC power line 19, and determines which of the DC
appliances 5 is to be operated based on an operation
instruction obtained from the DC distribution board 8
through the signal line 21.
Further, the. relay unit 10 controls the operations of
the DC appliances 5 determined to be operated in such a way
that relays built therein turn on and off the supply of
powers through the DC power lines 25. A plurality of
switches 2 6 for manually operating the DC appliances 5 is
connected to the relay unit 10. The DC appliances 5 are
controlled by manually manipulating the switches 26 to cause
the relays to turn on and off the supply of powers to the DC
power lines 25. The relay unit 10 can transfer the power
information on the electric power amounts consumed by the
respective DC appliances 5 and the like to the power
conditioner 50 (or the DC distribution board 8) through the
signal line 21. As a result, the power information of the
respective DC appliances 5 connected to the relay unit 10 is
collected in the memory device 50DB of the power conditioner
50.
In the power conditioner 50, various kinds of power
information of the power supply system 1 such as the power
information measured by the power conditioner 50 itself and
the power information detected by the control unit 9 and the
relay unit 10 are collected in the memory device 50DB as
power-related information 50J. The power-related
information 50J can be utilized as power management data in
the power supply system 1. The power conditioner 50 can
generate estimated consumption information indicating the
current power consumption amount based on the power
management data obtainable from the power-related
information 50J.
DC sockets 27 installed in the house in the form of,
e.g., a wall socket or a floor socket, are connected to the
DC distribution board 8 through a DC power line 28. If the
plugs (not shown) of the DC appliances 5 are inserted into
the DC sockets 27, it is possible to directly supply the DC
power to the DC appliances 5.
A power meter 29 capable of remotely measuring the
amount of the power used by the commercial AC power source 2
is connected between the commercial AC power source 2 and
the AC distribution board 11. The power meter 29 is
equipped with not only a function of remotely measuring an
amount of power used by the commercial AC power source 2 but
also, e.g., a power line communications (PLC) function and a
wireless communications function. The power meter 2 9
transmits measurement results to an electric power company
or the like through power line communications or wireless
communications.
In the present embodiment, the communications between
the power meter 29 which transfers the measurement results
to the electric power company and the power company is
performed as follows. Communications is performed between
the power company and an electric pole through a well-known
communications line. Moreover, communications is performed
between the communications line and the power meter 2 9 by
virtue of power line communications in which a lead-in power
line 2A connected to a step-down transformer TR (see Fig. 2)
is used as a communications medium. The power meter 2 9 is
also connected to the power conditioner 50 via a first
communications part in such a way as to make communications
with each other.
A display device 43 for visually displaying the power-
related information 50J managed by the power conditioner 50
is connected to the AC distribution board 11 through a
second communications part. That is, in the present
embodiment, the power conditioner 50 transmits the power-
related information 50J to be displayed on the display
device 43. The display device 43 receives the power-related
information 50J transmitted from the power conditioner 50.
The power supply system 1 is provided with a network
system 30 that makes it possible to control various kinds of
home appliances through network communications. The network
system 30 includes a home server 31 that functions as a
control unit thereof. The home server 31 is connected to an
outdoor management server 32 through an external
communications network NT such as the Internet and is also
connected to home appliances 34 through a signal line 33.
The home server 31 is operated by the DC power supplied from
the DC distribution board 8 through a DC power line 35.
A control box 36 for managing the operations of
various kinds of home appliances controlled through network
communications is connected to the home server 31 through a
signal line 37. The control box 36 is connected to the
controller 7 and the DC distribution board 8 through a
signal line 17. The control box 36 is capable of directly
controlling the DC appliances 5 through a DC supply line 38.
A gas/tap water meter 39 capable of remotely measuring,
e.g., the amounts of gas and tap water used, is connected to
the control box 36. The control box 36 is connected to an
operation panel 40 of the network system 30. A monitoring
device 41 formed of, e.g., a door phone extension unit, a
sensor or a camera, is connected to the operation panel 40.
If an operation instruction to operate the various
kinds of home appliances is inputted through the external
communications network NT, the home server 31 notifies the
control box 36 of the operation instruction and operates the
control box 36 so that the home appliances can be operated
based on the operation instruction. Moreover, the home
server 31 can provide various kinds of information obtained
from the gas/tap water meter 39 to the management server 32
through the external communications network NT. If an
abnormality detected by the monitoring device 41 is notified
to the home server 31 through the operation panel 40, the
home server 31 provides the information on the detected
abnormality to the management server 32 through the external
communications network NT.
Next, the specific configuration of the electric power
management system in accordance with the present embodiment
will be described with reference to Fig. 2. Fig. 2 is a
configuration view specifically showing the configuration
of the electric power management system.
As shown in Fig. 2, the power supply system 1
installed in a house or other places is connected through
the power meter 29 to an electric power system of an AC
power source 2 managed by the electric power company. In
other words, a plurality of power meters 29 including the
ones not showing in Fig. 2 is connected to the power system
of the AC power source 2 through individual lead-in power
lines 2A extending from a step-down transformer TR. The
power meter 2 9 is provided with an extension unit 68 having
a function of making power line communications with a base
unit 66 installed on an electric pole. The base unit 66 on
the electric pole and the extension unit 68 of the power
meter 29 are connected to each other through a power signal
line 67 and a lead-in power line 2A with the step-down
transformer TR interposed therebetween. In other words, the
lead-in power line 2A transmits AC power between the power
system and the power meter 29 and serves as a communications
medium through which a power line communications signal is
transmitted between the base unit 66 and the extension unit
68 of the power meter 29.
The power company 60 has a dedicated communications
line 64 used in remotely reading the amount of power
measured by the power meter 29. The communications line 64
is similar in form to the wiring line of the power system of
the AC power source 2. The base unit 66 is communicatively
connected to the communications line 64 through a
communications line 65 and a media converter 63. In other
words, the base unit 66 enables communications signals to be
exchanged between the communications line 64 and the power
signal line 67 and converts the type of received signals
into the type of transmitted signals and vice versa. A
meter reading server (not shown) of the power company 60 is
communicatively connected to the communications line 64.
Thus, the meter reading server can perform a so-called
remote meter reading that acquires the amount of power (the
meter reading results) measured by the power meter 2 9
communicatively connected through the communications line 64
through communications and records the amount of power thus
acquired.
Further, the power company 60 has a system server 61
for managing the information on the AC power flowing through
the power system of a commercial power source. The system
server 61 is communicatively connected to the communications
line 64 through a communications line 62 and a media
converter 63. Accordingly, the system server 61 of the
power company 60 is communicatively connected to the power
meter 29, connected to the communications line 64, through
the communications line 64.
For example, the system server 61 collects and manages
the power information such as the power generation amounts
of a plurality of power plants held by the power company 60,
the power consumption amounts of the respective power
systems distinguished for respective areas, and the power
amounts reversely supplied from the solar cell 3 or the like
to the power systems. The system server 61 enables the
power company 60 to use the information in managing the
power systems of the commercial power source. In other
words, the power meter 29 communicatively connected to the
system server 61 can transmit the power information to the
system server 61 and can receive the power information from
the system server 61.
In the electric power management system of the present
embodiment, the power meter 29 and the power conditioner 50
are communicatively connected to each other via a
communications part at a side of the power meter
(hereinafter referred to as "first communications part").
Next, the first communications part communicatively
interconnecting the power meter 29 and the power conditioner
50 and the communications part at a side of the display
device (hereinafter referred to as "second communications
part.") communicatively interconnecting the power conditioner
50 and the display device 43 will be described with
reference to Figs. 3A and 3B. Figs. 3A and 3B are schematic
views showing a connection configuration that enables
communications between the power meter 2 9 and the power
conditioner 50 and between the power conditioner 50 and the
display device 43.
As shown in Figs. 3A and 3B, the power meter 29 is a
meter for measuring the current, voltage and power amount of
the single-phase three-wire AC power inputted and outputted
between the power meter 29 and the power system of the
commercial power source. Further, the power meter 29
includes a terminal block 80 connected to the power system
of the commercial power source and a terminal block 81
connected to the power conditioner 50 via an AC distribution
board 11. The terminal block 80 is provided with terminals
SI, S2 and S3 and the terminal block 81 is provided with
terminals LI, L2 and L3. The terminal SI and the terminal
LI are connected to each other. The terminal S2 and the
terminal L2 are connected to each other. The terminal S3
and the terminal L3 are connected to each other.
In the present embodiment, a single-phase AC power is
supplied to the terminals SI and S3. The terminal S2
becomes a neutral line. Thus, the power meter 29 is
provided with a current measuring unit 82 for measuring the
current flowing through the terminal SI, a current measuring
unit 83 for measuring the current flowing through the
terminal S3, a voltage measuring unit 84 for measuring the
voltage between the terminals SI and S2 and a voltage
measuring unit 85 for measuring the voltage between the
terminals S3 and S2. Signals indicating the current values
measured by the current measuring units 82 and 83 and
signals indicating the voltage values measured by the
voltage measuring units 84 and 85 are inputted to a control
circuit 86 so that the control circuit 86 can perform
calculation of a power amount or the like.
The control circuit 86 transmits a signal indicating
the calculated power amount to a display circuit 87 so that
the display circuit 87 can display the calculated power
amount. The display circuit 87 includes a display unit
capable of visually displaying information. The power
amount received from the control circuit 8 6 and other
information are displayed on the display unit in a visible
form such as numerical numbers.
The power meter 29 is provided with an extension unit
6 8 for making communications, through power lines connected
to the terminal block 80 and the terminal block 81, with
other units connected to the power lines.
The extension unit 68 is configured to perform power
line communications using the power lines as a
communications medium. The extension unit 68 includes: a
coupling circuit 92 that uses the power lines connected to
the terminals SI and S3 as the communications medium, the
coupling circuit 92 connected to the communications medium;
a transceiver circuit 93 for transmitting and receiving a
modulated signal to and from the coupling circuit 92; and a
power line communications processing circuit 94 for
transmitting and receiving communications signal information
to and from the transceiver circuit 93. A control circuit
86 is connected to the power line communications processing
circuit 94, so that signals through power line
communications are transmitted and received therebetween.
Accordingly, the extension unit 68 acquires a power
line communications signal, which is overlapped with the
electric power and received through the power lines (the
terminals SI and S3) , and transfers the acquired signal to
the control circuit 86. Furthermore, the extension unit 68
converts the signal outputted from the control circuit 8 6 to
a power line communications signal and transmits the power
line communications signal through the power lines (the
terminals SI and S3) by overlapping same with the electric
power. In order to efficiently overlap the power line
communications signal with the electric power, it is
preferred that the impedance of the power lines, i.e., the
impedance between the terminals SI and S3, in a
communications frequency band used for power line
communications is kept high.
Further, the power meter 2 9 is provided with a power
supply unit 91A for supplying the electric power required to
drive the control circuit 8 6 and so forth. The power supply
unit 91A is connected to the terminals SI and S3. The power
supply unit 91A converts the electric power inputted from
the terminals SI and S3 to the electric power required to
drive the control circuit 86 and so forth. In general, a
capacitor is connected to an input circuit of the power
supply unit 91A to prevent noises from leaking to the
outside. The capacitor serves to reduce the impedance of
the power lines connected to the input circuit of the power
supply unit 91A, i.e., the impedance within a communications
frequency band used for power line communications.
In the present embodiment, therefore, a matching
circuit 91M, i.e., a so-called impedance booster, for
avoiding reduction of the impedance of the power lines
within a power line communications frequency band is
provided between the power line and the input circuit of the
power supply unit 91A so that the power line communications
can be efficiently performed by the extension unit 68 of the
power meter 29. As a result, the power supply unit 91A can
be connected to the terminals SI and S3 while restraining
reduction of the impedance between the terminals SI and S3
within a power line communications frequency band.
The terminal block 81 of the power meter 2 9 is
connected to the AC distribution board 11 through the
terminals LI, L2 and L3. The AC distribution board 11 is
connected to the power conditioner 50 through a terminal Tl
corresponding to the terminal LI of the terminal block 81
and a terminal T3 corresponding to the terminal L3 of the
terminal block 81.
The power conditioner 50 converts the AC power
inputted from an AC terminal block 51 to DC power and
outputs the DC power to a DC terminal block 52. Moreover,
the power conditioner 50 has a function of converting the DC
power inputted from the DC terminal block 52 to AC power and
outputting the AC power to the AC terminal block 51. The AC
power flowing through the terminals Tl and T3 of the AC
terminal block 51 of the power conditioner 50 is inputted to
an inverter unit 53A after the current value thereof is
measured by an output current measuring unit 54 and the
voltage value thereof is measured by an output voltage
measuring unit 55.
The inverter unit 53A includes an inverter circuit 531
for performing AC-DC conversion or DC-AC conversion of the
electric power and a matching circuit 53M for restraining
reduction of the impedance between the terminals Tl and T3.
In order to reduce the impedance of the power lines
connected to the inverter circuit 531, the matching circuit
5 3M is arranged between the inverter circuit 531 and the
terminals Tl and T3. The inverter unit 53A is connected to
terminals P and N of the DC terminal block 52. The current
value of the DC power flowing through the DC terminal block
52 is measured by an input current measuring unit 56 and the
voltage value thereof is measured by an input voltage
measuring unit 57.
The current value measured by the output current
measuring unit 54, the voltage value measured by the output
voltage measuring unit 55, the current value measured by the
input current measuring unit 5 6 and the voltage value
measured by the input voltage measuring unit 57 are inputted
to a control circuit 58. The control circuit 58 controls
the DC-AC conversion or the AC-DC conversion of the electric
power performed in the power conditioner 50 by setting
various kinds of information on the power conversion with
respect to the inverter unit 53A.
The power conditioner 50 is provided with a
subordinate extension unit 70 for making communications,
through power lines connected to the AC terminal block 51,
with other units connected to the power lines. The
subordinate extension unit 70 is configured to perform power
line communications using the power lines as a
communications medium. The subordinate extension unit 70
has the same configuration as that of the extension unit 68
of the power meter 29.
More specifically, the subordinate extension unit 70
includes: a coupling circuit 73 that uses the power lines
connected to the terminals Tl and T3 as the communications
medium, the coupling circuit 73 connected to the
communications medium; a transceiver circuit 74 for
transmitting and receiving a modulated signal to and from
the coupling circuit 73; and a power line communications
processing circuit 75 for transmitting and receiving
communications signal information to and from the
transceiver circuit 74. A control circuit 58 is connected
to the power line communications processing circuit 75, so
that signals through power line communications are
transmitted and received therebetween.
Accordingly, the subordinate extension unit 70
acquires a power line communications signal, which is
overlapped with the electric power and received through the
power lines (the "terminals Tl and T3) , and transfers the
acquired signal to the control circuit 58. Furthermore, the
subordinate extension unit 70 converts the signal outputted
from the control circuit 58 to a power line communications
signal and transmits the power line communications signal
through the power lines (the terminals Tl and T3) by
overlapping same with the electric power.
In order to efficiently overlap the power line
communications signal with the electric power, it is
preferred as in the extension unit 68 of the power meter 29
that the impedance of the power lines, i.e., the impedance
between the terminals Tl and T3, in a communications
frequency band used for power line communications is kept
high.
Further, the power conditioner 50 is provided with a
power supply unit 71A for supplying the electric power
required to drive the control circuit 58 and so forth. The
power supply unit 71A is connected to the terminals Tl and
T3. The power supply unit 71A converts the electric power
inputted from the terminals Tl and T3 to the electric power
required to drive the control circuit 58 and so forth.
Similar to the power supply unit 91A of the power meter 29,
the power supply unit 71A serves to reduce the impedance of
the power lines connected to the input circuit thereof,
i.e., the impedance within a communications frequency band
used for power line communications. In the power supply
unit 71A, therefore, a matching circuit 71M, i.e., a so-
called impedance booster, for avoiding reduction of the
impedance of the power lines within a power line
communications frequency band is provided between the power
line and the input circuit of the power supply unit 71A so
that the power line communications can be efficiently
performed by the subordinate extension unit 70. As a
result, the power supply unit 71A can be connected to the
terminals Tl and T3 while restraining reduction of the
impedance between the terminals Tl and T3.
In the present embodiment, the extension unit 68 of
the power meter 29 and the subordinate extension unit 70 of
the power conditioner 50 make up a power line communications
unit, i.e., a first communications part, that enables the
power meter 29 and the power conditioner 50 to make power
line communications with each other.
The AC distribution board 11 is connected to the
display device 43 through the terminals Tl and T3. The
display device 43 performs visible display using the signal
acquired through .power line communications. The display
device 43 includes a terminal block 100 connected to the AC
distribution board 11 and the power conditioner 50 through
the power lines. The display device 43 includes a
communications unit 102 for making communications, through
power lines connected to the terminal block 100, with other
units connected to the power lines. The communications unit
102 is configured to make power line communications using
the power lines as a communications medium. The
configuration of the communications unit 102 is the same as
the configuration of the extension unit 68 of the power
meter 2 9 and the configuration of the subordinate extension
unit 7 0 of the pow.er conditioner 50.
In other words, the communications unit 102 includes:
a coupling circuit 103 that uses the power lines connected
to the terminals Tl and T3 as the communications medium, the
coupling circuit 103 connected to the communications medium;
a transceiver circuit 104 for transmitting and receiving a
modulated signal to and from the coupling circuit 103; and a
power line communications processing circuit 105 for
transmitting and receiving communications signal information
to and from the transceiver circuit 104. A control circuit
106 is connected to the power line communications processing
circuit 105, so that signals through power lines
communications are transmitted and received therebetween.
Accordingly, the communications unit 102 acquires a
power line communications signal, which is overlapped with
the electric power and received through the power lines (the
terminals Tl and T3) , and transfers the acquired signal to
the control circuit 106. Furthermore, the communications
unit 102 converts the signal outputted from the control
circuit 106 to a power line communications signal and
transmits the power line communications signal through the
power lines (the terminals Tl and T3) by overlapping same
with the electric power. In order to efficiently overlap
the power line communications signal with the electric
power, it is preferred as in the extension unit 68 of the
power meter 29 and the subordinate extension unit 70 of the
power conditioner 50 that the impedance of the power lines,
i.e., the impedance between the terminals Tl and T3, in a
communications frequency band used for power line
communications is kept high.
The display device 43 further includes a display unit
driving device 107 connected to the control circuit 106 and
a display unit 108 driven and controlled by the display unit
driving device 107. The control circuit 106 generates a
control signal to be visibly displayed on the display unit
108 by processing the signal transmitted from the
communications unit 102 and transfers the control signal to
the display unit driving device 107. Responsive to the
control signal transferred from the control circuit 106, the
display unit driving device 107 generates a drive signal for
driving the display unit 108 and transfers the drive signal
to the display unit 108. In response to the drive signal
transferred from the display unit driving device 107, the
display unit 108 displays the visible information such as a
numerical number and a graph on the display surface thereof.
The display device 43 is provided with a power supply
unit 101A for supplying the electric power required to drive
the control circuit 106 and so forth. The power supply unit
101A is connected to the terminals Tl and T3. The power
supply unit 101A converts the electric power inputted from
the terminals Tl and T3 to the electric power required to
drive the control circuit 106 and so forth. Similar to the
power supply unit 91A of the power meter 29 and the power
supply unit 71A of the power conditioner 50, the power
supply unit 101A serves to reduce the impedance of the power
lines connected to the input circuit thereof, i.e., the
impedance within a communications frequency band used for
power line communications.
In the power supply unit 101A, therefore, a matching
circuit 101M, i.e., a so-called impedance booster, for
avoiding reduction of the impedance of the power lines
within a power line communications frequency band is
provided between the power line and the input circuit of the
power supply unit 101A so that the power line communications
can be efficiently performed by the communications unit 102.
As a result, the power supply unit 101A can be connected to
the terminals Tl and T3 while restraining reduction of the
impedance between the terminals Tl and T3 within a power
line communications frequency band.
In the present embodiment, the subordinate extension
unit 7 0 of the power conditioner 50 and the communications
unit 102 of the display device 43 make up a power line
communications unit, i.e., a second communications part,
that enables the power conditioner 50 and the display device
4 3 to make power line communications with each other.
With such configuration, the extension unit 68 of the
power meter 2 9 and the subordinate extension unit 7 0 of the
power conditioner 50 are connected to each other through a
pair of power lines including the power line connected to
the terminals SI and Tl and the power line connected to the
terminals S3 and T3, so that they can make power line
communications with each other. The subordinate extension
unit 7 0 of the power conditioner 50 and the communications
unit 102 of the display device 43 are connected to each
other through a pair of power lines including the power line
connected to the terminal Tl and the power line connected to
the terminal T3, so that they can make power line
communications with each other.
Further, the subordinate extension unit 70 of the
power conditioner 50 has two communications targets, i.e.,
the extension unit 68 of the power meter 29 and the
communications unit 102 of the display device 43. By
allowing the communications targets to have different
communications frequencies or by allowing the communications
targets to have identification information that can identify
the communications targets, it is possible for the
subordinate extension unit 70 of the power conditioner 50 to
make independent communications with selected one of the
communications targets.
As a result, the power information of the power meter
29 is transferred to the power conditioner 50 through power
line communications and is collected in the memory device
50DB of the power conditioner 50 as power-related
information 50 J. The power conditioner 50 controls the
power consumption amounts of the respective DC appliances 5
based on the power management data of the power-related
information 50J stored in the memory device 50DB.
Consequently, the power conditioner 50 can control the
AC power supplied from the commercial power source and can
reversely supply the electric power generated by the solar
cell 3 to the commercial power source as much as possible.
In other words, the power conditioner 50 controls and
manages the power consumption amount of the entire power
supply system 1 based on the power-related information 50J.
At this time, the power conditioner 50 uses the power
information of the power meter 2 9 coinciding with the meter
reading data of the power company 60. It is therefore
possible for the power conditioner 50 to more properly
perform the electric power management of the entire power
supply system 1.
Further, the power-related information 50J, including
the power information of the power meter 29, collected in
the power conditioner 50 is transferred to the' display
device 43 and visually displayed to a user. At this time,
the power information of the power meter 29 is used to
thereby display to a user the billing information on the
electric power coinciding with the meter reading data of the
power company 60.
Further, the power meter 29 is able to make
communications with the system server 61 of the power
company 60. Therefore, if the power meter 29 acquires the
power-related information held by the system server 61, it
is possible for the power conditioner 50 to acquire the same
power-related information of the system server 61 as
acquired by the power meter 29. On the contrary, the system
server 61 may acquire the power-related information 50J of
the power conditioner 50 through the power meter 29. As a
result, the power conditioner 50 can perform the electric
power management based on the power-related information of
the system server 61. In addition, the power company 60 can
stabilize the electric power of the power system of the
commercial power source by referring to the power-related
information 50J of the power conditioner 50 acquired in the
system sever 61.
For example, upon acquiring the illuminance
information of the illuminometer 42 from a plurality of
power conditioners 50, the system server 61 can estimate the
illuminance change in the information-acquired region.
Moreover, the system server 61 can estimate the amount of
power to be outputted to the power system of the commercial
power source, based on the power generation information of
the solar cell 3 stored in the power conditioner 50. This
makes it possible to stabilize the power system of the
commercial power source. In addition, upon acquiring the
illuminance change estimation information from the system
server 61, the power conditioner 50 can estimate the power
generation amount of the solar cell 3. This makes it
possible to appropriately perform the electric power
management of the power supply system 1.
Further, for example, the system server 61 may provide
the information for stabilization of the system to the power
conditioner 50. In this case, the power conditioner 50
controls the input and output of the electric power between
the power systems of the commercial power source based on
the information for stabilization of the system thus
acquired. This control is performed by reducing the power
consumption of the DC appliances 5 through the cutoff of the
power supply or the change of the operation mode or by not
outputting the electric power generated by the solar cell 3.
This also makes it possible to stabilize the power system of
the commercial power source.
As described above, the electric power management
system in accordance with the present embodiment can provide
the following effects.
(1) In general, the power meter 29 is arranged outside
a house or a building and the power conditioner 50 is
arranged inside the house or the building. This makes it
difficult for the power conditioner 50 to acquire the power
information such as the amount of power measured by the
power meter 29.
In view of this, the first communications part is
provided to make communications between the power meter 29
and the power conditioner 50. As a result, the power
conditioner 50 can easily acquire from the power meter 29
the power information on the electric power inputted from or
outputted to the commercial power source, which is measured
by the power meter 29.
(2) The power information on the electric power
generated by the power generators such as the solar cell 3
and the battery 16, the power information on the electric
power consumed by the respective DC appliances 5 and the
power information on the electric power measured by the
power meter 29 are collected in the power conditioner 50.
It is therefore possible to appropriately carry out the
electric power management of the entire power supply system
1 based on the power information stated above. As a result,
it is possible for the power conditioner 50 to accurately
perform the centralized power management including the
management of the input and output of the electric power to
and from the power system. This assists in enhancing the
utility value of the electric power management system.
(3) The display device 43 can acquire the power
information collected in the power conditioner 50 through
the second communications part and can visibly display the
display information generated from the acquired power
information in the form of an image such as a numerical
number or a graph. This makes it easy to confirm the power
information collected in the power conditioner 50.
Accordingly, it is possible to enhance the utility value of
the electric power management system.
(4) By providing the subordinate extension unit 70 of
the power conditioner 50 and the communications unit 102 of
the display device 43 and enabling communications between
the subordinate extension unit 7 0 and the communications
unit 102, it is possible to easily transfer the power
information of the power conditioner 50 to the display
device 43.
(5) The communications between the power conditioner
50 and the display device 43 is performed by the power line
communications in which the power line is used as a
communications medium. This eliminates the need to install
communications wiring lines. It is therefore possible to
easily employ the electric power management system and to
increase the chance of employment of the electric power
management system.
(6) By providing the extension unit 68 (the first
extension unit) of the power meter 29 and the subordinate
extension unit 70 (the second extension unit) of the power
conditioner 50 and enabling communications between the
extension unit 68 and the subordinate extension unit 70, it
is possible for the extension unit 68 and the subordinate
extension unit 7 0 to exchange the power information of the
power meter 29 and the power information of the power
conditioner 50 with each other.
(7) The communications between the power meter 2 9 and
the power conditioner 50 is performed by the power line
communications in which the power line is used as a
communications medium. This eliminates the need to install
communications wiring lines. It is therefore possible to
easily employ the electric power management system and to
increase the chance of employment of the electric power
management system.
(8) The communications between the power meter 2 9 and
the power conditioner 50 and the communications between the
power conditioner 50 and the display device 43 are performed
through the power line communications in the same
communications method. In other words, the communications
methods of the first communications part and the second
communications part are unified into the power line
communications. .This makes it possible to simplify the
structure of the subordinate extension unit 70 of the power
conditioner 50, which is included in both of the first
communications part and the second communications part.
This also helps reduce the effort required in installing
communications equipment.
(9) The system server 61 managing the power system can
acquire the power information of the power conditioner 50 to
thereby estimate the power consumption trend and the like by
using the power management data based on the acquired power
information. For example, if the system server 61 performs
the management of the power system based on the power
consumption trend,- it is possible to further stabilize the
electric power of the power system and to increase the
utility value of the electric power management system.
(10) The power conditioner 50 acquires the power
information of the system server 61 from the power meter 29
and manages the power information together with the electric
power inputted from and outputted to the power system. As a
result, for example, if the power information of the system
server 61 contains the information for stabilization of the
system, the power conditioner 50 can adjust the electric
power inputted to and outputted from the commercial power
source, thereby stabilizing the power system. If the power
information of the system server 61 contains the billing
information, it is possible to perform the management of
electric power according to the charged fare.
(11) The power information on the power generation
amount of the solar cell 3 whose power generation pattern
varies largely depending on the daytime or nighttime and the
weather is managed by the power conditioner 50. It is
therefore possible to efficiently perform the management of
electric power by adjusting the power consumption pattern in
the house having the solar cell 3.
(Second Embodiment)
Next, an electric power management system in
accordance with a second embodiment of the present
invention will be described with respect to Figs. 4A and
4B. Figs. 4A and 4B are views schematically showing a
configuration in which the communications between the power
meter 2 9 and the power conditioner 50 and the
communications between the power conditioner 50 and the
display device 43 are performed through wireless
communications.
The second embodiment differs from the first
embodiment in that the communications between the power
meter 2 9 and the power conditioner 50 and the
communications between the power conditioner 50 and the
display device 43 are performed through wireless
communications. Other points remain the same as those of
the first embodiment. In the present embodiment,
description will be focused on the points differing from
the first embodiment. Like reference numerals will be
given to like parts, and redundant description thereof will
be omitted for the sake of convenience.
As shown in Figs. 4A and 4B, the power meter 29
includes current measuring units 82 and 83 for measuring
the currents flowing through the terminals SI and S3, a
voltage measuring unit 84 for measuring the voltage between
the terminals SI and S2 and a voltage measuring unit 85 for
measuring the voltage between the terminals S2 and S3. The
measured values are inputted to a control circuit 86. The
power amount calculated by the control circuit 8 6 is
displayed on a display circuit 87.
An extension unit 68A for performing wireless
communications is connected to the control circuit 86. The
extension unit 68A includes a wireless communications
circuit 95 and an antenna 96. The wireless communications
circuit 95 receives a signal from the control circuit 86
and transmits the received signal as a wireless signal.
Further, the wireless communications circuit 95 receives a
wireless signal and transfers the received wireless signal
to the control circuit 86.
The power meter 2 9 includes a power supply unit 91 for
supplying the electric power required to drive the control
circuit 86. The power supply unit 91 converts the electric
power inputted from the terminals SI and S3 to the electric
power required to drive the control circuit 86.
Further, the power meter 29 includes a terminal block
81 having terminals LI, L2 and L3. The terminals Ll and L3
of the terminal block 81 are connected to the terminals Tl
and T3 of an AC terminal block 51 of a power conditioner 50
through an AC distribution board 11.
The power conditioner 50 includes an inverter unit 53
arranged between the AC terminal block 51 and the DC
terminal block 52. The inverter unit 53 has an inverter
circuit 531 for performing AC-DC conversion/DC-AC
conversion of the electric power between the AC terminal
block 51 and the DC terminal block 52. The current and the
voltage of each of the power lines connected to the
terminals Tl and T3 of the AC terminal block 51 are
measured by an output current measuring unit 54 and an
output voltage measuring unit 55. The current and the
voltage of each of the power lines connected to the
terminals P and N of the DC terminal block 52 are measured
by an input current measuring unit 56 and an input voltage
measuring unit 57. The current and voltage values thus
measured are inputted to a control circuit 58. The control
circuit 58 drives and controls the inverter unit 53 based
on the current and voltage values thus measured.
A subordinate extension unit 70A for performing
wireless communications is connected to the control circuit
58. The subordinate extension unit 70A includes a wireless
communications circuit 76 and an antenna 77. The wireless
communications circuit 7 6 receives a signal from the
control circuit 58 and transmits the received signal as a
wireless signal. The wireless communications circuit 76
receives a wireless signal and transfers the received
wireless signal to the control circuit 58.
Further, the power conditioner 50 includes a power
supply unit 71 for supplying the electric power required to
drive the control circuit 58. The power supply unit 71
converts the electric power inputted from the terminals Tl
and T3 to the electric power required to drive the control
circuit 58.
In the present embodiment, the extension unit 68A of
the power meter 29 and the subordinate extension unit 70A
of the power conditioner 50 make up a wireless
communications unit as a first communications part that
enables wireless communications between the power meter 29
and the power conditioner 50.
In the power conditioner 50, the terminals P and N of
the DC terminal block 52 are connected to a terminal block
100 of the display device 43. The display device 43
includes a displaying unit 108 driven and controlled by a
display unit driving device 107 under the control of a
control circuit 106. The display device 43 further
includes a communications unit 102A for performing wireless
communications. The communications unit 102A includes a
wireless communications circuit 109 and an antenna 110.
The wireless communications circuit 109 receives a signal
from the control circuit 106 and transmits the received
signal as a wireless signal. The wireless communications
circuit 109 receives a wireless signal and transfers the
received wireless signal to the control circuit 106.
Further, the display device 43 includes a power supply
unit 101 for supplying the electric power required to drive
the control circuit 106. The power supply unit 101
converts the electric power inputted from the terminals P
and N to the electric power required to drive the control
circuit 106.
In the present embodiment, the subordinate extension
unit 7 0A of the power conditioner 50 and the communications
unit 102A of the display device 43 make up a wireless
communications unit as a second communications part that
enables wireless communications between the power
conditioner 50 and the display device 43.
With such configuration, the extension unit 68A of the
power meter 29 and the subordinate extension unit 70A of the
power conditioner 50 are connected to each other such that
they can make wireless communications with each other. The
subordinate extension unit 70A of the power conditioner 50
and the communications unit 102A of the display device 43
are connected to each other such that they can make wireless
communications with each other. The subordinate extension
unit 7 0A of the power conditioner 50 has two communications
targets, i.e., the extension unit 68A of the power meter 29
and the communications unit 102A of the display device 43.
By allowing the communications targets to have different
communications frequencies or by allowing the communications
targets to have identification information that can identify
the communications targets, it is possible for the
subordinate extension unit 70A of the power conditioner 50
to make independent communications with the selected one of
the communications targets.
As a result, the power information of the power meter
29 is transferred to the power conditioner 50 and is
collected in the memory device 50DB of the power conditioner
50 as power-related information 50J. The power conditioner
50 controls and manages the power consumption amount of the
entire power supply system 1 based on the power management
data of the power-related information 50J stored in the
memory device 5 0DB. At this time, the power conditioner 50
uses the power information of the power meter 29 coinciding
with the meter reading data of the power company 60. It is
therefore possible for the power conditioner 50 to more
properly perform the electric power management of the entire
power supply system 1.
Further, the power-related information 50J, including
the power information of the power meter 29, collected in
the power conditioner 50 is transferred to the display
device 43 and visually displayed to a user. At this time,
the power information of the power meter 29 is used to
thereby display to a user the billing information on the
electric power coinciding with the meter reading data of the
power company 60.
As described above, the present embodiment can provide
effects identical with or similar to effects (1) to (6) and
(9) to (11) provided by the first embodiment that performs
power line communications. In addition, the present
embodiment can provide the following effects.
(12) Since the communications between the power
conditioner 50 and the display device 43 is performed by
wireless communications, it becomes unnecessary to install
wiring lines for communications purposes. This makes it
possible to increase the degree of freedom in arranging the
electric power management system.
(13) Since the communications between the power meter
2 9 and the power conditioner 50 is performed by wireless
communications, it becomes unnecessary to install wiring
lines for communications purposes. This makes it possible
to increase the degree of freedom in arranging the electric
power management system and to facilitate use of the
electric power management system.
The respective embodiments described above may be
modified as follows.
In the respective embodiments described above, there
is illustrated a case in which the control unit 7 and the DC
distribution board 8 are included in the power conditioner
50. However, the present invention is not limited thereto.
Various devices, e.g., an AC distribution board, a control
box and a home server, may be included in the power
conditioner 50 as long as they enables the power supply
system to properly perform the management of electric power.
On the contrary, the DC distribution board 8 may be excluded
from the power conditioner 50. This makes it possible to
increase the degree of freedom in configuring the power
conditioner and to increase the chance of use of the
electric power management system.
In the respective embodiments described above, there
is illustrated a case in which the power conditioner 50 is
provided with the memory device 50DB. However, the present
invention is not limited thereto. The memory device may not
be provided in the power conditioner as long as the power
conditioner can manage the power information. In this case,
the power information may be stored in the home server or
the like so that the power conditioner can gain access
thereto. This makes it possible to increase the degree of
freedom in configuring the power conditioner and to increase
the chance of use of the electric power management system.
In the first embodiment described above, there is
illustrated a case in which the display device 43 is
connected to the AC terminal block 51 of the power
conditioner 50 so as to make power line communications with
the power conditioner 50.
However, the present invention is not limited thereto.
The display device may be connected to the DC terminal block
of the power conditioner so as to make power line
communications with the power conditioner 50. For example,
as shown in Fig. 5, a matching circuit 53N for restraining
reduction of the impedance of the power line is further
provided at the DC side of the inverter circuit 531 of the
inverter unit 53B of the power conditioner 50 so as to avoid
reduction of the impedance between the terminals P and N of
the DC terminal block 52. There are provided a transceiver
circuit 78 and a coupling circuit 79 for overlapping a power
line communications signal with the terminals P and N of the
DC terminal block 52. The transceiver circuit 78 is
connected to the power line communications processing
circuit 75 for transmitting and receiving communications
signals. The display device 43 is provided with a power
supply unit coping with the input of DC power and having a
matching circuit.
Accordingly, as shown in Fig. 6, the communications
between the power meter 2 9 and the power conditioner 50 can
be performed through the power line communications (PLC) in
which a signal is conveyed by the AC power. The
communications between the power conditioner 50 and the
display device 43 can be performed through the power line
communications (PLC) in which a signal is conveyed by the DC
power.
In the second embodiment, there is illustrated a case
in which the DC power applied to the DC terminal block 52 of
the power conditioner 50 is used as the source power of the
display device 43. However, the present invention is not
limited thereto. The source power of the display device 43
may be AC power and the power conditioner 50 may make
wireless communications. As shown in, e.g., Fig. 7, it is
therefore possible to provide a combination in which the
communications between the power meter 2 9 and the power
conditioner 50 and the communications between the power
conditioner 50 and the display device 43 are performed by
wireless communications and in which AC power is used as the
source power of the power meter 29, the power conditioner 50
and the display device 43.
In the respective embodiments described above, there
is illustrated a case in which the power-related information
50J of the power conditioner 50 is displayed by the display
device 43. However, the present invention is not limited
thereto. If recognizable by a user, the power-related
information of the power conditioner may be provided in the
form of an image or a voice through a device having a user
interface, such as an operation panel 40, a door phone
extension unit or a television set, each of which is
communicatively connected to the power conditioner 50. This
makes it possible to increase the degree of freedom in
configuring the electric power management system.
In the respective embodiments described above, there
is illustrated a case in which the power meter 29 makes
communications with the system server 61. However, the
present invention is not limited thereto. The power meter
may be allowed to make communications with a different base
unit through the base unit installed in the electric pole.
That is, the power meter makes communications with a
different power meter through the base unit, which makes it
possible for the power conditioner of the power meter to
acquire the information of a power conditioner of the
different power meter.
For example, seven to ten houses are connected to
step-down transformers. Base units are provided in a
corresponding relationship with every step-down transformer
or some of the step-down transformers. In this case, the
power meter can make communications through the base unit
with another power meter connected to the step-down
transformer corresponding to the base unit. This makes it
possible to make interactive communications through the
power meter in a limited area. For example, the information
on the availability of electric power can be exchanged
between the adjoining power conditioners. This
configuration can also be used in transferring various kinds
of information, which is not directly related to the
electric power, such as the notice information and the crime
prevention information.
In the respective embodiments described above, there
is illustrated a case in which the subordinate extension
unit 70 of the power conditioner 50 is used as both the
second extension unit of the first communications part and
the subordinate extension unit of the second communications
part. However, the present invention is not limited
thereto. The second extension unit for the first
communications part and the subordinate extension unit for
the second communications part may be independently provided
in the power conditioner. This makes it possible to
increase the degree of freedom in performing communications
between the power conditioners.
In the respective embodiments described above, there
is illustrated a case in which the solar cell 3 is used as a
power generating device. However, the present invention is
not limited thereto. The power generating device may be
other devices having a power generating function, such as a
battery, a fuel cell and a wind power generation device.
While the invention has been shown and described with
respect to the embodiments, it will be understood by those
skilled in the art that various changes and modification may
be made without departing from the scope of the invention as
defined in the following claims.
WE CLAIM:
1 . An electric power management system, comprising:
a power meter connected to a power system of a
commercial power source; and
a power conditioner connected to the power meter, a
power generating device and an electric appliance,
wherein the power meter and the power conditioner
exchange power information through a communications part at
a side of the power meter.
2. The electric power management system of claim 1,
wherein the power meter is connected to the power system of
the commercial power source to acquire power information
from an electric power inputted from the power system and an
electric power outputted to the power system,
wherein the power conditioner is configured to collect
power information of the power generating device; power
information of the electric appliance; and the power
information on the electric power inputted from the power
system and the power information on the electric power
outputted to the power system, which are acquired from the
power meter through the communications part at the side of
the power meter, and to manage the electric power inputted
from the power system and the electric power outputted to
the power system, based on the collected power information.
3. The electric power management system of claim 2,
further comprising:
a display device for acquiring the power information
collected in the power conditioner from the power
conditioner through a communications part at a side of the
display device and visually displaying the acquired power
information on a display unit.
4. The electric power management system of claim 3,
wherein the communications part at the side of the display
device includes a subordinate extension unit provided in the
power conditioner to transmit the power information
collected in the power conditioner and a communications unit
provided in the display device to receive the power
information transmitted from the subordinate extension unit.
5. The electric power management system of claim 4,
wherein the communications part at the side of the power
meter includes a first extension unit provided in the power
meter to transmit the power information acquired from the
power meter and a second extension unit provided in the
power conditioner to receive the power information
transmitted from the first extension unit.
6. The electric power management system of claim 5,
wherein the second extension unit of the power conditioner
serves as the subordinate extension unit of the
corresponding power conditioner.
7. The electric power management system of any one of
claims 2 to 6, wherein the power meter further includes a
device communicatively connected to a system server for
managing the power system of the commercial power source and
configured to acquire the power information collected in the
power conditioner through the communications part at the
side of the power meter and transfer the acquired power
information to the system server.
8. The electric power management system of claim 7,
wherein the power conditioner is configured to acquire power
information held by the system server through the power
meter and to manage the acquired power information.

ABSTRACT

An electric power management system includes a power meter connected to a power system of a commercial power source and a power conditioner connected to the power meter, a power generating device and an electric appliance. The power meter and the power conditioner are configured to
exchange power information through a communications part at
the side of the power meter.