JP7554615B2 - Power System - Google Patents

Description

This disclosure relates to power systems.

Power systems that manage multiple power control devices connected to a power grid and control the transmission and reception of power between the power grid are becoming more widespread. For example, Patent Document 1 discloses an example of a power system equipped with multiple power control devices and a processing device. The processing device calculates an index (control command value) for controlling the connection point power to a target power. The connection point power is the power at the connection point between the power grid and the power system. The multiple power control devices are, for example, a solar power generation device and a storage battery control device. Each power control device controls the output power in a distributed manner using the control command value calculated by the processing device. At this time, each power control device calculates a target value for the output power based on an optimization problem using the control command value. Then, the output power is controlled so that the output power becomes the target value. In this way, energy management of the power system is performed.

JP 2020-43642 A

Due to the diversification of power control devices, types of power control devices other than solar power generation devices and storage battery control devices are being connected to the power grid. One example of such a power control device is a charger/discharger for electric vehicles (hereinafter referred to as an "EV stand"). EV is an abbreviation for Electric Vehicle. EV stands generally charge electric vehicles, but some also discharge electric vehicles. For example, in the event of a disaster or other such event where power cannot be supplied from the power company, the electric vehicle may be used as a power source to utilize the power stored in the electric vehicle. Therefore, energy management that includes charge/discharge control of electric vehicles is required, but the power system described in Patent Document 1 does not take into account power control including EV stands.

This disclosure was conceived in light of the above circumstances, and its purpose is to provide a power system that performs energy management, including charge and discharge control, for electric vehicles.

The power system of the present disclosure is a power system that is connected to a power grid and controls the connection point power, which is the power at the connection point with the power grid, and includes a detection device that detects the value of the connection point power, a processing device that derives an induced command value for making the value of the connection point power a set adjustment target value, and a plurality of power control devices that are each electrically connected to the connection point and control output power based on an optimization problem using the induced command value. The plurality of power control devices include a first charge/discharge control device to which a storage battery is connected and a second charge/discharge control device to which an electric vehicle can be connected. The first charge/discharge control device controls the charging/discharging of the storage battery, and the second charge/discharge control device controls the charging/discharging of the electric vehicle. When a communication abnormality occurs in any of the communication between the detection device and the processing device, the communication between the processing device and the first charge/discharge control device, and the communication between the processing device and the second charge/discharge control device, the second charge/discharge control device stops the charging/discharging of the electric vehicle and notifies the user that the communication abnormality has occurred.

In a preferred embodiment of the power system, the processing device transmits flag information specifying whether the electric vehicle can be charged and discharged to the second charge/discharge control device, and the second charge/discharge control device receives the flag information and controls the charging and discharging of the electric vehicle based on the induced command value and the received flag information, and the flag information is determined according to the control mode for the power control.

In a preferred embodiment of the power system, the power system further includes a three-winding transformer including a first winding, a second winding, and a third winding, the first winding being connected to the connection point, the second winding being connected to the first charge/discharge control device, and the third winding being connected to the second charge/discharge control device.

In a preferred embodiment of the power system, the processing device receives the output power of each of the power control devices from each of the multiple power control devices, and when the total value of the received output power exceeds the winding capacity of the first winding, the processing device transmits a setting value as the induction command value to each of the multiple power control devices to eliminate the excess.

In a preferred embodiment of the power system, the set value is a value that stops charging/discharging of the storage battery if the total value exceeds the winding capacity when power is being supplied from the connection point side to the three-winding transformer side, and is a value that stops charging/discharging of the electric vehicle if the total value exceeds the winding capacity when power is being supplied from the three-winding transformer side to the connection point side.

The power system of the present disclosure includes a processing device and a plurality of power control devices. The processing device calculates an induction command value for bringing the connection point power to a target power. The plurality of power control devices each control output power based on an optimization problem using the induction command value. The plurality of power control devices includes a second charge/discharge control device to which an electric vehicle can be connected. The second charge/discharge control device controls charging/discharging of the electric vehicle. According to this configuration, the second charge/discharge control device controls charging/discharging of the electric vehicle based on an optimization problem using the induction command value. Therefore, the power system of the present disclosure is capable of energy management, including charging/discharging control of the electric vehicle, by the second charge/discharge control device.

1 shows an overall configuration of a power system according to a first embodiment. 4 is an example of a characteristics graph showing the relationship between an induction command value and an output power of each power control device. 10 is another example of a characteristic graph showing the relationship between the induction command value and the output power of each power control device. 1 shows an overall configuration of a power system according to a second embodiment.

A preferred embodiment of the power system of the present disclosure will be described below with reference to the drawings. In the following description, identical or similar components will be given the same reference numerals and duplicate descriptions will be omitted.

Figure 1 shows the overall configuration of the power system S1 of this embodiment. The power system S1 includes a power line 90, a transformer 91, a circuit breaker 92, a processing device A1, multiple power control devices B1, a detection device C1, and a network hub H1. The multiple power control devices B1 include a storage battery charge/discharge control device 10 and multiple EV charge/discharge control devices 20. A storage battery 19 is connected to the storage battery charge/discharge control device 10. Multiple electric vehicles 29 can be connected to each of the multiple EV charge/discharge control devices 20. In this disclosure, the electric vehicle 29 refers to a vehicle that can run using an electric motor as a power source, and includes a fuel cell vehicle and a vehicle equipped with an internal combustion engine (e.g., a plug-in hybrid vehicle). The electric motor operates using power stored in a storage battery provided in the electric vehicle 29.

The power system S1 is connected to a connection point K and is interconnected with the power system D. The power system S1 is capable of transmitting power to the power system D (capable of reverse power flow) and receiving power from the power system D. In this disclosure, when power is being output from the power system S1 to the power system D, i.e., when reverse power flow is occurring, the connection point power is assumed to be a positive value. On the other hand, when power is being output from the power system D to the power system S1, the connection point power is assumed to be a negative value. The connection point power refers to the power at the connection point K between the power system S1 and the power system D.

In the power system S1, the processing device A1 and the multiple power control devices B1 cooperate to control the connection point power to the target power. The target power is the target value (adjustment target value) of the connection point power. In the power control of the power system S1, the processing device A1 calculates an index for controlling the connection point power to the target power (adjustment target value). This index corresponds to the control command value described in Patent Document 1, and is called an "induced command value" in this disclosure. Each power control device B1 calculates an output target value of the control object (storage battery 19 or each electric vehicle 29) based on the induced command value calculated by the processing device A1. Then, each power control device B1 controls the output power of the control object based on the calculated output target value. In this way, the power system S1 controls the connection point power to the target power (adjustment target value) by the multiple power control devices B1 controlling the output power in a distributed manner. The induced command value is also used by each power control device B1 to calculate the output target value.

The power loads L consume the power that is supplied to them. Power is supplied to the power loads L from the power system D and each power control device B1. The power loads L include general loads L1 and important loads L2. The general loads L1 include, for example, electrical equipment that is relatively unaffected even if the power is cut off during a disaster. The important loads L2 are important loads that require a continuous supply of power even during a disaster, and include, for example, emergency elevators, electrical equipment that requires continuous operation, and building lighting and air conditioning equipment.

The network hub H1 relays communication between the processing device A1 and each power control device B1, and between the processing device A1 and the detection device C1. Each communication between the network hub H1 and the processing device A1, each power control device B1, and the detection device C1 may be wireless communication or wired communication. Note that each device may communicate directly with each other without the network hub H1 relaying the communication between the devices.

The power lines 90 are used to construct a power network in the power system S1. Some of the power lines 90 connect the power system D to the power loads L (general loads L1 and important loads L2), some connect the power system D to the transformer 91, and some connect the transformer 91 to each power control device B1.

The transformer 91 is, for example, a three-phase, three-winding transformer. The transformer 91 has a first winding 911, a second winding 912, and a third winding 913. The first winding 911 is connected to a connection point K via a circuit breaker 92. The second winding 912 is connected to a storage battery charge/discharge control device 10. The third winding 913 is connected to a plurality of EV charge/discharge control devices 20. The voltage and power (apparent power) of the first winding 911 are, for example, 6600 V and 56 kVA. The voltage and power (apparent power) of the second winding 912 are, for example, 300 V and 56 kVA. The voltage and power (apparent power) of the third winding 913 are, for example, 210 V and 50 kVA. The winding capacity of each of the first winding 911, the second winding 912, and the third winding 913 is, for example, 50 kW. The voltage, power, and winding capacity of each of the first winding 911, the second winding 912, and the third winding 913 are not limited to these values. The transformer 91 may be configured not only as a three-winding transformer, but also as two two-winding transformers, a two-winding transformer connected between the connection point K and the storage battery charge/discharge control device 10, and a two-winding transformer connected between the connection point K and each of the multiple EV charge/discharge control devices 20. However, by using a three-winding transformer, it is possible to save space and reduce weight compared to the case of using two two-winding transformers.

The circuit breaker 92 is, for example, a VCB (vacuum circuit breaker). When an abnormality in the power system D is detected, the circuit breaker 92 cuts off the electric circuit. For example, the circuit breaker 92 cuts off when an abnormality such as a short circuit or power outage is detected on the power system D side by an UVR (undervoltage relay: not shown), when an earth fault is detected on the power system D by an OVGR (overvoltage earth relay: not shown), or when an abnormality such as reverse power flow to the power system D side or a short circuit is detected by an RPR/UPR (reverse power relay/underpower relay: not shown). When the circuit of the circuit breaker 92 is cut off, the important load L2 is separated from the power system D. At this time, the power system S1 performs an independent operation and supplies power to the important load L2 from the battery charge/discharge control device 10 and the EV charge/discharge control device 20.

The detection device C1 detects the connection point power. The detection device C1 includes a detection unit 81 and a communication processing unit 82. The detection unit 81 is installed at the connection point K between the power system S1 and the power system D, and detects the connection point power. The detection unit 81 is, for example, a power transducer. The detection unit 81 can communicate with the communication processing unit 82, and outputs the detection value of the connection point power to the communication processing unit 82. The communication processing unit 82 is an AD converter that converts the detection value (analog value) of the connection point power input from the detection unit 81 into a digital value, and transmits the detection value (digital value) of the connection point power after the conversion to the processing device A1 via the network hub H1. The detection device C1 is further equipped with various protective devices for connecting the power system S1 to the power system D as appropriate. For example, if the power system S1 is a system in which reverse power flow to the power system D is prohibited, the detection device C1 includes an RPR (reverse power relay) as a protective device. In addition, the detection device C1 may communicate directly with the processing device A1 without going through the network hub H1.

The processing device A1 can communicate with each of the multiple power control devices B1 and the detection devices C1 via the network hub H1. The processing device A1 monitors the connection point power and calculates an induction command value for controlling the connection point power to a target power (adjustment target value). The connection point power may be a detected value detected by the detection device C1, or may be an estimated value calculated from the value of each output power acquired by communication from each power control device B1. In addition, either the detected value or the estimated value is used as the connection point power according to a control mode described later. In addition, the target power (adjustment target value) is appropriately set in advance according to a control mode described later. For example, the target power may be a value previously set in the processing device A1, a value set by a user operation, a value instructed by a higher-level device (for example, a power company, etc.) according to the control mode. The processing device A1 transmits the calculated induction command value to each of the multiple power control devices B1 (the battery charge/discharge control device 10 and the EV charge/discharge control device 20). The processing device A1 is set with state equations (simultaneous differential equations) shown in the following formulas (1) and (2), for example, and calculates a guiding command value pr(t) by solving these state equations. The processing device A1 calculates the guiding command value every predetermined time (for example, 1 [sec]). In the following formulas (1) and (2), P(t) is the connection point power, P _C (t) is the target power, λ(t) is the state variable, pr(t) is the guiding command value, and ε is the gradient coefficient.

The processing device A1 is set with a control mode, similar to the power system described in Patent Document 1. The control mode is a setting that determines the system function of the power system S1. The control modes in the power system S1 include, for example, a schedule mode, a peak cut mode, a peak cut assistance mode, and an RPR avoidance mode, similar to the control modes described in Patent Document 1. In addition, they also include an independent operation mode and a DG linked mode. The independent operation mode is a mode intended to control the power supply to the important load L2 when the circuit of the circuit breaker 92 is interrupted. The DG linked mode is a mode intended to perform power control when a diesel generator is added.

A charge/discharge permission flag is set in the processing device A1. The charge/discharge permission flag includes a charge permission flag and a discharge permission flag. The charge permission flag is flag information indicating whether charging of the electric vehicle 29 is permitted or prohibited. When charging of the electric vehicle 29 is prohibited, the charge permission flag is set to a flag value of "0", while when charging of the electric vehicle 29 is permitted, the flag value of "1" is set. The discharge permission flag is flag information indicating whether discharging of the electric vehicle 29 is permitted or prohibited. When discharging of the electric vehicle 29 is prohibited, the flag value of "0" is set, while when discharging of the electric vehicle 29 is permitted, the flag value of "1" is set. In the processing device A1, a control mode is set in the same way as in the power system described in Patent Document 1, and the charge/discharge permission flag and the discharge permission flag are each set in advance according to the control mode set in the processing device A1. For example, in the schedule mode, the charge permission flag is set to a flag value of "1", and the discharge permission flag is set to a flag value of "0". In the peak cut mode, the charging permission flag is set to a flag value of "1", and the discharging permission flag is set to a flag value of "1". In the peak cut assistance mode, the charging permission flag is set to a flag value of "1", and the discharging permission flag is set to a flag value of "1". In the RPR avoidance mode, the charging permission flag is set to a flag value of "1", and the discharging permission flag is set to a flag value of "1". In the independent operation mode, the charging permission flag is set to a flag value of "0", and the discharging permission flag is set to a flag value of "1". However, in the independent operation mode, the charging permission flag may be appropriately changed according to a predetermined condition. In the DG linked mode, the charging permission flag is set to a flag value of "1", and the discharging permission flag is set to a flag value of "1". The setting values can be changed by a user's operation. For example, every time the setting of the control mode is changed, the processing device A1 transmits setting information of the charging/discharging permission flag (setting information of the charging permission flag and the discharging permission flag) to each EV charge/discharge control device 20. The setting information for the charge/discharge permission flag may be sent periodically, rather than every time the control mode setting is changed.

The battery charge/discharge control device 10 controls the charging and discharging of the battery 19. The battery charge/discharge control device 10 includes a battery power conditioner 11 and a communication processing unit 12. In this disclosure, the power conditioner is referred to as "PCS." The battery PCS 11 and the communication processing unit 12 communicate bidirectionally. The battery PCS 11 and the communication processing unit 12 are not limited to being configured as separate modules, and may be configured as a single module.

The communication processing unit 12 relays communication between the processing device A1 and the storage battery PCS11. The communication processing unit 12 receives a guidance command value from the processing device A1, and calculates an output target value of the storage battery PCS11 based on the received guidance command value. The method of calculating the output target value will be described later. The communication processing unit 12 generates a control command including the calculated output target value, and transmits this to the storage battery PCS11.

The storage battery PCS11 is connected to the storage battery 19 and charges and discharges the storage battery 19. In FIG. 1, one storage battery 19 is connected to the storage battery PCS11, but multiple storage batteries 19 may be connected. The storage battery 19 is, for example, a secondary battery or a capacitor. The storage battery PCS11 is connected to a second winding 912 of a transformer 91 by a power line 90. The storage battery PCS11 charges the storage battery 19 by supplying the power input from the transformer 91 to the storage battery 19. The storage battery PCS11 also discharges the storage battery 19 by outputting the power stored in the storage battery 19 to the transformer 91. The storage battery PCS11 controls the charge amount of the storage battery 19 and the discharge amount of the storage battery 19 based on a control command received from the communication processing unit 12, thereby controlling the output power of the controlled object (storage battery 19). Specifically, the storage battery PCS11 performs power control so that the output power of the storage battery 19 becomes the output target value included in the control command. When the output target value in the received control command is a positive value, the storage battery PCS11 discharges the storage battery 19. On the other hand, when the output target value in the received control command is a negative value, the storage battery PCS11 charges the storage battery 19.

The rated output of the storage battery PCS11 is, for example, 50 kW. In the example shown in FIG. 1, the power system S1 includes one storage battery charge/discharge control device 10, but the number of storage battery charge/discharge control devices 10 is not limited. However, the rated output and the number of storage battery charge/discharge control devices 10 (storage battery PCS11) are each set so that the total value of the rated output of the connected storage battery charge/discharge control devices 10 does not exceed the winding capacity of the second winding 912.

The storage battery PCS11 detects the value of the output power to the storage battery 19 and transmits this to the communication processing unit 12. The communication processing unit 12 receives the detected value of the output power from the storage battery PCS11 and transmits this to the processing device A1. The storage battery PCS11 also acquires the charging rate (SoC: State of Charge) of the storage battery 19 from the connected storage battery 19. The storage battery PCS11 transmits the charging rate of the storage battery 19 to the communication processing unit 12. The information on the charging rate of the storage battery 19 is used by the communication processing unit 12 to calculate the output target value.

Each of the multiple EV charge/discharge control devices 20 controls the charging and discharging of an electric vehicle 29. Each of the multiple EV charge/discharge control devices 20 includes an EV stand 21 and a communication processing unit 22. The EV stand 21 and the communication processing unit 22 perform two-way communication. The EV stand 21 and the communication processing unit 22 are not limited to being configured as separate modules, and may be configured as a single module.

Each of the multiple communication processing units 22 relays communication between the processing device A1 and each EV stand 21. Each communication processing unit 22 receives a guidance command value from the processing device A1, and calculates an output target value for each EV stand 21 based on the received guidance command value. The method of calculating the output target value will be described later. Each communication processing unit 22 generates a control command including the calculated output target value, and transmits this to each EV stand 21.

Each of the EV stands 21 is connected to an electric vehicle 29 and charges and discharges the electric vehicle 29 (specifically, charges and discharges a storage battery provided in the electric vehicle 29). In FIG. 1, one electric vehicle 29 is connected to the EV stand 21, but multiple electric vehicles 29 may be connected. Each EV stand 21 is connected to a third winding 913 of a transformer 91 by a power line 90. Each EV stand 21 charges each electric vehicle 29 by supplying the power input from the transformer 91 to each electric vehicle 29. Each EV stand 21 also discharges each electric vehicle 29 by outputting the power stored in each electric vehicle 29 to the transformer 91. Each EV stand 21 controls the output power of the control target (each electric vehicle 29) by controlling the charge amount of each electric vehicle 29 and the discharge amount of each electric vehicle 29 based on the control command received from each communication processing unit 22. Specifically, each EV stand 21 performs power control so that the output power of each electric vehicle 29 becomes the output target value included in the control command. Each EV stand 21 discharges each electric vehicle 29 when the output target value in the received control command is a positive value. On the other hand, each EV stand 21 charges each electric vehicle 29 when the output target value in the received control command is a negative value.

The rated output of each of the multiple EV stands 21 is, for example, 10 kW. In the example shown in FIG. 1, the power system S1 includes five EV charge/discharge control devices 20, but the number of EV charge/discharge control devices 20 is not limited. However, the rated output and number of the EV charge/discharge control devices 20 (EV stands 21) are set so that the total value of the rated output of the EV charge/discharge control devices 20 does not exceed the winding capacity of the third winding 913. In this embodiment, when multiple EV stands 21 with a winding capacity of 50 kW and a rated output of 10 kW are used, up to five EV stands 21 can be connected to the third winding 913.

Each EV stand 21 detects the value of the output power to the electric vehicle 29 and transmits it to each communication processing unit 22. Each communication processing unit 22 receives the detected value of the output power from each EV stand 21 and transmits it to the processing device A1. Each EV stand 21 also obtains the charging rate (SoC) of the electric vehicle 29 connected to it from that electric vehicle 29. Each EV stand 21 transmits the charging rate of each electric vehicle 29 to each communication processing unit 22. Information on the charging rate of the electric vehicle 29 is used by each communication processing unit 22 to calculate the output target value.

Each EV stand 21 is equipped with a notification device such as a display (not shown) or a speaker (not shown). Each EV stand 21 notifies information related to charging and discharging or abnormalities in the power system S1 by using the notification device (for example, display on the display or audio output from the speaker). Information related to charging and discharging includes, for example, the operating status of the EV stand 21 (preparing for charging/discharging, preparation complete, charging/discharging, charging/discharging complete, etc.), the state of charge (SoC) of the storage battery of the electric vehicle 29, the time required for full charging, the remaining time until full charging, the amount that can be discharged, and the fee for charging and discharging. This allows the power system S1 to notify the user of the charging status of each electric vehicle 29 and abnormalities in the power system S1 via each EV stand 21. Notification to the user or administrator is not limited to using a display or a speaker, and may be sent to a terminal device used by the user or administrator via wireless communication.

Next, the method of calculating the output target value performed by each power control device B1 (specifically, each of the communication processing unit 12 and the multiple communication processing units 22) will be described. Each of the communication processing unit 12 and the multiple communication processing units 22 calculates the output target value based on a preset optimization problem using the guidance command value received from the processing device A1. This optimization problem includes an evaluation function and constraint conditions.

The communication processing unit 12 and the multiple communication processing units 22 are set with the following arithmetic expressions (3) and (4) derived from the set evaluation function, and calculate the output target value P ^ref by these arithmetic expressions. In the following arithmetic expressions (3) and (4), P ^ref is the output target value of each of the communication processing units 12 and the multiple communication processing units 22, pr is the induction command value, pr ^lmt is the induction command value limit, and a ₁ to a ₄ are each design parameters. The induction command value limit pr ^lmt is a value that defines the maximum and minimum values of the induction command value pr used in the power system S1. The value Λ calculated by the following arithmetic expression (4) is limited to a value between the minimum value (-pr ^lmt ) of the induction command value pr and the maximum value (pr ^lmt ) of the induction command value pr. The design parameter a ₁ is a parameter that mainly adjusts the amount of change in the output power corresponding to the change in the induction command value pr. The design parameter _a2 is a parameter that mainly adjusts the output power when the induction command value pr is near 0. The design parameter _a3 is a parameter that mainly adjusts the induction command value pr at which the output power starts to change. The design parameter _a4 is a parameter according to the state of charge (SoC) of the connected storage battery 19 or the state of charge (SoC) of the connected electric vehicle 29. These design parameters _a1 to _a4 are set in the communication processing unit 12 and the multiple communication processing units 22, respectively. The communication processing unit 12 and the multiple communication processing units 22 may calculate the output target value P ^ref by solving a set evaluation function instead of the calculation formula shown in the following formula (3) and formula (4). The evaluation function is the same as that described in Patent Document 1, for example.

When the output target value P ^ref calculated by the arithmetic expressions (3) and (4) does not satisfy the constraint conditions set in the communication processing unit 12 and the communication processing units 22, the communication processing unit 12 and the communication processing units 22 correct the output target value so as to satisfy the constraint conditions. The constraint conditions set in the communication processing unit 12 include a rated output constraint, a remaining amount constraint, a C rate constraint, and an output current constraint (or a rated capacity constraint). The constraint conditions set in each communication processing unit 22 include a rated output constraint, a charge/discharge permission flag constraint, and an output current constraint (or a rated capacity constraint). For example, in the rated output constraint, when the calculated output target value P ^ref exceeds the rated output of the communication processing unit 12 or each rated output of the communication processing units 22, the output target value P ^ref is corrected to the value of the rated output. In addition, the charge/discharge permission flag constraint restricts the electric vehicle 29 from being charged or restricts the electric vehicle 29 from being discharged depending on the setting information of the charge/discharge permission flag (each setting information of the charge permission flag and the discharge permission flag) received from the processing device A1.

In the power system S1, the settings of the above design parameters _a1 to _a4 and the constraint conditions are appropriately adjusted so that the relationship between the induced command value and the output power of each power control device B1 has the characteristics shown in Fig. 2, for example. In Fig. 2, the vertical axis represents the output power, and the horizontal axis represents the induced command value. In Fig. 2, the change characteristic of the output power of the storage battery charge/discharge control device 10 is shown by a dashed line, the change characteristic of the total of the output powers of the multiple EV charge/discharge control devices 20 is shown by a dashed double-dashed line, and the change characteristic of the output power of the storage battery charge/discharge control device 10 and the total value of the output powers of the multiple EV charge/discharge control devices 20 is shown by a solid line.

In the example shown in FIG. 2, the battery charge/discharge control device 10 discharges the battery 19 when the induction command value is smaller than 0 (zero), and charges the battery 19 when the induction command value is larger than 0 (zero). At this time, the smaller the induction command value is 0 (zero), the greater the discharge amount becomes linearly larger, and the greater the induction command value is 0 (zero), the greater the charge amount becomes linearly larger. Furthermore, when the induction command value is 0 (zero), the battery charge/discharge control device 10 does not charge or discharge the battery 19. When the induction command value is smaller than -50, each EV charge/discharge control device 20 discharges each electric vehicle 29, and when the induction command value is larger than -50, each electric vehicle 29 is charged. At this time, the smaller the induction command value is -50, the greater the discharge amount becomes linearly larger, and the greater the induction command value is -50, the greater the charge amount becomes linearly larger. However, because the winding capacity of the third winding 913 is 50 kW, the total output power of the multiple EV charge/discharge control devices 20 is limited so as not to become smaller than -50 kW. In the example shown in FIG. 2, when the induction command value is 0 (zero), the total output power of the multiple EV charge/discharge control devices 20 is -50 kW, so when the induction command value is 0 (zero) or greater, it remains constant at -50 kW. Furthermore, when the induction command value is -50, each EV charge/discharge control device 20 neither charges nor discharges each electric vehicle 29.

In the power system S1, when the total value of the output powers received from each of the multiple power control devices B1 (the battery charge/discharge control device 10 and the multiple EV charge/discharge control devices 20) exceeds the winding capacity of the first winding 911, the processing device A1 transmits a set value (excess elimination set value) for eliminating the excess as an induction command value to each of the multiple power control devices B1 (the battery charge/discharge control device 10 and the multiple EV charge/discharge control devices 20). Note that the transmission of the excess elimination set value may be performed not only when the total value of the output powers of the multiple power control devices B1 exceeds the winding capacity of the first winding 911, but also when the total value exceeds a value slightly smaller than the winding capacity of the first winding 911. However, in a configuration in which an excess resolution setting value is transmitted as an induction command value when the total value of the output powers of the multiple power control devices B1 exceeds the winding capacity of the first winding 911, it is desirable to use a transformer 91 that can operate for at least several minutes even if the power in the first winding 911 exceeds the winding capacity of the first winding 911. The winding capacity of the first winding 911 may be exceeded when power is supplied from the first winding 911 to the connection point K (excessive discharge state), or when power is supplied from the connection point K to the first winding 911 (excessive charge state). In the excess discharge state, the excess resolution setting value is a value that stops charging and discharging of each electric vehicle 29. In the example shown in FIG. 2, when the winding capacity of the first winding 911 is 50 kW and the induction command value is smaller than about -65, the discharge-time excess state occurs, and the processing device A1 transmits, for example, -50 as the induction command value to each power control device B1. The excess-resolution set value (induction command value) in the discharge-time excess state is not limited to -50, and may be any value that resolves the discharge-time excess state. For example, in the example shown in FIG. 2, if the excess-resolution set value (induction command value) in the discharge-time excess state is a value greater than -65, the discharge-time excess state can be resolved. In the charge-time excess state, the excess-resolution set value is a value that stops charging and discharging the storage battery 19. In the example shown in FIG. 2, when the winding capacity of the first winding 911 is 50 kW and the induction command value is greater than 0 (zero), the charge-time excess state occurs, and the processing device A1 transmits, for example, 0 (zero) as the induction command value to each power control device B1. In addition, the excess resolution set value (induction command value) in the charging excess state is not limited to 0 (zero) and may be any value that can resolve the charging excess state. For example, in the example shown in FIG. 2, the excess resolution set value (induction command value) in the charging excess state can resolve the charging excess state if it is a value smaller than 0 (zero). After transmitting the excess resolution set value, the processing device A1 resumes transmitting the induction command value calculated by the calculation of the above formulas (1) and (2) after a certain time has elapsed.

The above-mentioned discharge excess state and the above-mentioned charge excess state will be described in the case where the characteristics shown in FIG. 3 are different from those shown in FIG. 2. For example, in the power system S1, if there are three EV charge/discharge control devices 20 instead of five, the characteristics shown in FIG. 3 will be obtained. In FIG. 3, the change characteristic of the output power of the battery charge/discharge control device 10 is shown by a dashed line, the change characteristic of the total of the output powers of the multiple EV charge/discharge control devices 20 is shown by a two-dot dashed line, and the change characteristic of the output power of the battery charge/discharge control device 10 and the total value of the output powers of the multiple EV charge/discharge control devices 20 is shown by a solid line. In the example shown in FIG. 3, when the induction command value is smaller than about -75, the discharge excess state occurs, and the processing device A1 transmits -50 as the induction command value to each power control device B1. Note that, even in the example shown in FIG. 3, the excess elimination set value (induction command value) in the discharge excess state is not limited to -50, and may be any value that eliminates the discharge excess state. Furthermore, if the induction command value is greater than 40, the charging excess state is reached, and the processing device A1 transmits an induction command value of 0 (zero) to each power control device B1. Note that, even in the example shown in FIG. 3, the excess resolution set value (induction command value) in the charging excess state is not limited to 0 (zero) and may be any value that resolves the charging excess state. In this way, the excess resolution set value is set appropriately according to the relationship between the induction command value and the output power of each power control device B1.

Next, we will explain what happens when communication between devices in the power system S1 is not performed normally. For example, situations in which communication is not performed normally include when a communication interruption occurs between devices or between elements within each device, or when a signal abnormality occurs between devices or between elements within each device.

<Case 1: Communication Abnormality Between Processing Device A1 and Detection Device C1>
When a communication abnormality occurs between the processing device A1 and the detection device C1 (communication processing unit 82), the processing device A1 cannot correctly receive the detection value of the connection point power from the detection device C1. As a result, the processing device A1 may not be able to properly calculate the induction command value, and the power system S1 may not be able to properly control the power.

Therefore, when the processing device A1 cannot correctly receive the detection value of the connection point power from the detection device C1, it transmits a set value (abnormal setting value) according to the control mode as an induction command value to each power control device B1. For example, when the peak cut mode is set, the abnormal setting value is a value that stops charging and discharging the storage battery 19. In the example shown in FIG. 2, the abnormal setting value for the peak cut mode is 0 (zero). Also, when the RPR avoidance mode is set, it is a value that charges the storage battery 19. In the example shown in FIG. 2, the abnormal setting value for the RPR avoidance mode is greater than 0 (zero) and less than or equal to 100. Note that, depending on the set control mode, the detection value of the detection device C1 may not be used as the connection point power. For example, in the schedule mode, the independent operation mode, and the DG linkage mode, power control is performed using an estimated value as the connection point power. Also, in the peak cut assistance mode, power control is performed according to a signal from a demand monitoring device (not shown). In this case, normal processing according to each control mode is performed without transmitting the abnormal setting value as an induction command value to each power control device B1. Furthermore, if the processing device A1 is unable to correctly receive the connection point power value from the detection device C1, it turns on a system abnormality flag indicating that a communication abnormality has occurred between the detection device C1 (or the communication processing unit 82). Then, it transmits a notification indicating that the system abnormality flag is on (system abnormality flag on notification) to each EV charge/discharge control device 20. When each EV charge/discharge control device 20 receives the system abnormality flag on notification, the EV stand 21 of that EV charge/discharge control device 20 stops charging/discharging the electric vehicle 29 and notifies the user that a communication abnormality has occurred between the processing device A1 and the detection device C1 (or the communication processing unit 82).

<Case 2: Communication Abnormality Between Processing Device A1 and Each Power Control Device B1>
In the power system S1, one-way communication and two-way communication may be used for communication between the processing device A1 and each power control device B1. One-way communication is performed, for example, by UDP communication. One-way communication is used when transmitting an induction command value from the processing device A1 to each power control device B1. Two-way communication is performed, for example, by Modbus communication. Two-way communication is used when transmitting a detection value of output power from each power control device B1 to the processing device A1. Therefore, in the power system S1, communication abnormalities may occur in one-way communication and communication abnormalities may occur in two-way communication, and each case will be described below.

<Case 2-1: When a communication error occurs in one-way communication>
When a communication error occurs in the one-way communication, each power control device B1 cannot correctly receive the induction command value from the processing device A1. As a result, each power control device B1 cannot correctly calculate the output target value and cannot appropriately control the output power.

Therefore, the battery charge/discharge control device 10 stops charging/discharging the battery 19 if it cannot correctly receive the induced command value from the processing device A1. Also, each EV charge/discharge control device 20 stops charging/discharging each electric vehicle 29 if it cannot correctly receive the induced command value from the processing device A1. As a result, when a communication abnormality occurs in the one-way communication, charging/discharging of the battery 19 is stopped, and charging/discharging of each electric vehicle 29 is stopped. Furthermore, when the battery charge/discharge control device 10 cannot correctly receive the induced command value from the processing device A1, it transmits a first one-way communication abnormality notification to the processing device A1 by two-way communication. When the processing device A1 receives the first one-way communication abnormality notification, it turns on the first one-way communication abnormality flag. Then, it transmits a notification indicating that the first one-way communication abnormality flag is on (first one-way communication abnormality flag on notification) to each EV charge/discharge control device 20 by two-way communication. Each EV charge/discharge control device 20 that has received the first one-way communication abnormality flag ON notification notifies the EV stand 21 that an abnormality has occurred in the one-way communication between the processing device A1 and the storage battery charge/discharge control device 10. This allows a user or manager to know that an abnormality has occurred in the one-way communication between the processing device A1 and the storage battery charge/discharge control device 10 via each EV stand 21. Furthermore, when each EV charge/discharge control device 20 is unable to correctly receive an induction command value from the processing device A1, it transmits a second one-way communication abnormality notification to the processing device A1 by bidirectional communication. When the processing device A1 receives the second one-way communication abnormality notification, it turns on the second one-way communication abnormality flag. Then, it transmits a notification indicating that the second one-way communication abnormality flag is ON (second one-way communication abnormality flag ON notification) to each EV charge/discharge control device 20 by bidirectional communication. Each EV charge/discharge control device 20 that receives the second one-way communication abnormality flag-on notification notifies the EV stand 21 that an abnormality has occurred in the one-way communication between the processing device A1 and the other EV charge/discharge control device 20. This allows the user or administrator to know, via each EV stand 21, that an abnormality has occurred in the one-way communication between the processing device A1 and the storage battery charge/discharge control device 10.

<Case 2-2: When a communication error occurs during two-way communication>
When a communication abnormality occurs in the two-way communication, the processing device A1 cannot correctly receive the detection value of the output power from each power control device B1. As a result, the processing device A1 can only use the detection value of the output power that has been correctly received. In other words, the processing device A1 may not be able to calculate an appropriate induction command value, and therefore the power control of the power system S1 may not be performed appropriately.

Therefore, each power control device B1 in which a communication abnormality occurs with the processing device A1 stops charging and discharging the controlled object (storage battery 19 or electric vehicle 29). For example, if a communication abnormality occurs in the two-way communication between the processing device A1 and the storage battery charge/discharge control device 10, the storage battery charge/discharge control device 10 stops charging and discharging the storage battery 19. On the other hand, if a communication abnormality occurs in the two-way communication between the processing device A1 and each EV charge/discharge control device 20, each EV charge/discharge control device 20 stops charging and discharging the respective electric vehicles 29. As a result, when a communication abnormality occurs in the above two-way communication, the charging and discharging of the controlled object (storage battery 19 or each electric vehicle 29) is stopped in each power control device B1 in which a communication abnormality occurs with the processing device A1.

Furthermore, the occurrence of a communication abnormality between the processing device A1 and each power control device B1 is notified to a user or administrator via each EV stand 21. For example, when a communication abnormality occurs in the two-way communication between the processing device A1 and the storage battery charge/discharge control device 10, the processing device A1 turns on the first two-way communication abnormality flag and transmits a notification indicating that the first two-way communication abnormality flag is on (first two-way communication abnormality flag on notification) to each EV charge/discharge control device 20. Each EV charge/discharge control device 20 that receives the first two-way communication abnormality flag on notification causes each EV stand 21 to notify that a communication abnormality has occurred in the two-way communication between the processing device A1 and the storage battery charge/discharge control device 10. This allows a user or administrator to know that an abnormality has occurred in the two-way communication between the processing device A1 and the storage battery charge/discharge control device 10 via each EV stand 21. On the other hand, if a communication abnormality occurs in the two-way communication between the processing device A1 and any one of the multiple EV charge/discharge control devices 20, the EV charge/discharge control device 20 in which the communication abnormality occurs causes the EV stand 21 to notify the EV charge/discharge control device 20 in which the communication abnormality occurs with the processing device A1. The processing device A1 also turns on the second two-way communication abnormality flag and transmits a notification indicating that the second two-way communication abnormality flag is on (second two-way communication abnormality flag on notification) to the EV charge/discharge control device 20 in which no communication abnormality occurs. Then, the EV charge/discharge control device 20 that receives the second two-way communication abnormality flag on notification causes the EV stand 21 to notify the EV charge/discharge control device 20 in which the communication abnormality occurs between the other EV charge/discharge control device 20 and the processing device A1. This allows the user or administrator to know, via each EV stand 21, that an abnormality has occurred in the two-way communication between the processing device A1 and the EV charge/discharge control device 20.

<Case 3: Communication Abnormality Between Storage Battery PCS 11 and Communication Processing Unit 12>
When a communication abnormality occurs between the storage battery PCS11 and the communication processing unit 12, the storage battery PCS11 cannot correctly receive the output target value from the communication processing unit 12. As a result, the storage battery PCS11 does not know the target power value (output target value) and cannot properly control the output power. In addition, the communication processing unit 12 cannot correctly receive the detection value of the output power and the SoC of the storage battery 19 from the storage battery PCS11. As a result, the communication processing unit 12 cannot correctly receive the detection value of the output power, and therefore cannot transmit the detection value of the output power to the processing device A1, and the processing device A1 may not properly calculate the induction command value. In addition, the communication processing unit 12 may not correctly calculate the output target value, and therefore cannot receive the SoC of the storage battery 19.

Therefore, if the storage battery PCS11 cannot correctly receive the output target value from the communication processing unit 12, it stops charging and discharging the storage battery 19. As a result, if a communication abnormality occurs between the storage battery PCS11 and the communication processing unit 12, charging and discharging of the storage battery 19 is stopped. Also, if the communication processing unit 12 cannot correctly receive the output power value or the SoC information of the storage battery 19 from the storage battery PCS11, it transmits a first internal abnormality notification to the processing device A1. When the processing device A1 receives the first internal abnormality notification, it turns on the first internal abnormality flag. Then, it transmits a notification indicating that the first internal abnormality flag is on (first internal abnormality flag on notification) to each EV charge and discharge control device 20. At this time, the communication between the processing device A1 and the EV charge and discharge control device 20 may be one-way communication or two-way communication. Each EV charge and discharge control device 20 that receives the first internal abnormality flag on notification notifies the EV stand 21 that a communication abnormality has occurred inside the storage battery charge and discharge control device 10. This allows the user or administrator to know that a communication abnormality has occurred inside the storage battery charge/discharge control device 10. The communication processing unit 12 may transmit the first internal abnormality notification to each EV charge/discharge control device 20 instead of the processing device A1. In this case, each EV charge/discharge control device 20 that receives the first internal abnormality notification notifies the EV stand 21 that a communication abnormality has occurred inside the storage battery charge/discharge control device 10.

<Case 4: Communication Abnormality Between the EV Stand 21 and the Communication Processing Unit 22>
In each EV charge/discharge control device 20, when a communication abnormality occurs between the EV stand 21 and the communication processing unit 22, the EV stand 21 cannot correctly receive the output target value from the communication processing unit 22. In this case, the EV stand 21 does not know the target power value (output target value) and cannot properly control the output power. In addition, the communication processing unit 22 cannot correctly receive the detection value of the output power and the SoC of the electric vehicle 29 from the EV stand 21. As a result, since the communication processing unit 22 cannot correctly receive the detection value of the output power, it cannot transmit the detection value of the output power of the EV stand 21 to the processing device A1, and the processing device A1 may not properly calculate the induction command value. In addition, since the communication processing unit 22 cannot receive the SoC of the electric vehicle 29 from the EV stand 21, it may not properly calculate the output target value.

Therefore, in the EV charge/discharge control device 20 in which a communication abnormality occurs between the EV stand 21 and the communication processing unit 22, the EV stand 21 stops charging/discharging the electric vehicle 29 if it cannot correctly receive the output target value from the communication processing unit 22. As a result, in the EV charge/discharge control device 20 in which a communication abnormality occurs between the EV stand 21 and the communication processing unit 22, charging/discharging of the electric vehicle 29 is stopped. Furthermore, the EV stand 21 notifies the EV charge/discharge control device 20 of the occurrence of a communication abnormality through the notification device. If the communication processing unit 22 cannot correctly receive the output power value or the SoC information of the electric vehicle 29 from the EV stand 21, it transmits a second internal abnormality notification to the processing device A1. When the processing device A1 receives the second internal abnormality notification, it turns on the second internal abnormality flag. Then, it transmits a notification indicating that the second internal abnormality flag is on (second internal abnormality flag on notification) to each EV charge/discharge control device 20. Each EV charge/discharge control device 20 that receives the second internal abnormality flag ON notification notifies the other EV charge/discharge control device 20 from the EV stand 21 that a communication abnormality has occurred inside the EV charge/discharge control device 20. However, as described above, the EV charge/discharge control device 20 in which the communication abnormality has occurred is notified of the abnormality by the processing of the EV stand 21. This allows the user or administrator to know that a communication abnormality has occurred inside one of the multiple EV charge/discharge control devices 20. Note that the communication processing unit 22 of the EV charge/discharge control device 20 in which the communication abnormality has occurred may transmit the second internal abnormality notification to the other EV charge/discharge control device 20 instead of the processing device A1. In this case, each EV charge/discharge control device 20 that receives the second internal abnormality notification notifies the other EV charge/discharge control device 20 from the EV stand 21 that a communication abnormality has occurred inside the EV charge/discharge control device 20.

The functions and effects of the power system S1 are as follows:

The power system S1 includes a processing device A1 and multiple power control devices B1. The processing device A1 calculates an induced command value for making the connection point power a target power. The multiple power control devices B1 each control output power based on an optimization problem using the induced command value. The multiple power control devices B1 include an EV charge/discharge control device 20 to which an electric vehicle 29 can be connected. According to this configuration, the EV charge/discharge control device 20 controls the charging and discharging of the electric vehicle 29 based on an optimization problem using the induced command value. Therefore, the power system S1 is capable of energy management, including the charging and discharging control of the electric vehicle 29, by the EV charge/discharge control device 20.

In the power system S1, when a communication abnormality occurs in any of the communication between the detection device C1 and the processing device A1, the communication between the processing device A1 and the battery charge/discharge control device 10, and the communication between the processing device A1 and each EV charge/discharge control device 20, each EV charge/discharge control device 20 stops charging/discharging each electric vehicle 29 and notifies the occurrence of the communication abnormality. The processing device A1 and the battery charge/discharge control device 10, and the processing device A1 and each EV charge/discharge control device 20 each communicate via a network hub H1. If a communication abnormality occurs in any of the above-mentioned communications, the EV charge/discharge control device 20 may not be able to properly charge/discharge the electric vehicle 29, and unintended charging/discharging may occur. For example, there is a possibility that the electric vehicle 29 that should not be discharged is discharged. Therefore, in the power system S1, if a communication abnormality occurs in any of the above-mentioned communications, the charging/discharging of the electric vehicle 29 is stopped, thereby suppressing unintended charging/discharging of the electric vehicle 29. Furthermore, in the power system S1, the EV charge/discharge control device 20 notifies the user of the EV charge/discharge control device 20 (EV stand 21) of the occurrence of a communication abnormality, so that the user of the EV charge/discharge control device 20 (EV stand 21) can be informed of the occurrence of the communication abnormality. In particular, unlike conventional power systems (described in Patent Document 1), the power system S1 does not have a terminal device dedicated to the administrator, and is therefore unable to notify the administrator of the occurrence of a communication abnormality in real time. Therefore, by having an alarm device provided in the EV stand 21 notify the user of the EV stand 21 that an abnormality has occurred. This encourages the user to provide information about the communication abnormality to the administrator, enabling the administrator to discover the communication abnormality early.

In the power system S1, the processing device A1 transmits setting information for the charge/discharge permission flag (setting information for the charge permission flag and the discharge permission flag) to each EV charge/discharge control device 20. The charge/discharge permission flag is determined according to the control mode that is set. The operation of the EV charge/discharge control device 20 (EV stand 21) may involve only charging, only discharging, or both charging and discharging. These operations change according to the control mode. Therefore, in the power system S1, the charge/discharge permission flag is changed according to the control mode, so that the charging and discharging of the electric vehicle 29 by the EV charge/discharge control device 20 can be appropriately controlled.

In the power system S1, when the total value of the output power of the multiple power control devices B1 (the battery charge/discharge control device 10 and the multiple EV charge/discharge control devices 20) exceeds the winding capacity of the first winding 911 (or exceeds a value slightly smaller than the winding capacity), the processing device A1 transmits a set value (excess elimination set value) for eliminating the excess as an induction command value to each of the multiple power control devices B1. According to this configuration, when the power in the first winding 911 exceeds the winding capacity of the first winding 911, the excess elimination set value is transmitted to each power control device B1 as an induction command value. Then, each power control device B1 controls the output power based on the received induction command value (excess elimination set value), so that the state in which the winding capacity of the first winding 911 is exceeded is eliminated. In other words, the power system S1 can suppress failure of the transformer 91 (failure of the first winding 911).

In the power system S1, when the total value of the output power of the multiple power control devices B1 exceeds the winding capacity of the first winding 911 in a state where power is supplied from the connection point K to the transformer 91 (excessive charging state), the excess elimination set value is a value that stops charging and discharging of the storage battery 19. On the other hand, when the total value of the output power of the multiple power control devices B1 exceeds the winding capacity of the first winding 911 in a state where power is supplied from the transformer 91 to the connection point K (excessive discharging state), the excess elimination set value is a value that stops charging and discharging of each electric vehicle 29. In this way, the power system S1 can eliminate the situation where the total value of the output power of the multiple power control devices B1 exceeds the winding capacity of the first winding 911.

Figure 4 shows the overall configuration of the power system S2 of the second embodiment. As shown in Figure 4, compared to the power system S1, the power system S2 has a PV output control device 30 instead of one EV charge/discharge control device 20. PV is an abbreviation for Photovoltaics (photovoltaic power generation).

The PV output control device 30 controls power generation by the solar cell 39. The PV output control device 30 includes a solar PCS 31, a communication processing unit 32, and a detection unit 33. The solar PCS 31 and the communication processing unit 32 perform bidirectional communication. The solar PCS 31 and the communication processing unit 32 are not limited to being configured as separate modules, and may be configured as a single module.

The detection unit 33 detects the output power of the solar PCS 31. Then, the detection value (analog value) of the output power is converted into a digital value. The detection unit 33 can communicate with the communication processing unit 32, and transmits the converted detection value (digital value) of the output power to the communication processing unit 32.

The communication processing unit 32 relays communication between the processing device A1 and the solar PCS 31. The communication processing unit 32 receives a guidance command value from the processing device A1 and calculates an output target value of the solar PCS 31 based on the received guidance command value. The communication processing unit 32 calculates the output target value by calculating the above formula (3) and the above formula (4) in the same way as the communication processing unit 12 and each communication processing unit 22. However, the constraint conditions set in the communication processing unit 32 are different from those of the communication processing unit 12 and each communication processing unit 22. The communication processing unit 32 generates a control command including the calculated output target value and transmits this to the solar PCS 31. The communication processing unit 32 also relays communication between the detection unit 33 and the processing device A1. The communication processing unit 32 receives the detection value of the output power transmitted from the detection unit 33 and transmits this to the processing device A1.

The solar PCS 31 is connected to a solar cell 39, and converts the power (e.g., DC power) generated by the solar cell 39 into power (e.g., AC power) suitable for grid connection and outputs it. In FIG. 4, one solar cell 39 is connected to the solar PCS 31, but multiple solar cells 39 may be connected. The solar PCS 31 is connected to a third winding 913 of a transformer 91 by a power line 90. The solar PCS 31 outputs the power generated by the solar cell 39 to the transformer 91. The solar PCS 31 controls the output power of the control object (solar cell 39) by controlling the amount of power generated by the solar cell 39 based on a control command received from the communication processing unit 32. Specifically, the solar PCS 31 controls power so that the output power of the solar cell 39 becomes the output target value included in the control command. Note that the solar PCS 31 may not control the output power (power generation amount) of the solar cell 39. In this case, the solar PCS 31 can stop the output of power by an external contact.

Next, we will explain what happens when communication between devices in power system S2 is not performed normally. For cases 1 to 4 above, power system S2 is processed in the same way as power system S1.

<Case 5: Communication Abnormality Between the Communication Processing Unit 32 and the Detection Unit 33>
When a communication abnormality occurs between the communication processing unit 32 and the detection unit 33, the communication processing unit 32 cannot correctly receive the detection value of the output power of the solar PCS 31 from the detection unit 33. As a result, the communication processing unit 32 cannot transmit the detection value of the output power value to the processing device A1, so that the processing device A1 does not know the output power of the solar PCS 31, and the capacity of the transformer 91 may be exceeded (the winding capacity of the first winding 911 may be exceeded or the winding capacity of the third winding 913 may be exceeded) or the storage battery 19 may be overcharged during independent operation.

Therefore, when the processing device A1 cannot correctly receive the detection value of the output power of the solar PCS 31 from the communication processing unit 32, it stops the solar PCS 31 through an external contact (not shown). Note that the processing device A1 may stop the solar PCS 31 when it receives a PV communication abnormality notification transmitted from the communication processing unit 32, rather than when it cannot correctly receive the detection value of the output power. Furthermore, when the processing device A1 cannot correctly receive the detection value of the output power of the solar PCS 31 from the communication processing unit 32, or when it receives a PV communication abnormality notification transmitted from the communication processing unit 32, it turns on the PV communication abnormality flag and transmits a notification indicating that the PV communication abnormality flag is on (PV communication abnormality flag on notification) to each EV charge/discharge control device 20. Each EV charge/discharge control device 20 that receives the PV communication abnormality flag on notification notifies each EV stand 21 that a communication abnormality has occurred between the communication processing unit 32 and the detection unit 33.

In the power system S2, as in the power system S1, the EV charge/discharge control device 20 controls the charging and discharging of the electric vehicle 29 based on an optimization problem using an induced command value. Therefore, the power system S2 is capable of energy management, including the charging and discharging control of the electric vehicle 29, by the EV charge/discharge control device 20.

Furthermore, like the power system S1, the power system S2 suppresses unintended charging and discharging of the electric vehicle 29, and allows the user of the EV charge/discharge control device 20 (EV stand 21) to be informed of the occurrence of a communication abnormality. Furthermore, like the power system S1, the power system S2 can appropriately control the charging and discharging of the electric vehicle 29 by the EV charge/discharge control device 20 by changing the charge/discharge permission flag according to the control mode. Furthermore, like the power system S1, the power system S2 can suppress failures of the transformer 91 and eliminate excess winding capacity of the first winding 911.

In the second embodiment, the detection unit 33 transmits the detection value of the output power to the communication processing unit 32, and the communication processing unit 32 transmits the received detection value of the output power to the processing device A1 via the network hub H1. However, the following configuration may be used instead. That is, the detection unit 33 may be capable of communicating with the network hub H1, and may transmit the detection value of the output power to the processing device A1 via the network hub H1.

In the second embodiment, the configuration of the PV output control device 30 is not limited to the above example, and may be configured as follows, similar to the storage battery charge/discharge control device 10. That is, the solar PCS 31 detects the output power of the solar cell 39 and transmits it to the communication processing unit 32. The communication processing unit 32 may then receive the detected value of the output power from the solar PCS 31 and transmit the detected value of the output power received via the network hub H1 to the processing device A1. In this case, the PV output control device 30 may not include the detection unit 33.

The power system disclosed herein is not limited to the above-described embodiment. The specific configuration of each part of the power system disclosed herein can be freely designed in various ways.

S1, S2: Power system, A1: Processing device, B1: Power control device, C1: Detection device, D: Power system, 10: Battery charge/discharge control device, 11: Battery PCS, 12: Communication processing unit, 19: Battery, 20: EV charge/discharge control device, 21: EV stand, 22: Communication processing unit, 29: Electric vehicle, 30: PV output control device, 31: Solar PCS, 32: Communication processing unit, 33: Detection unit, 39: Solar cell, 81: Detection unit, 82: Communication processing unit, 91: Transformer, 911: First winding, 912: Second winding, 913: Third winding

Claims (4)

An electric power system that is connected to an electric power grid and performs power control of a connection point power, which is power at a connection point with the electric power grid,
a detection device for detecting the value of the node power;
A processing device that derives an induction command value for adjusting the value of the connection point power to a set adjustment target value;
a plurality of power control devices each electrically connected to the connection point and configured to control output power based on an optimization problem using the induction command value;
Equipped with
The plurality of power control devices include a first charge/discharge control device connected to a storage battery and a second charge/discharge control device to which an electric vehicle can be connected;
The first charge/discharge control device controls charging/discharging of the storage battery,
The second charge/discharge control device controls charging/discharging of the electric vehicle,
when a communication abnormality occurs in any of the communication between the detection device and the processing device, the communication between the processing device and the first charging/discharging control device, and the communication between the processing device and the second charging/discharging control device, the second charging/discharging control device notifies the occurrence of the communication abnormality while stopping charging/discharging of the electric vehicle;
The second charge/discharge control device includes an EV stand having an alarm device, and causes the alarm device of the EV stand to notify the occurrence of the communication abnormality.
1. A power system comprising: the processing device transmits flag information for specifying whether the electric vehicle is capable of being charged and whether the electric vehicle is capable of being discharged to the second charge/discharge control device,
the second charge/discharge control device receives the flag information and controls charging/discharging of the electric vehicle based on the induced command value and the received flag information;
The flag information is determined according to a control mode for the power control.
The power system of claim 1 . An electric power system that is connected to an electric power grid and performs power control of a connection point power, which is power at a connection point with the electric power grid,
a detection device for detecting the value of the node power;
A processing device that derives an induction command value for adjusting the value of the connection point power to a set adjustment target value;
a plurality of power control devices each electrically connected to the connection point and configured to control output power based on an optimization problem using the induction command value;
a three-winding transformer including a first winding, a second winding, and a third winding;
Equipped with
The plurality of power control devices include a first charge/discharge control device connected to a storage battery and a second charge/discharge control device to which an electric vehicle can be connected;
The first charge/discharge control device controls charging/discharging of the storage battery,
The second charge/discharge control device controls charging/discharging of the electric vehicle,
when a communication abnormality occurs in any of the communication between the detection device and the processing device, the communication between the processing device and the first charging/discharging control device, and the communication between the processing device and the second charging/discharging control device, the second charging/discharging control device notifies the occurrence of the communication abnormality while stopping charging/discharging of the electric vehicle;
the first winding is connected to the connection point;
the second winding is connected to the first charge/discharge control device;
the third winding is connected to the second charge/discharge control device,
the processing device receives output powers of the power control devices from the respective ones of the plurality of power control devices, and when a total value of the received output powers exceeds a winding capacity of the first winding, transmits a setting value for eliminating the excess as the induction command value to each of the plurality of power control devices;
1. A power system comprising: the set value is a value that stops charging/discharging of the storage battery when the total value exceeds the winding capacity in a state in which power is supplied from the connection point side to the three-winding transformer side, and is a value that stops charging/discharging of the electric vehicle when the total value exceeds the winding capacity in a state in which power is supplied from the three-winding transformer side to the connection point side.
The power system of claim 3 .

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