JP2016007133A - Power control system and server - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power control system capable of providing equal opportunity to sell surplus power to plural users sharing a single transformer.SOLUTION: A power control system 10 includes: a control section 27 that controls the output voltage from a power conditioner 22 to thereby allow each of plural users 1 as a same bank to sell the power for power selling period of a predetermined length; and a transmission and reception circuit 28. The control section 27 communicates with different users 1 in the same bank to sequentially provide equal opportunity of power selling period to the plural users 1 in the same bank.

Description

  The present invention relates to a power control system and a server used for a plurality of consumers who share a single transformer.

  2. Description of the Related Art Conventionally, distributed power sources such as solar cells and fuel cells are installed in consumers, and a part of power required by consumers is covered by the distributed power sources. In particular, in the case of solar cells, when surplus power is generated (when the output of the solar cell is greater than the power consumed by the consumer's load), the surplus power of the solar cell generally flows backward to the commercial power system. And sold to a power company.

  A distributed power supply that acquires power generation amount information of one or more distributed power sources connected to a communication network as a system used for power sale and supplies the power generation amount of each distributed power source to the transmission and distribution system based on the acquired information A system having a control system has been proposed (see, for example, Patent Document 1).

JP 2006-280154 A

  However, as distributed power sources such as solar cells become more widespread in the future, distributed power sources will be installed in multiple customers who share one transformer (so-called “same bank”). The following problems can occur. In other words, when multiple customers in the same bank try to sell surplus power all at once, there may be a customer who cannot sell (reverse power flow) depending on the positional relationship with the transformer. There may be variations in power sales opportunities.

  The present invention has been made in view of the above-described reasons, and provides a power control system and a server that can evenly give an opportunity for selling surplus power to a plurality of consumers who share one transformer. The purpose is to provide.

  The power control system according to the present invention includes a plurality of consumers that draw a commercial power system from a common transformer, and is capable of supplying a distributed power source that generates power and the power generated by the distributed power source to a load circuit. A power conditioner that converts power into electric power and sells power by flowing the surplus power back to the commercial power system when there is surplus power in the electric power generated by the distributed power supply Each of the plurality of consumers includes a control unit that controls the power conditioner and sells power for a predetermined length of power selling period. And a server configured to be able to communicate with each of the plurality of control units, and the server sells the control unit with each of the plurality of control units according to a voltage level of the commercial power system. And allocating a time.

  In this power control system, it is more desirable that the server increase the number of the control units that issue the power sale permission at the same time as the voltage of the commercial power system becomes lower than the upper limit value.

  The server according to the present invention is used in the power control system described above.

  According to the present invention, since a power selling period is allocated to each consumer by communication, it is possible to evenly give a chance to sell surplus power to a plurality of consumers who share one transformer. There are advantages.

1 is a system configuration diagram illustrating a power control system according to a first embodiment. It is explanatory drawing of operation | movement of the electric power control system which concerns on Embodiment 1. FIG. It is explanatory drawing of operation | movement of the electric power control system which concerns on Embodiment 1. FIG. It is a block diagram of the principal part which shows the other example of the electric power control system which concerns on Embodiment 1. FIG. FIG. 3 is a system configuration diagram illustrating a power control system according to a second embodiment. FIG. 10 is an explanatory diagram of an operation of the power control system according to the second embodiment. FIG. 10 is an explanatory diagram of an operation of the power control system according to the second embodiment.

(Embodiment 1)
As shown in FIG. 1, the power control system 10 of the present embodiment includes a plurality of consumers 11, 12,... Each having a solar battery 20 as a distributed power source (hereinafter referred to as “customer 1” when not particularly distinguished from each other). "). In this power control system 10, in each customer 1, grid connection is performed between the solar battery 20 and a commercial power system supplied from an electric power company, and power is supplied to a load circuit 21 including a plurality of electric devices. Here, a general detached house will be described as an example of the consumer 1, but the present invention is not limited thereto, and each dwelling unit, facility, factory, etc. of the apartment house may be the consumer 1.

  The solar cell 20 is connected to a power conditioner 22 having an inverter circuit (not shown). The power conditioner 22 converts the DC power generated by the solar cell 20 into AC power using an inverter circuit and outputs the AC power. A storage battery 23 as a power storage unit is also connected to the power conditioner 22, and the power conditioner 22 charges and discharges the storage battery 23. That is, the power conditioner 22 charges the storage battery 23 by the output of the solar cell 20 in the daytime, for example, and converts the power stored in the storage battery 23 into AC power by the inverter circuit and outputs it at night.

  Each consumer 1 is provided with a distribution board 24 to which the load circuit 21 is connected, and the power conditioner 22 is connected to the distribution board 24. Outputs of the solar battery 20 and the storage battery 23 are converted into an AC voltage having substantially the same voltage and frequency as those of the commercial power system by the power conditioner 22 and supplied to the load circuit 21 via the distribution board 24.

  The distribution board 24 is also connected to the lead-in line 30 of the commercial power system via the power meter 25, and when the power consumed by the load circuit 21 cannot be covered only by the outputs of the solar battery 20 and the storage battery 23. The power supply from the commercial power system to the load circuit 21 is enabled. In addition, in the consumer 1 which performs grid connection in this way, it is necessary to prevent the single operation of the solar cell 20 at the time of a power failure of a commercial power system. Accordingly, a protection device that stops the operation of the inverter circuit of the power conditioner 22 when a power failure is detected in the commercial power system and disconnects (opens) the disconnect relay 26 inserted between the lead-in wire 30 and the power conditioner 22. (Not shown) is provided for each customer 1. The protective device is provided in the power conditioner 22.

  The lead-in wire 30 of the commercial power system is connected to the consumer 1 side (hereinafter referred to as “secondary side”) of the transformer 31. The transformer 31 has a primary side connected to a distribution line 32 that distributes power from an electric power company, and a high voltage (for example, 6.6 to 3.3 kV) applied from the distribution line 32 to a low voltage (for example, 200 to 100 V). The product is converted and supplied to the customer 1 from the secondary side via the service line 30. Although the transformer 31 consists of a pole transformer here, the form of the transformer 31 is not restricted to a pole transformer. In a densely populated area or the like, a plurality of neighboring customers 1 share one transformer 31, and the plurality of consumers 1, which are so-called “same bank”, are transformed by the same transformer 31. Electric power is drawn through the lead-in line 30. A plurality of customers 1 in the same bank constitute a customer group.

  In the above configuration, when the generated power of the solar cell 20 exceeds the power consumption of the load circuit 21 during the daytime when the power is sufficiently generated by the solar cell 20, a surplus (hereinafter referred to as the power generated by the solar cell 20). , “Surplus power”). The surplus power can be stored in the storage battery 23, but can also be sold to an electric power company by flowing backward from the service line 30 to the commercial power system. Therefore, between the service line 30 and the distribution board 24, as a power meter 25, in addition to a power purchase meter that measures the amount of power supplied from the commercial power system to the consumer 1, the consumer 1 to the commercial power system. There is a power sale meter that measures the amount of power that flows backward.

  The surplus power is sold by the power conditioner 22 adjusting the voltage and frequency of the surplus power. That is, the power conditioner 22 converts surplus power into AC power having a voltage (effective value) higher than that of the commercial power system drawn from the lead-in line 30 and having the same frequency as that of the commercial power system. Reverse power flow of surplus power. For example, if the voltage of the commercial power system (hereinafter referred to as “system voltage”) is 100 V (effective value), the power conditioner 22 converts the surplus power into AC power exceeding 100 V to reverse the power to the commercial power system. Tidal current.

  By the way, when the solar cell 20 is installed in each of a plurality of customers (customers common to the transformer 31) 1 in the same bank, the following problems may occur.

  In general, when a large number of consumers 1 use electricity all at once, the grid voltage transmitted through the distribution line 32 may decrease and affect the electrical equipment. The band supply voltage (system voltage) is slightly higher than other normal time zones. Therefore, when selling surplus power generated by the customer 1 in a time zone when the power demand is high, the power conditioner 22 needs to convert the surplus power to a voltage higher than that in the normal time zone. However, the output voltage of the power conditioner 22 is limited to a predetermined range (for example, a range of 101 ± 6 V) in consideration of the influence on other consumers 1. Therefore, when the supply voltage (system voltage) from the electric power company becomes high, the output voltage of the power conditioner 22 may not exceed the system voltage in the consumer 1 and may not be able to sell power (so-called voltage rise suppression problem). ).

  Here, when the solar cell 20 is installed in each of the plurality of consumers 1 in the same bank, the power conditioner 22 needs to output a higher voltage to the consumer 1 farther from the transformer 31 when selling power. . That is, in order for a plurality of consumers 1 in the same bank to sell power all at once, it is necessary to apply a voltage higher than the system voltage to the secondary side of the transformer 31. It is necessary to output a higher voltage for the consumer 1 far away from the vehicle. For example, if the system voltage on the secondary side of the transformer 31 is 106 V, the consumer 1 closest to the transformer 31 can sell power at an output of 107 V, whereas the consumer far from the transformer 31 1 requires an output of 108V to sell power.

  Therefore, when the solar cell 20 is installed in each of the plurality of consumers 1, the consumer 1 far from the transformer 31 sells due to the above-described voltage rise suppression problem in a time period when the power demand is high and the system voltage is high. There is a high possibility that power will be lost. In other words, when a plurality of customers 1 in the same bank try to sell surplus power all at once, depending on the positional relationship with the transformer 31, there may be a customer 1 who cannot sell (reverse power flow). There is a possibility that there will be variations in the opportunities for selling power among consumers 1.

  Therefore, the power control system 10 according to the present embodiment employs the configuration described below so that a plurality of consumers 1 in the same bank are equally given the opportunity to sell power.

  In other words, the power control system 10 sells power to a plurality of consumers 1 in the same bank by controlling the output voltage of the power conditioner 22 over a predetermined length (for example, 10 minutes) of power selling period. A control unit 27 is provided. In the present embodiment, the control unit 27 is provided in the power meter 25 of each consumer 1.

  In the power control system 10, the control unit 27 communicates between different customers 1 in the same bank, so that a plurality of consumers 1 in the same bank are equally given the opportunity to sell power. As described above, a power sale period for selling surplus power is allocated to each consumer 1. In the present embodiment, a transmission / reception circuit unit 28 for PLC (Power Line Communication) is attached to the control unit 27 in the power meter 25, and is connected between the control units 27 of a plurality of consumers 1 connected to the same transformer 31. A communication network using PLC has been established. The control unit 27 is configured to be able to communicate with each other between the consumers 1 in the same bank. The control part 27 of each consumer 1 has memorize | stored the address of the other consumer 1 in the same bank, respectively, and communicates bidirectionally using this address. That is, each control unit 27 constitutes a communication node.

  Specifically, when surplus power is generated, the control unit 27 transmits an RTS (Request to Send) as a power reception request to the control unit 27 of another customer 1 in the same bank by communication. The control unit 27 that has transmitted the RTS is assigned a power sale period by receiving a CTS (Clear to Send) as a response to the RTS, and outputs the output voltage of the power conditioner 22 over the assigned power sale period. Selling surplus power. That is, the power selling period is a period of a predetermined length from the time when the CTS is returned. Here, the length of the power selling period may be determined uniformly, or may be different depending on the time zone, day of the week, season, or the like. When the length of the power sale period is not uniform, the control unit 27 is notified of the length of the power sale period together with the CTS.

  On the other hand, if the control unit 27 cannot receive the CTS as a response to the RTS, the control unit 27 retransmits the RTS after a waiting time described later. The RTS is multicast-transmitted to the control unit 27 of the customer 1 in the same bank, and the node that can receive power among the nodes (control unit 27) that has received the RTS returns the CTS to the node that transmitted the RTS.

  Moreover, in this embodiment, the control part 27 detects the end time of communication of the other customer 1 in the same bank, and passes through the random waiting time from which the length differs for every customer 1 from the said end time, Communication for assigning a power sale period as described above is performed. In other words, the plurality of control units 27 in the same bank use CSMA / CA (Carrier Sense Multiple Access with Collision Avoidance) as an access control method, thereby sharing one communication path (communication network). Can communicate with each other.

  More specifically, in this embodiment, the control unit 27 performs reception once before transmitting RTS (or CTS), and checks whether there is another control unit 27 in communication in the same bank ( Career sense). At this time, if there is no other communicating control unit 27, the control unit 27 immediately transmits an RTS (or CTS), and if there is another communicating control unit 27, the other control unit 27 After waiting for a random length after detecting the end of communication, RTS (or CTS) is transmitted. In addition, in order to avoid the situation where the specific control part 27 cannot transmit forever, the length of waiting time is gradually shortened.

  Hereinafter, an operation example of the power control system 10 having the above configuration will be described with reference to FIG. Here, a case will be described as an example where surplus power is generated in the customer 12 and the customer 13 among the consumers 11 to 14 in the same bank, and this surplus power is supplied to the customer 11.

  When surplus power is generated in the customer 12, the control unit 27 of the customer 12 immediately transmits an RTS because there is no other control unit 27 in communication in the same bank at that time in the example of FIG. To do. At this time, since the consumer 11 is in a power receivable state, the control unit 27 of the consumer 11 returns a CTS as a response to the RTS to the control unit 27 of the consumer 12. Thereby, the control part 27 of the consumer 12 raises the output voltage of the power conditioner 22 over the power sale period immediately after receiving CTS, and sells surplus power (power transmission to the consumer 11).

  On the other hand, when surplus power is generated in the consumer 13, the control unit 27 of the consumer 13 transmits the RTS in the example of FIG. 2 because the control unit 27 of the consumer 12 is communicating at that time. Instead, the counting of the waiting time (back-off time) is started from the end of the communication. When the waiting time elapses, the control unit 27 of the consumer 13 transmits an RTS. At this time, when the consumer 12 sells power, the consumer 11 is not in a state capable of receiving power, and no CTS is returned to the control unit 27 of the consumer 13. Therefore, the control unit 27 of the consumer 13 counts a waiting time shorter than the previous waiting time, and retransmits the RTS after the waiting time has elapsed. At this time, since the consumer 11 is in a power receivable state, the control unit 27 of the consumer 11 returns a CTS as a response to the RTS to the control unit 27 of the consumer 13. Thereby, the control part 27 of the consumer 13 raises the output voltage of the power conditioner 22 over the power sale period immediately after receiving CTS, and sells surplus power (power transmission to the consumer 11).

  In addition, the power control system 10 of the present embodiment is not limited to the operation as shown in FIG. 2 described above, and power is sold by another consumer 1 when the control unit 27 of a certain consumer 1 communicates. In such a case, the power sale for the power sale period may be started after waiting for the power sale of the other consumer 1 to end. With reference to FIG. 3, the operation in the case where power selling is started after waiting for the end of the power selling of other consumers 1 will be described below. Here, a case will be described as an example where surplus power is generated in the customer 12 and the customer 13 among the consumers 11 to 14 in the same bank, and this surplus power is supplied to the customer 11.

  When surplus power is generated in the customer 12, the control unit 27 of the customer 12 immediately transmits an RTS because there is no other control unit 27 in communication in the same bank at that time in the example of FIG. To do. At this time, since the consumer 11 is in a power receivable state, the control unit 27 of the consumer 11 returns a CTS as a response to the RTS to the control unit 27 of the consumer 12. Thereby, the control part 27 of the consumer 12 raises the output voltage of the power conditioner 22 over the electric power selling period from the time of receiving CTS, and sells surplus electric power (power transmission to the consumer 11).

  On the other hand, when the surplus power is generated in the consumer 13, the control unit 27 of the consumer 13 transmits the RTS in the example of FIG. 3 because the control unit 27 of the consumer 12 is communicating at that time. Instead, the counting of the waiting time (back-off time) is started from the end of the communication. When the waiting time elapses, the control unit 27 of the consumer 13 transmits an RTS. At this time, since the consumer 11 is not in a state capable of receiving power by the consumer 12 selling power, the control unit 27 of the consumer 11 indicates that power can be received after the end of the power selling period of the consumer 12. The CTS is returned as a response to the RTS to the control unit 27 of the consumer 13. In short, since communication signals (RTS, CTS) use high frequencies, the control unit 27 can transmit and receive communication signals even during power sale or power reception. Therefore, the control unit 27 of the consumer 11 notifies the control unit 27 of the consumer 13 of the remaining time (or end time) of the power sale period of the consumer 12 using the communication signal (CTS). In other words, the control unit 27 of the consumer 13 makes a reservation for the power sale period after the end of the power sale of the consumer 12 through communication with the control unit 27 of the consumer 11.

  The control unit 27 of the consumer 13 counts the remaining time notified from the control unit 27 of the customer 11 and immediately increases the output voltage of the power conditioner 22 over the power sale period after the remaining time has elapsed. Selling surplus power (power transmission to the customer 11). Thereby, after the end of the power selling period of the consumer 12, the reserved consumer 13 can immediately sell the power.

  According to the configuration described above, the control unit 27 communicates between different customers 1 in the same bank, so that a plurality of customers 1 in the same bank can sell surplus power to the power sale period. Are sequentially allocated by being separated by a predetermined length. In short, the control unit 27 detects the end point of communication of another customer 1 in the same bank, and allocates a power selling period through a random waiting time having a different length for each customer 1 from the end point. CSMA / CA that performs the above communication is adopted as an access control method. Thereby, the plurality of consumers 1 in the same bank is given an opportunity to sell surplus power regardless of the positional relationship with the transformer 31. Therefore, even when the solar cells 20 are installed in the plurality of consumers 1 in the same bank, the plurality of consumers 1 can be distributed to the plurality of consumers 1 without any variation in the opportunities for selling power. This will give equal opportunities to sell electricity.

  Further, in the power control system 10, the opportunity for selling power is sequentially given to the plurality of consumers 1 in the same bank one by one, so that the plurality of consumers 1 in the same bank do not sell power simultaneously. Therefore, according to the power control system 10, it is possible to suppress the increase in the voltage on the secondary side of the transformer 31 associated with power sale, as compared to the case where a plurality of consumers 1 sell power simultaneously. The influence on other customers 1 who are not selling power can be suppressed.

  In addition, in the present embodiment, each consumer 1 is provided with a storage battery 23. Therefore, in the consumer 1 where surplus power is generated in a state where no opportunity for power sale is given, this surplus power is stored in the storage battery 23. It can be used effectively by accumulating in.

  Further, since the control unit 27 is provided in the power meter 25 of each consumer 1, the addition of the control unit 27 does not increase the number of devices constituting the power control system 10 and is the same as the conventional one. The power control system 10 can be constructed with the number of devices.

  Note that the control unit 27 adopts CSMA / CD (Carrier Sense Multiple Access with Collision Detection) as an access control method, in which communication is stopped when a plurality of nodes simultaneously perform communication, and communication is resumed after a random waiting time. May be. Even in this case, the plurality of consumers 1 in the same bank are given an opportunity to sell surplus power regardless of the positional relationship with the transformer 31. However, as compared with the case where CSMA / CD is adopted, the control unit 27 can avoid communication collision and can efficiently sell power when the CSMA / CD is adopted.

  Moreover, in this embodiment, although the control part 27 is each provided in the electric power meter 25 of each consumer 1, not only this structure but the control part 27 is each in the power conditioner 22 of each consumer 1. It may be provided. In this case, a wiring for the control unit 27 to control the output voltage of the power conditioner 22 can be provided in the power conditioner 22.

  In addition, in the said embodiment, although all the consumers 1 in the same bank showed the example provided with the solar cell 20, not only this example but multiple customers 1 provided with the solar cell 20 in the same bank are included. It only has to be.

  By the way, the power control system 10 includes a power distribution control unit that supplies surplus power reversely flowed to the commercial power system by the power conditioner 22 to another customer 1 in the same bank or to a customer 1 in another bank. It may be. In this case, for example, as shown in FIG. 4, the control unit 27 and the transmission / reception circuit unit 28 are provided in the power conditioner 22 of each consumer 1, and the control unit 27 and the transmission / reception circuit unit 28 constitute a power distribution control unit.

  The power distribution control unit identifies a supply destination of surplus power generated in a certain consumer 1 from other consumers 1 in the same bank or the consumer 1 in another bank, and surplus power for the identified supply destination Power distribution. Specifically, the power distribution control unit grades the output voltage of the power conditioner 22 through communication between the plurality of consumers 1 so that surplus power is supplied to the specific consumers 1. .

  Here, the consumer 1 as a supply destination of surplus power may be a facility shared in an area including the consumer 1 that has generated surplus power, such as a community facility, or a general door. It may be a built house. In addition, when power storage facilities are provided in each region, the power distribution control unit may set the surplus power supply destination as the power storage facility, and accumulate the surplus power generated in the region in the power storage facility. Good. In this case, the storage battery 23 of each consumer 1 may be omitted.

  In addition, the power distribution control unit stabilizes power by supplying surplus power generated in a certain consumer 1 to a consumer 1 in a remote area based on local weather information that can be acquired from a weather server or the like. Can be planned. That is, since the generated power of the solar cell 20 varies greatly due to the influence of the weather, even if the solar cell 20 having the same specification is used, the generated power is smaller in a rainy region than in a clear region. Therefore, the power distribution control unit can stabilize the power among a plurality of regions by supplying surplus power generated by the customers 1 in a sunny area to the consumers 1 in a rainy region.

  As described above, according to the power control system 10 including the power distribution control unit, in addition to selling surplus power generated in the customer 1 to the power company, it is possible to buy and sell power between the customers 1 or between regions. become.

(Embodiment 2)
In the power control system 10 of the present embodiment, as shown in FIG. 5, one server 4 that allocates a power sale period to the control unit 27 of each consumer 1 is provided for each bank including a plurality of consumers 1. This is different from the power control system 10 of the first embodiment.

  The server 4 allocates a power sale period to the control unit 27 of each consumer 1 so that the power sale opportunities are equally given to the plurality of consumers 1 in the same bank. The server 4 is configured to be capable of bidirectional communication with the control unit 27 of each customer 1 via the transmission / reception circuit unit 28. That is, in this embodiment, each control unit 27 and the server 4 constitute a communication node.

  Specifically, the modem 5 is connected to the secondary side of the transformer 31, and the server 4 is connected to the modem 5 via a cable (for example, an optical cable) 51. The modem 5 demodulates the PLC signal transmitted from the transmission / reception circuit unit 28 into a communication signal and transmits it to the server 4, or modulates the communication signal transmitted from the server 4 into a PLC signal and transmits it to the transmission / reception circuit unit 28. Or The server 4 and the control unit 27 each store a mutual address, and perform bidirectional communication using the address.

  In the present embodiment, the control units 27 of the plurality of consumers 1 within the same bank determine the timing for selling power (that is, the start timing of the power selling period) in accordance with an instruction from the server 4. The server 4 sequentially assigns a power sale period to each consumer 1 by sequentially transmitting a power sale permission to the control unit 27 of each consumer 1 by communication. The order in which the server 4 transmits the power sale permission is predetermined and stored in the server 4 so that a plurality of consumers 1 in the same bank are equally given the opportunity to sell power.

  The control unit 27 that has received the power sale permission determines whether or not power sale is possible at that time, that is, whether or not surplus power is generated. If the power sale is possible (with surplus power), A signal of permission acceptance is returned to the server 4 by communication as a response to the power sale permission. On the other hand, if the power sale permission is received, the control unit 27 returns a permission decline signal to the server 4 by communication as a response to the power sale permission if the power sale is not possible (no surplus power). When there is a reply of permission refusal from the control unit 27 that has issued the power sale permission, the server 4 transmits a power sale permission to the control unit 27 of the next consumer 1 until there is a reply of permission acceptance. The power sale permission is sequentially transmitted to the control unit 27 of each consumer 1.

  When there is a reply of permission acceptance from any of the consumers 1, the server 4 sets a power sale period for selling surplus power to the consumer 1 that has returned permission acceptance. That is, the power sale period is a predetermined length from the time when the permission acceptance is returned. Here, the length of the power selling period may be determined uniformly, or may be different depending on the time zone, day of the week, season, or the like. If the length of the power sale period is not uniform, the server 4 notifies the control unit 27 of the length of the power sale period together with the power sale permission.

  When the control unit 27 returns a permission acceptance, the surplus power is sold by increasing the output voltage of the power conditioner 22 from that time point over the power sale period. However, when the power cannot be sold because the surplus power runs out, the control unit 27 stops the power sale by reducing the output voltage of the power conditioner 22 even during the power sale period. On the other hand, when a reply of permission decline is made, the control unit 27 does not sell surplus power.

  The server 4 is connected to a wide area network 6 such as the Internet, and is configured to be able to communicate with a management device 7 connected to the wide area network 6 in the same manner. The management device 7 centrally manages, for example, the status of power sales collected from the plurality of servers 4 by periodically exchanging information with the plurality of servers 4 connected to the wide area network 6.

  Hereinafter, an operation example of the power control system 10 of the present embodiment will be described with reference to FIG. Here, a case where the server 4 transmits a power sale permission in the order of the customer 11, the customer 12, and the customer 13 to the consumers 11 to 13 in the same bank will be described as an example. 6 indicates a time zone during which the control unit 27 is communicating.

  The server 4 transmits a power sale permission by communication to the control unit 27 of the customer 11 during the first communication period (time t1 to t2) in FIG. At this time, since the control unit 27 of the consumer 11 is in a state where power can be sold (with surplus power), the control unit 27 returns permission acceptance to the server 4 and power condition during the power sale period (time t2 to t3) immediately after that. The output voltage of the na 22 is increased and surplus power is sold from the consumer 11.

  When the power sale period for selling power from the consumer 11 is completed, the server 4 communicates a power sale permission to the control unit 27 of the next consumer 12 by communication in the communication period (time t3 to t4) immediately after that. Send. At this time, the control unit 27 of the customer 12 returns a permission decline to the server 4 because the power is not sold (no surplus power). The server 4 that has received a reply of permission decline transmits a power sale permission by communication to the control unit 27 of the next consumer 13 during the same communication period (time t3 to t4). At this time, since the control unit 27 of the consumer 13 is in a state in which power can be sold (with surplus power), it returns a permission acceptance to the server 4 and power condition during the power sale period immediately after (time t4 to t5). The output voltage of the N 22 is increased and surplus power is sold from the consumer 13.

  When the power sale period for selling power from the consumer 13 ends, the server 4 communicates power sale permission to the control unit 27 of the next consumer 11 by communication in the communication period (time t5 to t6) immediately after that. Send. At this time, since the control unit 27 of the customer 11 is in a state where power sale is not possible (no surplus power), it returns a permission decline to the server 4. The server 4 that has received a reply of permission decline transmits a power sale permission by communication to the control unit 27 of the next consumer 12 during the same communication period (time t5 to t6). At this time, since the control unit 27 of the customer 12 is in a state in which power can be sold (with surplus power), the control unit 27 returns permission acceptance to the server 4 and power condition during the immediately subsequent power selling period (time t6 to t7). The output voltage of the power supply 22 is increased to sell surplus power from the customer 12.

  According to the configuration described above, a plurality of customers (customers common to the transformer 31) 1 in the same bank have a power sale period for selling surplus power separated by the server 4 by a predetermined length. Will be assigned sequentially. In short, a plurality of consumers 1 in the same bank receive an opportunity to sell surplus power by receiving the power sale permission from the server 4 by the control unit 27 regardless of the positional relationship with the transformer 31. Will be. Therefore, even when the solar cells 20 are installed in the plurality of consumers 1 in the same bank, the plurality of consumers 1 can be distributed to the plurality of consumers 1 without any variation in the opportunities for selling power. This will give equal opportunities to sell electricity.

  By the way, the power control system 10 is not limited to the configuration in which each of the plurality of consumers 1 has an opportunity to sell power one by one as described above, but the server 4 monitors the system voltage, and according to the magnitude of the system voltage. The structure which determines the number of the houses of the consumer 1 which gives the opportunity of power sale simultaneously may be sufficient.

  That is, when the system voltage is high and close to the output upper limit of the power conditioner 22, if a plurality of consumers 1 sells power all at once, the voltage on the secondary side of the transformer 31 rises, making it impossible to sell power. If the system voltage is low, a plurality of customers 1 can sell power all at once. Focusing on this point, the server 4 determines the number of customer 1s that are allowed to sell power at the same time as the grid voltage decreases, so that the number of customer 1s that give an opportunity to sell power increases at the same time. You may determine according to a magnitude | size. Specifically, when the system voltage fluctuates within a predetermined range (for example, a range of 101 ± 6V), the server 4 sells simultaneously as the system voltage becomes lower than the upper limit value (here, 107V) as shown in FIG. Increase the number of customers 1 that give out electric permission.

  According to this configuration, even in the case of the consumer 1 in the same bank, the opportunity for selling power is given to each house 1 at a time when the system voltage is low. There is an advantage that it can be increased and the efficiency of power sale is improved.

  Other configurations and functions are the same as those of the first embodiment.

  By the way, in each said embodiment, since the control part 27 (or control part 27 and the server 4) of each consumer 1 comprises the node of a communication system, by utilizing this communication system, of the commercial electric power system | strain The single operation of the solar cell 20 can be reliably prevented during a power failure.

  That is, when each consumer 1 is provided with a protection device for preventing independent operation as described above, when solar cells 20 are installed in a plurality of consumers 1 in the same bank, the power condition is set. There is a possibility that the two terminals 22 misidentify each other as a commercial power system. In short, at the time of a power failure in the commercial power system, the power conditioner 22 of a certain consumer 1 mistakenly recognizes the output of the power conditioner 22 of another customer 1 as a commercial power system, and this causes the commercial power system to fail. There is a possibility of making a false decision that the user has not done so. In this case, since the inverter circuit does not stop, power is supplied to the secondary side of the transformer 31.

  On the other hand, in the power control system 10 of each of the embodiments described above, by providing a notification unit (not shown) for notifying all customers 1 in the same bank of the power failure when the commercial power system fails. In addition, single operation of the solar cell 20 can be reliably prevented. The notification unit is provided in at least one of the control unit 27 and the server 4 of each customer 1. When the control unit 27 receives a power failure notification from the notification unit, the control unit 27 notifies the protection device of a power failure of the commercial power system, thereby preventing an isolated operation.

1, 11, 12, 13 Consumer 4 Server 10 Power control system 20 Solar cell (distributed power supply)
22 Power conditioner 25 Power meter 23 Storage battery (power storage unit)
27 Control Unit 28 Transmission / Reception Circuit Unit 31 Transformer

Claims (3)

Consisting of a plurality of consumers that pull in the commercial power system from a common transformer, the distributed power source that generates power, and the power generated by the distributed power source is converted into power that can be supplied to a load circuit, and the distributed When there is surplus power in the power generated by the power source, a power conditioner that sells power by flowing the surplus power back to the commercial power system is used for a consumer group equipped with each of a plurality of consumers Power control system,
Each of the plurality of consumers includes a control unit that controls the power conditioner to perform power sale over a predetermined length of power sale period,
A server configured to be able to communicate with each of the plurality of the control units;
The power control system, wherein the server allocates the power selling period to each of the plurality of control units according to a voltage level of the commercial power system.   2. The power control system according to claim 1, wherein the server increases the number of the control units that issue power sale permission at the same time as the voltage of the commercial power system decreases from an upper limit value.   A server used for the power control system according to claim 1 or 2.

Images