Power supply system and power controller

Abstract

To provide a power supply system and a power controller that can prevent as much as possible a deviation from an output control value caused by the resolution of control of a power generating unit.SOLUTION: The present disclosure is a power supply system for a consumer that can transmit surplus power to a power system, and comprises a power generating unit and a controller that controls the power generating unit. The controller controls the power generating unit so that the magnitude of reverse power flow transmitted from the consumer to the power system falls below an output control value notified from a host device.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to a power supply system and a power control device. [Background technology]

[0002] When electricity consumers equipped with photovoltaic power generation facilities or other power generation facilities generate more electricity than they consume, they may transmit the surplus electricity to the power grid through reverse power flow. However, power grids maintain the stability of system frequency and voltage by balancing supply and demand. For this reason, when the supply of electricity in a power grid exceeds demand, output control may be implemented to limit the output of the power generation facilities that supply electricity to the power grid (see, for example, Patent Document 1).

[0003] Output control is usually performed using an output control value that represents the limit on power generation as a percentage. Therefore, when an output control method is applied that applies an output control value expressed as a percentage within the difference obtained by subtracting the minimum amount of power that the consumer consumes (minimum load amount) from the maximum power that the consumer can transmit to the power grid (maximum received power), if the difference is small, there is a possibility that the output control value will deviate due to a slight error caused by the control resolution of the power generation equipment. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2018-152997 Summary of the Invention [Problem to be solved by the invention]

[0005] The present application has been made in view of the above circumstances, and discloses a power supply system and a power control device that can suppress deviation from an output control value caused by the resolution of control of a power generation facility as much as possible. [Means for solving the problem]

[0006] In order to solve the above problem, in the present invention, the power generation equipment is controlled so that the magnitude of the reverse power flow falls below the output control value.

[0007] In detail, the present disclosure relates to a power supply system for a consumer that can transmit surplus power to a power grid, the power supply system comprising a power generation facility and a control device that controls the power generation facility, and the control device controls the power generation facility so that the magnitude of the reverse power flow transmitted from the consumer to the power grid is below an output control value notified by a higher-level device.

[0008] In such a power supply system, the power generation equipment is controlled so that the output is below the output control value notified by the higher-level device, thereby minimizing the possibility of reverse power flow exceeding the upper limit of the error allowed in output control due to the resolution of the control.

[0009] The control device may be a power supply system that controls the power generation equipment of the consumer so that the ratio of the reverse power flow to the upper limit power that can be transmitted to the power grid is below the output control value. This makes it possible to minimize the possibility of reverse power flow exceeding the upper limit of error allowed in output control while ensuring that the ratio of the reverse power flow to the upper limit power is a value corresponding to the output control value.

[0010] The upper limit of power is the minimum load for self-consumption from the maximum power received in the customer's contract. The power supply system may be a value obtained by subtracting the maximum received power from the power grid. Here, the maximum received power is the maximum power that the power consumer can transmit to the power grid. The minimum load is the minimum amount of power that the power consumer consumes. This allows the magnitude of the reverse power flow to be adjusted based on a clear value.

[0011] The control device may also be a power supply system that includes an output control unit that controls the power generation equipment so that the magnitude of the reverse power flow transmitted from the consumer to the power grid conforms to an output control value, and an adjustment unit that adjusts the output control unit so that the magnitude of the reverse power flow is below the output control value, and the adjustment unit adjusts the output control unit so that the magnitude of the reverse power flow is below the output control value by inputting a corrected value of the output control value to the output control unit. In this way, the corrected value of the output control value is input to the output control unit, making it possible to control the power generation equipment so that the magnitude of the reverse power flow transmitted from the consumer to the power grid conforms to the corrected value of the output control value.

[0012] The control device may also have an output control unit that controls the power generation equipment so that the difference between the amount of power generated by the power generation equipment and the power consumption value of the load consumption conforms to an output control value, and an adjustment unit that adjusts the output control unit so that the difference between the amount of power generated and the load consumption is below the output control value, and the output control unit is adjusted so that the difference between the amount of power generated and the load consumption is below the output control value by inputting the calculation result of the adjustment unit to the output control unit.In this way, since the calculation result of the adjustment unit is input to the output control unit, it is possible to control the power generation equipment so that the magnitude of the reverse flow transmitted from the consumer to the power grid is below the output control value.

[0013] Furthermore, the adjustment unit may be a power supply system that changes the adjustment amount when adjusting the output control unit in accordance with the ratio of the upper limit power that can be transmitted to the power grid of the consumer to the power generation capacity of the power generation facility. If the magnitude of the adjustment amount is increased or decreased in this manner, it becomes possible to control the power generation facility using a value that corresponds to the degree of impact that the control resolution of the power generation facility has on the reverse power flow.

[0014] Furthermore, the control device may be a power supply system that controls the power generation equipment so that the magnitude of the reverse power flow is less than the output control value by offsetting the output control value, multiplying the output control value by a proportional gain lower than 1, specifying the output control value in stages according to the output control value, applying the output control value to a mathematical formula, or using a value obtained by a combination of these to control the power generation equipment. This makes it possible to determine a control value based on the output control value for reducing the possibility of reverse power flow exceeding the upper limit of error allowed in output control.

[0015] The present disclosure may also be a power control device for a consumer that can transmit surplus power to a power grid, the power control device controlling a power generation facility so that the magnitude of the reverse power flow transmitted from the consumer to the power grid is below an output control value notified from a higher-level device. With such a power control device, it is possible to minimize the possibility of reverse power flow exceeding the upper limit of the error allowable in output control, which is caused by the control resolution. [Effects of the Invention]

[0016] The above-described power supply system can minimize deviation from the output control value due to the resolution of the power generation facility control. [Brief explanation of the drawings]

[0017] [Figure 1] FIG. 1 is a schematic configuration diagram of a power supply system according to an embodiment. [Figure 2] FIG. 2 is a diagram illustrating an example of the output control rules. [Figure 3] FIG. 3 is a diagram illustrating a schematic example of the state of power during output control. [Figure 4] FIG. 4 is a diagram illustrating a schematic example of an error in the control of generated power. [Figure 5] Figure 5 is a graph comparing the reverse power flow before and after adjustment. [Figure 6] FIG. 6 is a schematic diagram of a power supply system according to this modification. DETAILED DESCRIPTION OF THE INVENTION

[0018] <Application example> Hereinafter, application examples of the present disclosure will be described with reference to the drawings. The present disclosure is applied to a power supply system 1 shown in FIG.

[0019] The power supply system 1 is capable of converting power generated by a solar power generation facility or various other power generation facilities, and transmitting (selling) surplus power exceeding self-consumption to the power grid 2. When transmitting surplus power to the power grid 2, it is required to follow output control rules such as those shown in FIG. 2. When following these rules, for a consumer whose minimum load is relatively large compared to the power generation capacity of the power generation facility, there is a possibility that the output may deviate from the allowable error range during output control, as shown in FIG. 4(B), due to the influence of the control resolution of the power generation facility.

[0020] Therefore, in the power supply system 1, the output control controller 6B is adjusted so that the magnitude of the power of the reverse power flow is less than the output control command value, as shown in Fig. 5. This makes it possible to minimize the possibility of reverse power flow exceeding the upper limit of the error allowable in output control due to the control resolution.

[0021] <Embodiment> In the following, embodiments of the present invention will be described in more detail.

[0022] <Power supply system configuration> FIG. 1 is a schematic diagram of a power supply system 1 according to an embodiment. The power supply system 1 is a system operated by a consumer connected to a power grid 2, and is installed in a building or the like where various electrical loads 3 are installed. The power supply system 1 converts power generated by a solar power generation facility or various other power generation facilities and supplies the converted power to the loads 3 and the power grid 2. Therefore, the consumer operating the power supply system 1 can self-consumer the power of the loads 3 by supplying it from his / her own power generation facility. In addition, the consumer operating the power supply system 1 has concluded a contract with a business operator with which he / she trades electricity, which specifies various requirements such as the maximum received power (an example of the "upper limit power" in this application) and the minimum load. Therefore, the consumer operating the power supply system 1 can transmit (sell) surplus power generated by his / her own power generation facility that exceeds his / her self-consumption to the power grid 2.

[0023] The minimum load is the minimum value of power consumed by a consumer, for example, the minimum power consumption of the entire load 3. The maximum received power is the maximum value of reverse flow power that a consumer can transmit to the power grid 2, for example, a contractual value obtained by subtracting the minimum load from the maximum power generation power of the power generation equipment of the power supply system 1.

[0024] The following describes a schematic configuration of the power supply system 1. The power supply system 1 includes a PCS 4, an output control unit 6, and a power measurement unit .

[0025] The PCS 4 is a power conditioning system (PCS) connected to the electric circuit connecting the power grid 2 and the load 3. The built-in switching elements and other components operate appropriately. The power generated by the power generation equipment is supplied to the power grid 2 and the load 3 at a specified frequency and voltage.

[0026] The power measurement unit 7 is a device that measures the power received (received power or transmitted power) of the consumer operating the power supply system 1. The power measurement unit 7 measures the power received by the consumer using an ammeter installed near the power receiving point, which is the connection point between the drop line from the power system 2 to the premises and the distribution board on the premises. The PCS 4 and the load 3 are connected to the bus bar in the distribution board. Therefore, the power measurement unit 7 calculates the self-consumption power consumed by the load 3 from the power generated by the power generation equipment connected to the PCS 4. Only the difference after subtracting the power consumption is detected.

[0027] The output control unit 6 is a control device that controls the PCS 4 to control the power generated by the power generation equipment connected to the PCS 4. The output control unit 6 is an electronic control device that includes a CPU, memory, an input / output interface, etc., and the CPU executes a computer program loaded into the memory to realize various functional units such as an output control value calculation unit 6A, an output control controller 6B, and a set value storage unit 6C.

[0028] The output control value calculation unit 6A (an example of an "adjustment unit" in the present application) calculates an output control value (hereinafter, an "output control correction value") to be used when actually performing output control in the power supply system 1, based on an output control value (hereinafter, an "output control command value") notified from the power server 5 (an example of an "upper device" in the present application). The output control value calculation unit 6A receives the output control command value via a communication line such as the Internet from the power server 5 managed by the power utility that operates the power system 2. The output control command value that the output control value calculation unit 6A receives is notified from the power server 5 in the form of a schedule that defines an upper limit of output for each time period. This schedule is formulated by the utility that operates the power system 2 based on various information, such as power demand forecasts, the operating status of each power plant, and weather forecasts such as solar radiation.

[0029] The output control controller 6B (an example of the "output control unit" referred to in this application) compares the received power detected by the power measurement unit 7 with the output control correction value calculated by the output control value calculation unit 6A, and causes the PCS 4 to adjust the amount of power generated by the power generation equipment so that the ratio of the magnitude of the reverse power flow transmitted to the power grid 2 to the maximum received power matches the output control correction value.

[0030] The setting value storage unit 6C is a storage medium that stores various setting values, and for example, notifies the output control value calculation unit 6A of a correction value for calculating an output control correction value from an output control command value, and notifies various other values ​​to appropriate functional units.

[0031] <Output control rules> Next, an example of an output control rule applied to a consumer operating the power supply system 1 will be described. FIG. 2 is a diagram schematically illustrating an example of an output control rule. As an example of an output control rule applied to a consumer operating the power supply system 1, as shown in FIG. 2, there is an output control rule that applies an output control percentage only to the surplus power portion obtained by subtracting the power consumed by the consumer from the generated power. When this rule is applied, it becomes possible to sell power without suppressing the power consumed by the consumer, so that the power generated by the power generation facility can be used effectively and it is possible to suppress power selling losses. When such an output control rule is applied, the power supply system 1 operates as follows.

[0032] FIG. 3 is a diagram illustrating a schematic example of the state of power during output control. In FIG. 3, "D1" indicates the actual power generation amount of the power generation equipment of the power supply system 1, "D2" indicates the minimum load amount for self-consumption, "D3" indicates the magnitude of the actual reverse power flow (surplus power) transmitted to the power grid 2, "D4" indicates the magnitude of the maximum received power, and "D5" indicates the maximum power generation amount of the power generation equipment of the power supply system 1. Therefore, for example, if the power generation equipment of the power supply system 1 is a solar power generation equipment, "D1" changes from moment to moment depending on the amount of solar radiation, etc. "D2" is a fixed value agreed upon by the consumer operating the power supply system 1 and the utility company through a contract. "D3" is a reverse power flow, so it changes from moment to moment depending on the power generation amount of the power generation equipment. "D4" is a fixed value agreed upon by the consumer operating the power supply system 1 and the utility company through a contract.

[0033] The consumers who operate the power supply system 1 are classified into two types: consumers whose minimum load amount is relatively small compared to the power generation capacity of the power generation facility as shown in FIG. 3(A), and consumers whose minimum load amount is relatively small compared to the power generation capacity of the power generation facility as shown in FIG. 3(B). There may be consumers whose minimum load is relatively large compared to the power generation capacity of the facility. For example, in the case of a consumer whose power generation capacity is large compared to the power consumption of the power grid 2, the minimum load will be relatively small compared to the power generation capacity of the power generation facility. Also, for example, in the case of a consumer whose power generation capacity is small compared to the power consumption of the power grid 2, the minimum load will be relatively large compared to the power generation capacity of the power generation facility. When the output control rule shown in FIG. 2 is applied, output control is performed by percentage within the range of the maximum received power indicated by "D4" in FIG. 3. Therefore, in the case of a consumer whose minimum load is relatively large compared to the power generation capacity of the power generation facility, the amount of power generation power that should be increased or decreased according to output control is relatively small compared to the maximum power generation power (D5) of the power generation facility of the power supply system 1, as can be seen by comparing "D4" in FIG. 3(B) with "D4" in FIG. 3(A). 3(A) and 3(B), for example, even if the output control value is the same, 40%, the amount of the output control value of 40% in the maximum power generation power of the power generation facility is significantly different. Therefore, in the case of a consumer whose minimum load amount is relatively large compared to the power generation capacity of the power generation facility, unless the control of the power generation power is performed precisely with high resolution, there is a possibility that the allowable error range will be exceeded during output control, compared to the case of a consumer whose minimum load amount is relatively small compared to the power generation capacity of the power generation facility.

[0034] Figure 4 is a diagram showing a schematic example of an error in the control of power generation. Figure 4(A) shows the case of a consumer whose power generation amount to be increased or decreased according to output control is relatively large compared to the maximum power generation amount (D5) of the power generation equipment of the power supply system 1 (i.e., the case of the consumer shown in Figure 3(A)). On the other hand, Figure 4(B) shows the case of a consumer whose power generation amount to be increased or decreased according to output control is relatively small compared to the maximum power generation amount (D5) of the power generation equipment of the power supply system 1 (i.e., the case of the consumer shown in Figure 3(B)).

[0035] When the magnitude of the generated power to be increased or decreased according to the output control is relatively large compared to the maximum generated power of the power generation equipment, reverse power flow according to the output control command value is possible without exceeding the upper limit of the allowable error, as shown in Figure 4(A). However, when the magnitude of the generated power to be increased or decreased according to the output control is relatively small compared to the maximum generated power of the power generation equipment, the maximum received power becomes small, and the control resolution becomes relatively low. Therefore, as shown in Figure 4(B), reverse power flow according to the output control command value becomes difficult, and there is a possibility that the upper limit of the allowable error will be exceeded.

[0036] If the control resolution of various sensors, control circuits, etc. used in power generation equipment is high, the control resolution will not be a problem even if the magnitude of the generated power to be increased or decreased according to output control is relatively small compared to the maximum generated power of the power generation equipment. However, achieving control with high resolution will increase the cost of the device. Therefore, it is not realistic to uniformly increase the control resolution of various sensors, control circuits, etc. used in power generation equipment in preparation for the case where the magnitude of the generated power to be increased or decreased according to output control is relatively small compared to the maximum generated power of the power generation equipment.

[0037] Therefore, in the power supply system 1, the output control value calculation unit 6A uses the correction value stored in the set value storage unit 6C to adjust the output control controller 6B so that the magnitude of the reverse flow power falls below the output control command value. FIG. 5 is a graph comparing the reverse flow before and after adjustment. There are various possible methods for adjusting the output control controller 6B so that the magnitude of the reverse flow power falls below the output control command value. Here, five patterns are illustrated as shown in FIG. 5. In FIG. 5, the dashed line indicates the magnitude of the reverse flow when the power generation equipment is controlled using the output control command value notified by the power server 5 as is, and the solid line indicates the magnitude of the reverse flow when the power generation equipment is controlled using the corrected value of the output control command value notified by the power server 5 as the output control correction value.

[0038] <Pattern 1: Offset (with zero grip)> In FIG. 5(A), a certain correction value is subtracted from the output control command value notified from the power server 5. 5A shows a pattern in which the power generation equipment is controlled using the value obtained by subtracting a certain correction value as the output control correction value. However, in order to prevent excessive restriction of the power generation amount of the power generation equipment, which would result in a forward power flow, in this pattern, the output control correction value is set to zero if it falls below zero. In this pattern, a value obtained by subtracting a certain correction value from the output control command value is input to the output control controller 6B as the output control correction value, and the PCS 4 is controlled. Therefore, as shown in FIG. 5A, reverse power flow is reduced compared to when the power generation equipment is controlled using the output control command value as is. Therefore, even when the maximum receiving power is small, it is possible to minimize the possibility of reverse power flow exceeding the upper limit of the error allowable in output control due to control resolution.

[0039] <Pattern 2: Offset (without zero grip)> FIG. 5(B) shows a pattern in which, like Pattern 1, the power generation equipment is controlled using an output control correction value obtained by subtracting a certain correction value from the output control command value notified by the power server 5. However, in this pattern, the process of setting the output control correction value to zero when the output control correction value falls below zero, as was done in Pattern 1, is not performed. In this pattern, the value obtained by subtracting a certain correction value from the output control command value is input to the output control controller 6B as the output control correction value, and the PCS 4 is controlled. Therefore, as shown in FIG. 5(A), reverse power flow is reduced compared to when the power generation equipment is controlled using the output control command value as is. Therefore, even when the maximum receiving power is small, it is possible to minimize the possibility of reverse power flow exceeding the upper limit of the allowable error in output control due to control resolution. Furthermore, in this pattern, the process of setting the output control correction value to zero when the output control correction value falls below zero is not performed. Therefore, compared to Pattern 1, it is possible to minimize the possibility of reverse power flow exceeding the upper limit of the allowable error in output control, even when the output control command value is near 0%.

[0040] <Pattern 3: Gain> FIG. 5(C) shows a pattern in which the power generation equipment is controlled using an output control correction value obtained by multiplying the output control command value notified by the power server 5 by a constant correction value slightly smaller than 1. In this pattern, the output control command value multiplied by the constant correction value is input to the output control controller 6B as the output control correction value, and the PCS 4 is controlled. Therefore, as shown in FIG. 5(C), reverse power flow is reduced compared to when the power generation equipment is controlled using the output control command value as is. Therefore, even when the maximum receiving power is small, it is possible to minimize the possibility of reverse power flow exceeding the upper limit of the allowable error in output control due to control resolution. In this pattern, as the output control command value approaches 100%, the difference between the output control correction value and the output control command value gradually increases, making it possible to limit reverse power flow according to the magnitude of the output control command value.

[0041] <Pattern 4: Offset + Gain> FIG. 5(D) shows a pattern in which the power generation equipment is controlled using the output control correction value obtained by subtracting and multiplying a certain correction value from the output control command value notified by the power server 5. However, in order to prevent excessive restriction on the power generation amount of the power generation equipment from causing a forward power flow, in this pattern, the output control correction value is set to zero when it falls below zero. In this pattern, the value obtained by subtracting and multiplying the certain correction value from the output control command value is input to the output control controller 6B as the output control correction value, and the PCS 4 is controlled. Therefore, as shown in FIG. 5(D), reverse power flow is reduced compared to when the power generation equipment is controlled using the output control command value as is. Therefore, even when the maximum receiving power is small, it is possible to minimize the possibility of reverse power flow exceeding the upper limit of the error allowable in output control due to the control resolution. In this pattern, as the output control command value approaches 100%, the difference between the output control correction value and the output control command value gradually increases. Therefore, while it is possible to limit reverse power flow according to the magnitude of the output control command value, when the output control command value is near 0%, It is also possible to limit reverse power flow to a certain extent.

[0042] <Pattern 5: Stairs> FIG. 5(E) shows a pattern in which a value obtained by stepwise subtracting the output control command value notified by the power server 5 is used as the output control correction value to control the power generation equipment. In this pattern, the value obtained by stepwise subtracting the output control command value is input to the output control controller 6B as the output control correction value, and the PCS 4 is controlled. Therefore, as shown in FIG. 5(E), reverse power flow is reduced compared to when the power generation equipment is controlled using the output control command value as is. Therefore, even when the maximum receiving power is small, it is possible to minimize the possibility of reverse power flow exceeding the upper limit of the error allowable in output control due to the control resolution. In this pattern, a value obtained by stepwise subtracting the output control command value is used as the output control correction value, thereby reducing the processing load related to the calculation of the output control correction value.

[0043] <Pattern 6: Function> FIG. 5(F) shows a pattern in which the power generation equipment is controlled using an output control correction value calculated by applying the output control command value notified by the power server 5 to a predetermined formula. In this pattern, a value smaller than the output control command value, calculated by applying the output control command value notified by the power server 5 to a predetermined formula, is input to the output control controller 6B as the output control correction value, and the PCS 4 is controlled. Therefore, as shown in FIG. 5(F), reverse power flow is reduced compared to when the power generation equipment is controlled using the output control command value as is. Therefore, even when the maximum receiving power is small, it is possible to minimize the possibility of reverse power flow exceeding the upper limit of the allowable error in output control due to control resolution. Because this pattern uses a formula, for example, by using a function that reflects the complex characteristics of the power generation equipment, it is possible to control the power generation equipment according to the characteristics of the power generation equipment.

[0044] Each pattern has been explained above. In the power supply system 1, because the output control correction value as described above is used, even when the maximum receiving power is small, it is possible to minimize the possibility of reverse power flow exceeding the upper limit of the error allowable in output control due to the control resolution. Note that, in each of the above patterns, even when the output control command value is 100%, the power generation equipment is controlled using the output control correction value obtained by subtracting the correction value from the output control command value. However, the power supply system 1 is not limited to this. In other words, an output control command value of 100% means that reverse power flow is not restricted. Therefore, when the output control command value is 100%, the power generation equipment may be controlled without using the output control correction value. Furthermore, each of the above patterns may be combined as appropriate.

[0045] Furthermore, the magnitude of the adjustment amount, which is the difference between the output control command value and the output control correction value, may be increased or decreased according to the proportion of the maximum received power to the maximum generated power of the power generation facility. If the magnitude of the adjustment amount is increased or decreased in this manner, it becomes possible to control the output of the power generation facility using an output control correction value that corresponds to the degree of impact that the control resolution of the power generation facility has on the reverse power flow.

[0046] Furthermore, in the above embodiment, the minimum load amount "D2" shown in FIG. 3 is a fixed value, but "D2" may be a variable value of self-consumption, which is the power consumption of the load 3 that changes from moment to moment.

[0047] In the above embodiment, the power measurement unit 7 measures the power received by the consumer using an ammeter installed near the power receiving point. However, the power measurement unit 7 may measure the power consumption of the load 3 using an ammeter installed in an electric path connecting the PCS 4 and the load 3. FIG. 6 is a schematic diagram of the power supply system 1 according to this modification. For example, as shown in FIG. 6, If an ammeter is provided in the electrical path connecting the PCS 4 and the load 3, the power measurement unit 7 can measure the power consumption of the load 3. In this modification, in order to measure the magnitude of the reverse power flow, the output control controller 6B of the output control unit 6 acquires the amount of power generated by the power generation facility from the PCS 4. The output control controller 6B can grasp the magnitude of the reverse power flowing to the power grid 2 by subtracting the power consumption of the load 3 from the amount of power generated acquired from the PCS 4.

[0048] <Other> The above embodiment is merely an example, and the present embodiment may be modified as appropriate within the scope of the gist thereof. The processes and means described in this disclosure may be freely combined and implemented as long as no technical contradiction occurs.

[0049] Furthermore, a process described as being performed by one circuit or device may be shared and executed by multiple circuits or devices. Alternatively, a process described as being performed by different circuits or devices may be executed by a single circuit or device. Needless to say, there are various other methods for operating a power generation facility so that the magnitude of the reverse power flow is below the output control command value. For example, instead of using the correction value stored in the set value storage unit 6C, the output control controller 6B adds a predetermined value to the measurement value of the power measurement unit 7, compares the added value with the output control value, and offsets the power generation amount to the negative side. Alternatively, the power generation amount may be offset to the negative side by adding a function to the power generation facility's control device itself to subtract a predetermined value from the command value from the output control unit 6.

[0050] The present application includes the following additional matters. <Appendix 1> A power supply system (1) for a consumer capable of transmitting surplus power to a power grid, Power generation facilities (4); a control device (6) that controls the power generation facility, The control device controls the power generation facility so that the magnitude of the reverse power flow transmitted from the consumer to the power grid is below an output control value notified by a higher-level device (5). Power supply system (1). <Appendix 2> the control device (6) controls the power generation equipment so that a ratio of a reverse power flow to an upper limit power that can be transmitted to the power grid at the consumer falls below the output control value. 1. The power supply system (1) according to claim 1. <Appendix 3> The upper limit power is a value obtained by subtracting the minimum load amount for self-consumption from the maximum received power in the customer's contract. 2. The power supply system (1) according to claim 2. <Appendix 4> The control device (6) an output control unit (6B) that controls the power generation facility so that the magnitude of the reverse power flow complies with the output control value; an adjustment unit (6A) that adjusts the output control unit so that the magnitude of the reverse power flow is below the output control value, the adjustment unit adjusts the output control unit by inputting the corrected value of the output control value to the output control unit so that the magnitude of the reverse power flow is less than the output control value. A power supply system (1) according to any one of appendices 1 to 3. <Appendix 5> The control device (6) an output control unit (6B) that controls the power generation facility so that a difference between the amount of power generated by the power generation facility and the power consumption value of load consumption conforms to the output control value; an adjusting unit (6A) that adjusts the output control unit so that the difference between the power generation amount and the load consumption is less than the output control value; The calculation result of the adjustment unit is input to the output control unit, and the output control unit is adjusted so that the difference between the power generation amount and the load consumption is less than the output control value. A power supply system (1) according to any one of claims 1 to 3. <Appendix 6> the adjusting unit changes an adjustment amount when adjusting the output control unit in accordance with a ratio of an upper limit power that can be transmitted to the power grid at the consumer to a power generation capacity of the power generation facility. 6. The power supply system (1) according to claim 4 or 5. <Appendix 7> The control device (6) offset from the output control value, or multiplying the output control value by a proportional gain less than 1; The output control value is determined in stages according to the output control value. by applying the output control value to a mathematical formula, or The value determined by the combination of these is used to control the power generation equipment, thereby controlling the power generation equipment so that the magnitude of the reverse power flow is less than the output control value. A power supply system (1) according to any one of appendices 1 to 6. <Appendix 8> A power control device (6) for a consumer that can transmit surplus power to a power grid, controlling the power generation equipment so that the magnitude of the reverse power flow transmitted from the consumer to the power grid is below an output control value notified by a higher-level device; Power control device (6). [Explanation of symbols]

[0051] 1. Power supply system 2.Power system 3. Load 4 PCS 5. Power Server 6. Output control unit 7. Power measurement section 6A··Output control value calculation section 6B Output Controller 6C Setting value storage section

Claims

1. A power supply system for a consumer that can transmit surplus power to a power grid, Power generation facilities, a control device that controls the power generation facility, the control device controls the power generation facility so that the magnitude of the reverse power flow transmitted from the consumer to the power grid is below an output control value notified by a higher-level device. Power supply system.

2. the control device controls the power generation facility so that a ratio of a reverse power flow to an upper limit power that can be transmitted to the power grid at the consumer falls below the output control value. The power supply system according to claim 1 .

3. The upper limit power is a value obtained by subtracting the minimum load amount for self-consumption from the maximum received power in the customer's contract. The power supply system according to claim 2 .

4. The control device an output control unit that controls the power generation facility so that the magnitude of the reverse power flow conforms to the output control value; an adjustment unit that adjusts the output control unit so that the magnitude of the reverse power flow is less than the output control value, the adjustment unit adjusts the output control unit by inputting the corrected value of the output control value to the output control unit so that the magnitude of the reverse power flow is less than the output control value. The power supply system according to claim 1 .

5. The control device an output control unit that controls the power generation facility so that a difference between the amount of power generated by the power generation facility and the power consumption value of load consumption conforms to the output control value; an adjusting unit that adjusts the output control unit so that the difference between the power generation amount and the load consumption is less than the output control value, The calculation result of the adjustment unit is input to the output control unit, and the output control unit is adjusted so that the difference between the power generation amount and the load consumption is less than the output control value. The power supply system according to claim 1 .

6. the adjusting unit changes an adjustment amount when adjusting the output control unit in accordance with a ratio of an upper limit power that can be transmitted to the power grid at the consumer to a power generation capacity of the power generation facility. The power supply system according to claim 4 .

7. The control device offset from the output control value, or multiplying the output control value by a proportional gain less than 1; The output control value is determined in stages according to the output control value. by applying the output control value to a mathematical formula, or The value determined by the combination of these is used to control the power generation equipment, thereby controlling the power generation equipment so that the magnitude of the reverse power flow is less than the output control value. The power supply system according to any one of claims 1 to 6.

8. A power control device for a consumer that can transmit surplus power to a power grid, The magnitude of the reverse power flow transmitted from the consumer to the power grid is notified from the host device. Controlling the power generation equipment so that the output is below the output control value Power control device.

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