JP2020088938A - Operation control system, control device, and operation control method - Google Patents

Abstract

To provide an operation control system in which deterioration in the power generation efficiency is suppressed so that occurrence of a reverse power flow can be stopped within a short time period.SOLUTION: An operation control system 100 includes a plurality of PCSs 50-1 to 50-n that control power generated by PVs 60-1 to 60-n, and a control device 70 that controls the plurality of PCSs 50-1 to 50-n. The control device 70 includes a power conditioner determining unit 72 that, when receiving a load signal indicating a reverse power flow, determines a PCS 50 to stop the operation, among the plurality of PCSs 50-2 to 50-n, and a stop instruction output unit 73 that issues an operation stop instruction to the PCS 50 determined by the power conditioner determining unit 72. Each of the PCSs 50-1 to 50-n includes an operation stop unit 52 that stops the operation on the basis of the operation stop instruction from the control device 70, and an operation restoring unit 53 that restores the operation after elapse of a prescribed restoration time period from reception of the operation stop instruction.SELECTED DRAWING: Figure 1

Description

The present invention relates to an operation control system, a control device, and an operation control method.

In recent years, a solar power generation system that uses a solar panel to generate power has been used. When the generated power is not sold to an electric power company like a self-consumption type solar power generation system, it is necessary to prevent the power generated by the solar panel from flowing backward to the commercial power supply side. When a reverse tide occurs, it is necessary to stop the reverse tide within a predetermined time (for example, 2 sec) determined by the electric power company. Therefore, the maximum power point tracking control (MPPT: Maximum Power Point Tracking) is performed so that the power of the solar cell connected to the power conditioner is maximized in the range that does not flow backward.

Further, for example, as a technique for preventing reverse flow to the commercial power source side, a technique for setting a limit power for avoiding reverse flow and controlling the generated power of the solar cell by a power conditioner so as to be less than the limit power. Is disclosed (for example, see Patent Document 1).

JP2012-175858A

However, even when the limit power is set to avoid reverse power flow, for example, when an electric appliance with a large load power is stopped, the load power may suddenly fall below the power generated by the entire solar cell. is assumed. In that case, the generated power greatly exceeds the load power, and a reverse flow occurs on the commercial power source side. Since the power control by the power conditioner takes time, even if the power generated by the power conditioner is controlled by the technique of Patent Document 1 or the maximum power point tracking control after the backflow occurs, the electric power supplier sets a predetermined value. The reverse tide may not be resolved within the time. In that case, the entire power conditioner is shut off, and no power is generated until the operation of the power conditioner is restored.

Further, when the limit power is set low so that the reverse tide does not occur, the power generated by the solar cell becomes low and the power generation efficiency becomes poor.

The present invention has been made in view of the above problems, and an object thereof is to provide an operation control system capable of suppressing a decrease in power generation efficiency and stopping the occurrence of reverse tide in a short time.

The operation control system according to the first aspect of the present invention is an operation control system including a plurality of power conditioners that control generated power of a solar cell and a control device that controls the plurality of power conditioners. When the control device receives a load signal indicating reverse power flow, the control device determines a power conditioner for stopping operation among the plurality of power conditioners, and the power conditioner. A stop instruction output unit for issuing an operation stop instruction to the power conditioner determined by the determination unit, wherein the plurality of power conditioners stop operation based on the operation stop instruction from the control device. The operation control system includes: a stop unit; and an operation return unit that returns operation after a predetermined return time has elapsed after receiving the operation stop instruction.

The control device according to the second aspect of the present invention controls the generated power of the solar cell, stops the operation based on the operation stop instruction, and after a predetermined recovery time elapses after receiving the operation stop instruction, A control device for controlling a plurality of power conditioners for returning operation, wherein the control device, when receiving a load signal indicating a reverse tide, of the plurality of power conditioners, the power for stopping the operation. The control device includes a power conditioner determination unit that determines a conditioner, and a stop instruction output unit that issues an operation stop instruction to the power conditioner determined by the power conditioner determination unit.

The operation control method according to the third aspect of the present invention controls the generated power of the solar cell, stops the operation based on the operation stop instruction, and after a predetermined recovery time elapses after receiving the operation stop instruction. A method for controlling the operation of a control device for controlling a plurality of power conditioners for returning operation, wherein when a load signal indicating a reverse flow is received, the power for stopping operation among the plurality of power conditioners is selected. The operation control method determines a conditioner and issues an operation stop instruction to the determined power conditioner.

According to one aspect of the present invention, it is possible to suppress a decrease in power generation efficiency and stop the occurrence of reverse tide in a short time.

It is a figure which shows an example of the driving control system of embodiment of this invention. It is a figure which shows an example which a power conditioner determination part determines by rotating PCS which stops operation. It is a figure which shows the operation time of each PCS memorize|stored in the memory|storage part of an electric power monitoring system, the accumulated result of the electric power generation, and the operation frequency. It is a figure which shows an example of the relationship between load electric power and electric power generation. It is a figure which shows an example of the relationship between load electric power and electric power generation in each operation mode. It is a flow chart which shows an example of operation control processing which a control device performs. It is a flow chart which shows an example of PCS control processing which PCS performs.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a diagram showing an example of an operation control system 100 according to an embodiment of the present invention. The operation control system 100 is not particularly limited, but is installed in, for example, a factory. The operation control system 100 may be set in a store or a house. The operation control system 100 is connected to the commercial power source S via the commercial power line 11. The operation control system 100 is supplied with commercial power transformed by a transformer or the like.

As shown in FIG. 1, the operation control system 100 includes a current sensor 20, a converter 30, a power monitoring system 40, a plurality of power conditioners (hereinafter referred to as “PCS”) 50-1 to 50-n. , A plurality of Photovoltaics (hereinafter referred to as “PV”) 60-1 to 60-n, a control device 70, a BMU (Battery management system) 80, and a load group 90. The operation control system 100 may include other circuit elements not shown in FIG. Note that, when the plurality of PCSs 50-1 to 50-n are described separately, they are also referred to as “first PCS 50-1,” “second PCS 50-2,” “third PCS 50-3,”... “nth PCS 50-n.” .. Further, when it is not necessary to particularly distinguish and describe the plurality of PCSs 50-1 to 50-n, they will be referred to as “PCS 50” hereinafter. Similarly, when it is not necessary to particularly distinguish and describe a plurality of PVs 60-1 to 60-n, they will be referred to as "PV60" hereinafter. In addition, in FIG. 1, a solid line indicates a power line and a dotted line indicates a signal line.

The current sensor 20 is configured by an instrument current transformer (CT: Current Transformer) or the like. The current sensor 20 detects an alternating current on the commercial power source S side. A plurality of PCSs 50-1 to 50-n are connected to the output side of the current sensor 20 via the power monitoring system 40. Further, PVs 60-1 to 60-n are connected to the respective PCSs 50-1 to 50-n.

Each PV 60-1 to 60-n outputs the generated power generated by sunlight to each PCS 50-1 to 50-n. The PCS 50 has a bidirectional alternating current/direct current (AC/DC) converter, controls the generated power of the PV 60, converts the direct current output from the PV 60 into an alternating current, and supplies the alternating current to the power monitoring system 40. .. In the example of FIG. 1, one PV 60-1 to 60-n is connected to each PCS 50-1 to 50-n, but the present invention is not limited to this, and a plurality of PVs 60 are connected to one PCS 50. Good.

The current sensor 20 detects the alternating current supplied from the PCSs 50-1 to 50-n, that is, reverse current. The reverse tide is a difference obtained by subtracting the load group 90 from the generated electric power supplied from the PCSs 50-1 to 50-n. When the reverse current is detected, the current sensor 20 transmits a load signal obtained by converting the reverse current into a small current at a predetermined ratio to the converter 30. The converter 30 further converts the current of the load signal transmitted from the current sensor 20 into a smaller current and transmits it to the control device 70. As a result, the control device 70 can obtain the load signal indicating the backward flow transmitted from the current sensor 20 via the converter 30.

The power monitoring system 40 includes a monitoring control unit 41 and a storage unit 42. The power monitoring system 40 may include other circuit elements not shown in FIG. The monitoring control unit 41 sequentially measures the operating time, the generated power, and the number of times of operation of each PCS 50-1 to 50-n, and stores the cumulative result in the storage unit 42.

FIG. 3 is a diagram showing cumulative results of the operating time, the generated power, and the operating frequency of each of the PCSs 50-1 to 50-n stored in the storage unit 42 of the power monitoring system 40. As shown in FIG. 3, the storage unit 42 stores the cumulative results of the operating time (min), the generated power (kWh), and the operating frequency (times) for each of the PCSs 50-1 to 50-n. The PCS 50 includes an output control unit 51, an operation stopping unit 52, and an operation returning unit 53. The PCS 50 may include other circuit elements not shown in FIG.

The control device 70 includes an output control instruction unit 71, a power conditioner determination unit 72, a stop instruction output unit 73, an operating number control unit 74, a switching unit 75, and a storage unit 76. The control device 70 may include other circuit elements not shown in FIG.

When the output control instructing unit 71 receives the load signal indicating the reverse flow from the current sensor 20, the output power of the PCS 50 is equal to or less than the load power before the operation instruction to the PCS 50 is issued by the stop instruction outputting unit 73. The output control instruction of the PCS 50 is issued so that In the output control instruction, the AC output suppression range for each PCS 50-1 to 50-n is set. As the suppression range, for example, a suppression range of 100 to 50% is set. Further, when the load power is increasing, the output control instructing unit 71 issues an output control instruction of 100% output to each of the PCSs 50-1 to 50-n.

The output control unit 51 of the PCS 50, which receives the output control instruction from the output control instruction unit 71, controls the generated power of the PCS 50 so as to fall within the suppression range included in the output control instruction. For example, when the suppression range included in the output control instruction is 50%, the PCS 50 controls the generated power to be suppressed to 50% of the maximum generated power. Further, the output control unit 51 of the PCS 50, which receives the output control instruction of 100% output from the output control instruction unit 71, performs control to increase the generated power of the PCS 50 so that the output becomes 100%.

When the power conditioner determination unit 72 receives the load signal indicating the reverse flow from the current sensor 20, the power conditioner determination unit 72 determines the PCS 50 to stop the operation among the plurality of PCSs 50-2 to 50-n. For example, when determining the PCS 50 to stop the operation, the power conditioner determination unit 72 rotates and determines the PCS 50-2 to 50-n to stop the operation. For example, the power conditioner determination unit 72 determines in advance the order of the PCS 50 to stop the operation, and stores the information of the last stopped PCS 50 in the storage unit 76. Then, the power conditioner determination unit 72 determines the next PCS 50 after the last stopped PCS 50 stored in the storage unit 76 as the stopped PCS 50. Further, even if the operation of the operation control system 100 is restarted the next day, the power conditioner determination unit 72 determines the PCS 50 to stop the PCS 50 next to the last stopped PCS 50 stored in the storage unit 76. can do. This makes it possible to decentralize the operating rates of the PCSs 50-2 to 50-n, reduce the load, and extend the life of the PCSs 50.

FIG. 2 is a diagram illustrating an example in which the power conditioner determination unit 72 rotates and determines the PCSs 50-2 to 50-n whose operation is stopped. As shown in FIG. 2, the power conditioner determination unit 72 sequentially determines the PCSs 50-2 to 50-n to stop the operation. For example, when the load signal indicating the reverse tide is received at time t1, the power conditioner determination unit 72 determines the second PCS 50-2 as the PCS 50 that stops the operation among the plurality of PCSs 50-2 to 50-n. To do. Then, when the load signal indicating the reverse tide is received at time t2, the power conditioner determination unit 72 determines the third PCS 50-3 next to the second PCS 50-2 as the PCS 50 that stops the operation. The power conditioner determination unit 72 repeatedly executes the same processing.

Further, the power conditioner determination unit 72 may preferentially determine the PCS 50 having the largest accumulated operating time among the plurality of PCSs 50-2 to 50-n. For example, the PCS 50 having the largest operating time “8,600 min” of the cumulative operating time information stored in the storage unit 42 of the power monitoring system 40 illustrated in FIG. 3 is the third PCS 50-3. The power conditioner determination unit 72 acquires information on the cumulative operating time stored in the storage unit 42 of the power monitoring system 40, and has the largest cumulative operating time among the PCSs 50-2 to 50-n. The third PCS 50-3 is determined as the PCS 50 that stops the operation. This makes it possible to disperse the operating time required for each of the PCSs 50-2 to 50-n, reduce the load, and extend the life of the PCS 50.

Further, the power conditioner determination unit 72 may preferentially determine the PCS 50 having a large cumulative amount of generated electric power among the plurality of PCSs 50-2 to 50-n. For example, the PCS 50 having the largest amount of generated power “4,176 kWh” among the accumulated information of the amount of generated power stored in the storage unit 42 of the power monitoring system 40 illustrated in FIG. 3 is the third PCS 50-3. The power conditioner determination unit 72 acquires information on the cumulative amount of generated power stored in the storage unit 42 of the power monitoring system 40, and the cumulative amount of generated power among the PCSs 50-2 to 50-n is calculated. The largest third PCS 50-3 is determined as the PCS 50 to stop the operation. As a result, it is possible to disperse the amount of power generated by each of the PCSs 50-2 to 50-n, reduce the load, and extend the life of the PCS 50.

In addition, the power conditioner determination unit 72 may preferentially determine the PCS 50 having a large number of times of operation among the plurality of PCSs 50-2 to 50-n. For example, the PCS 50 having the largest number of times of operation “2,032” of the accumulated information on the number of times of operation stored in the storage unit 42 of the power monitoring system 40 illustrated in FIG. 3 is the second PCS 50-2. The power conditioner determination unit 72 acquires the information on the cumulative number of times of operation stored in the storage unit 42 of the power monitoring system 40, and has the largest cumulative number of times of operations among the PCSs 50-2 to 50-n. The second PCS 50-2 is determined as the PCS 50 that stops the operation. This makes it possible to disperse the number of times of operation for each PCS 50-2 to 50-n, reduce the load, and extend the life of the PCS 50.

Further, the power conditioner determination unit 72 may preferentially determine the PCS 50 that generates less power at the time of receiving the load signal indicating the reverse tide among the plurality of PCSs 50-2 to 50-n. In this case, the power conditioner determination unit 72 acquires information on the generated power at the time when the load signal is received from the power monitoring system 40. For example, when the PCS 50 with the smallest generated power at the time of receiving the load signal is the second PCS 50-2, the power conditioner determination unit 72 selects the second PCS 50-2 among the PCSs 50-2 to 50-n. It is determined as the PCS 50 to stop the operation. As a result, it is possible to minimize the amount of power generation generated when the operation of the PCS 50 is stopped, and prevent a decrease in power generation efficiency.

In the above-described embodiment, the first PCS 50-1 is not included in the PCS 50 that stops the operation determined by the power conditioner determination unit 72, but is not limited thereto. For example, when power is not stored in the BMU 80, the power conditioner determination unit 72 sets, as the PCS 50 that stops the operation, the PCS 50 that stops the operation among the plurality of PCSs 50-1 to 50-n including the first PCS 50-1. You may decide.

The stop instruction output unit 73 issues an operation stop instruction to the PCS 50 determined by the power conditioner determination unit 72. The operation stop unit 52 of the PCS 50 stops the operation based on the operation stop instruction from the control device 70. The operation stop by the operation stop unit 52 is possible within 1 to 1.8 seconds after the occurrence of the reverse tide, and the predetermined time set by the electric power supplier is, for example, 2 seconds. The backflow can be stopped in time.

The operation recovery unit 53 recovers the operation after a predetermined recovery time elapses after receiving the operation stop instruction from the control device 70. The predetermined return time is a time set by the electric power company. The predetermined recovery time is, for example, 300 seconds. The predetermined return time can be arbitrarily changed to correspond to the time set by the electric power company. For example, the operation recovery unit 53 activates the operation recovery timer based on the operation stop instruction from the control device 70, and recovers the stopped operation when the operation recovery timer expires after the elapse of a predetermined recovery time.

Next, the relationship between the load power and the generated power will be described. FIG. 4 is a diagram showing an example of the relationship between the load power and the generated power. In addition, in FIG. 4, the wavy line indicates the load power, and each block indicates the generated power for each of the PCSs 50-1 to 50-n. In FIG. 4, a case where a reverse tide occurs at time t11 will be described.

As shown in FIG. 4A, when the reverse tide R occurs at time t11 and the load signal indicating the reverse tide is received from the current sensor 20, the output control instructing unit 71 of the control device 70 causes the output control instruction unit 71 of the PCS 50 to operate. An output control instruction of the PCS 50 is issued so that the output power becomes equal to or lower than the load power. For example, when the suppression range included in the output control instruction is 90%, the output control unit 51 of the PCS 50 suppresses the generated power to 90% of the maximum generated power as illustrated in FIG. 4B. Control. This eliminates the back tide.

On the other hand, as shown in FIG. 4(3), when the load power is significantly reduced, the decrease in the generated power under the control of the output control unit 51 of the PCS 50 cannot be made in time for the decrease in the load power, so that the electricity business It may not be possible to stop the reverse tide within a predetermined time set by the person.

In this case, the power conditioner determination unit 72 determines the PCS 50 to stop the operation among the plurality of PCSs 50-2 to 50-n. The stop instruction output unit 73 issues an operation stop instruction to the PCS 50 determined by the power conditioner determination unit 72. The operation stop unit 52 of the PCS 50, which has received the operation stop instruction from the control device 70, stops the operation.

Thereby, even when the load power is greatly reduced, the operation of the determined PCS 50 among the plurality of PCSs 50-2 to 50-n can be immediately stopped as shown in FIG. 4(4). .. Therefore, the occurrence of reverse tide can be stopped in a short time. Further, since only the PCS 50 determined by the power conditioner determination unit 72 can be stopped, it is possible to suppress the decrease in power generation efficiency.

The operating number control unit 74 determines the number of PCSs 50 to be operated according to a preset operation mode. The operation mode can be set for each preset schedule. The information on the operation mode is stored in the storage unit 76. For example, the operating mode includes a plurality of operating modes including a weekday operating mode, a half-day operating mode, and a holiday operating mode. Further, switching to each operation mode can be arbitrarily changed based on the operation of the operator.

FIG. 5 is a diagram showing an example of the relationship between the load power and the generated power in each operation mode. In addition, in FIG. 5, the wavy line indicates the load power, and each block indicates the generated power for each of the PCSs 50-1 to 50-n.

As shown in FIG. 5(1), when the weekday operation mode is set based on the operation of the operator, the operating unit number control unit 74, the operating unit number control unit 74, from time t21 to time t22, The number of all PCSPCSs 50-1 to 50-n is determined as the number of operating PCSs 50.

As shown in FIG. 5(2), when the half-day operation mode is set based on the operation of the operator, the operating unit number control unit 74 controls all the PCSPCSs 50-1 to 50 from time t21 to time t23. The number of -n is determined as the number of operating PCSs 50. Further, when the half-day operation mode is set, the operating unit number control unit 74 operates the PCS 50 that operates the arbitrarily set number of PCSs 50 among the PCSPCSs 50-1 to 50-n from time t23 to time t22. Determine as the number of units. In the example of FIG. 5(2), the number of PCSs 50 operated by two PCSs 50 is determined as an arbitrarily set number.

As shown in FIG. 5C, when the holiday operation mode is set based on the operation of the operator, the operating unit number control unit 74 sets any of PCSPCS 50-1 to 50-n from t21 to t22. It is determined as the number of PCSs 50 that operate the number of PCSs 50 set to. In the example of FIG. 5(3), the number of PCSs 50 operated by two PCSs 50 is determined as the arbitrarily set number.

As a result, wasteful power generation can be suppressed, the load on each PCS 50-1 to 50-n can be reduced, and the life of the PCS 50 can be extended. Further, by generating power corresponding to the minimum load power required, it is possible to prevent the occurrence of reverse tide.

The BMU 80 is capable of storing excess power supplied from the PCS 50 and discharging it when power is insufficient. The BMU 80 corresponds to the power storage unit of the present invention. The BMU 80 includes a power storage control unit 81 and a battery 82. The BMU 80 may include other circuit elements not shown in FIG.

When the switching unit 75 of the control device 70 receives the load signal indicating the reverse flow output from the current sensor 20, before the stop instruction output unit 73 issues an operation stop instruction to the PCS 50, the plurality of PCS 50-1 to PCS 50-1. The output of the first PCS 50-1 of 50-n is switched to the BMU 80. When power is supplied from the first PCS 50-1, the power storage control unit 81 of the BMU 80 stores the supplied power in the battery 82. Thereby, the BMU 80 can store the surplus power supplied from the first PCS 50-1. The first PCS 50-1 corresponds to the specific power conditioner of the present invention.

In addition, the switching unit 75 of the control device 70 causes the power stored in the battery 82 of the BMU 80 to pass the power stored in the battery 82 of the BMU 80 to the PCS 50 and the PV 60 via the power monitoring system 40 during a time period such as nighttime or bad weather when the PV 60 cannot generate power. , The control device 70 and the like. As a result, standby power of each device can be supplemented by self-generated power, and power generation efficiency can be improved.

The storage unit 42 of the power monitoring system 40 is realized by a memory. The monitoring control unit 41 of the power monitoring system 40 is realized by a processor system. The processor system includes a processor element and provides the function of the monitoring control unit 41 by executing a given program.

The output control unit 51, the operation stopping unit 52, and the operation returning unit 53 of the PCS 50 are realized by the processor system. The processor system includes a processor element and a memory, and provides the functions of the output control unit 51, the operation stopping unit 52, and the operation returning unit 53 by executing a given program.

The storage unit 76 of the control device 70 is realized by a memory. Further, the output control instruction unit 71, the power conditioner determination unit 72, the stop instruction output unit 73, the operating number control unit 74, and the switching unit 75 of the control device 70 are realized by a processor system. The processor system includes a processor element and provides the functions of an output control instruction unit 71, a power conditioner determination unit 72, a stop instruction output unit 73, an operating number control unit 74, and a switching unit 75 by executing a given program. To do.

Next, an example of the flow of processing of the operation control method of the embodiment will be described with reference to FIGS. 6 to 7. FIG. 6 is a flowchart showing an example of the operation control process executed by the control device 70.

First, the output control instructing unit 71 determines whether or not the load signal transmitted from the current sensor 20 is received (step S11). If the load signal has not been received (NO in step S11), the process waits until the load signal is received. When the load signal is received (YES in step S11), the output control instructing unit 71 determines whether or not the load signal indicating the reverse flow is received again within a predetermined time after receiving the load signal indicating the reverse flow. Is determined (step S12). In the process of step S12, the reverse flow is not resolved even though the output suppression instruction of the output X% is issued to each of the PCSs 50-1 to 50-n in step S14 described later, and the load signal indicating the reverse flow is received again. It is determined whether or not.

When the load signal indicating the reverse tide is not received again within a predetermined time after receiving the load signal indicating the reverse tide (NO in step S12), that is, when the load signal indicating the reverse tide is received for the first time. The output control instruction unit 71 determines whether the information included in the load power is load power increase or decrease (step S13). When the load power has decreased (step S13: decrease), the output control instructing unit 71 issues an output suppression instruction of the output X% to each of the PCSs 50-1 to 50-n (step S14). When the process of step S14 ends, the process returns to step S11.

When the load power increases (step S13: increase), the output control instruction unit 71 issues an output control instruction of 100% output to each of the PCSs 50-1 to 50-n (step S15). When the process of step S15 ends, the process returns to step S11.

When the load signal indicating the reverse tide is received again within a predetermined time after receiving the load signal indicating the reverse tide (YES in step S12), the switching unit 75 outputs the AC output of the first PCS 50-1 to the BMU 80. It is determined whether the switching has been completed (step S16). The determination of YES in step S12 is made when the reverse flow continues despite the output X% suppression command being issued to each of the PCSs 50-1 to 50-n in step S14.

When the AC output of the first PCS 50-1 is not switched to the BMU 80 (NO in step S16), the switching unit 75 determines whether the battery 82 of the BMU 80 is full (step S17). If the battery 82 of the BMU 80 is full (YES in step S17), the process proceeds to step S19. When the battery 82 of the BMU 80 is not full (NO in step S17), the switching unit 75 switches the AC output of the first PCS 50-1 to the BMU 80 (step S18).

When the AC output of the first PCS 50-1 is switched to the BMU 80, the power storage control unit 81 of the BMU 80 stores the battery 82 with the AC output of the first PCS 50-1. As a result, it is possible to suppress the reverse tide and to supplement the standby power of the power monitoring system 40, the PCS 50, the PV 60, the control device 70, the BMU 80, etc. during a time period when the PV 60 cannot generate power by storing the surplus power in the battery 82. be able to. Thereby, the power generation efficiency can be improved. When this process ends, the process returns to step S11.

When the AC output of the first PCS 50-1 has already been switched to the BMU 80 (YES in step S16), the power conditioner determination unit 72 determines the PCS 50 to be stopped by rotation (step S19). The stop instruction output unit 73 issues an operation stop instruction to the PCS 50 determined in step S19 (step S20). In step S20, the operation stop unit 52 of the PCS 50 that has received the operation stop instruction from the control device 70 stops the operation. When the process of step S20 ends, the process returns to step S11. The processes of steps S19 and S20 are executed a plurality of times until the backflow is resolved. That is, if the backflow does not disappear even if the operation of one PCS 50 is stopped, the power conditioner determination unit 72 determines the next PCS 50 as the PCS 50 to be stopped. Then, the stop instruction output unit 73 issues an operation stop instruction to the PCS 50 determined by the power conditioner determination unit 72. The next PCS 50 that receives the operation stop instruction stops the operation. As a result, even when the load power suddenly decreases, it is possible to stop the occurrence of reverse tide in a short time.

FIG. 7 is a flowchart showing an example of the PCS control processing executed by the PCSs 50-1 to 50-n.

First, the operation stop unit 52 determines whether or not an operation stop instruction has been received from the control device 70 (step S51). When the operation stop instruction is received (YES in step S51), the operation stop unit 52 stops the operation based on the operation stop instruction from the control device 70 (step S52). Then, the operation recovery unit 53 activates the operation recovery timer (step S53). The operation recovery unit 53 determines whether the operation recovery timer started in step S53 has expired (step S54). If the operation recovery timer has not expired (NO in step S54), the process waits until the operation recovery timer expires. When the operation recovery timer has expired (YES in step S54), the operation stopped in step S52 is recovered (step S55). When this process ends, the process returns to step S51.

When the operation stop instruction has not been received (NO in step S51), the output control unit 51 determines whether the output control instruction has been received (step S56). If the output control instruction has not been received (NO in step S56), the process returns to step S11. When the output control instruction is received (YES in step S56), the output control unit 51 performs output control (step S57). In the process of step S57, the output control unit 51 performs control for suppressing the power generated by the PCS 50 so that the power is within the suppression range included in the output control instruction. For example, the output control unit 51 performs control for suppressing the power generated by the PCS 50 so that the power is within the suppression range included in the output control instruction. When receiving the output control instruction of 100% output, the output control unit 51 performs control to increase the generated power of the PCS 50 so that the output becomes 100%. When the process of step S57 ends, the process returns to step S51.

The present invention is not limited to the above-described embodiments as they are, and can be embodied by modifying the constituent elements without departing from the scope of the invention at the implementation stage. Further, various inventions can be formed by appropriately combining a plurality of constituent elements disclosed in the above-described embodiments. For example, all the constituent elements shown in the embodiments may be combined appropriately. Furthermore, the constituent elements of different embodiments may be combined appropriately. Various modifications and applications are possible without departing from the spirit of the invention.

11: Commercial power line 20: Current sensor 30: Converter 40: Power monitoring system 41: Monitoring control unit 42: Storage units 50-1 to 50-n: PCS
51: Output control unit 52: Operation stop unit 53: Operation recovery unit 60-1 to 60-n: PV
70: Control device 71: Output control instruction part 72: Power conditioner determination part 73: Stop instruction output part 74: Operating number control part 75: Switching part 76: Storage part 80: BMU
81: Power storage control unit 82: Battery 90: Load group 100: Operation control system R: Reverse tide S: Commercial power supply

Claims (12)

A plurality of power conditioners that control the generated power of the solar cells, and a control device that includes a control device that controls the plurality of power conditioners,
The control device is
When receiving a load signal indicating a reverse tide, among the plurality of power conditioners, a power conditioner determination unit that determines a power conditioner to stop operation,
A stop instruction output unit for issuing an operation stop instruction to the power conditioner determined by the power conditioner determination unit,
The plurality of inverters are
An operation stop unit that stops operation based on the operation stop instruction from the control device,
An operation control system comprising: an operation recovery unit that recovers operation after a predetermined recovery time has elapsed after receiving the operation stop instruction. The operation control system according to claim 1, wherein the power conditioner determination unit rotates and determines a power conditioner that stops operation. The operation control system according to claim 2, wherein the power conditioner determination unit prioritizes and determines a power conditioner having a long cumulative operation time among the plurality of power conditioners. The operation control system according to claim 2, wherein the power conditioner determination unit preferentially determines a power conditioner having a large cumulative amount of generated power among the plurality of power conditioners. The operation control system according to claim 2, wherein the power conditioner determination unit preferentially determines a power conditioner that has been operated a large number of times among the plurality of power conditioners. The power conditioner determination unit preferentially determines, among the plurality of power conditioners, a power conditioner that generates less power at the time of receiving a load signal indicating the reverse flow. The operation control system described in. The operation control according to any one of claims 1 to 6, wherein the control device further includes an operating unit number control unit that determines the number of power conditioners to be operated in accordance with a preset operation mode. system. The operation control system according to claim 7, wherein the operation mode is set for each preset schedule. The operation control system further includes a power storage unit,
The control device is
Before the stop instruction output unit issues an operation stop instruction to the power conditioner, a switching unit that switches the output of a specific power conditioner of the plurality of power conditioners to the power storage unit is further provided. The operation control system according to any one of claims 1 to 8. The control device further includes
When a load signal indicating the reverse tide is received, the output power of the power conditioner should be equal to or less than the load power before the stop instruction output unit issues an operation stop instruction to the power conditioner. The operation control system according to any one of claims 1 to 9, further comprising an output control instructing unit that issues an output control instruction of the power conditioner. A control device that controls a plurality of power conditioners that control the generated power of the solar cell, stop the operation based on the operation stop instruction, and return the operation after a predetermined recovery time has elapsed after receiving the operation stop instruction. And
The control device, when receiving a load signal indicating reverse flow, of the plurality of power conditioners, a power conditioner determination unit that determines a power conditioner to stop operation,
A control device, comprising: a stop instruction output unit that issues an operation stop instruction to the power conditioner determined by the power conditioner determination unit. A control device that controls a plurality of power conditioners that control the generated power of the solar cell, stop the operation based on the operation stop instruction, and return the operation after a predetermined recovery time has elapsed after receiving the operation stop instruction. The operation control method of
When receiving a load signal indicating a reverse tide, of the plurality of power conditioners, determine the power conditioner to stop the operation,
An operation control method comprising issuing an operation stop instruction to the determined power conditioner.

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