JP2019041528A - Power source controller, power source control method, and power source control program - Google Patents

Abstract

To wholly raise the operation efficiency of a power source system having a plurality of power converter rated outputs.SOLUTION: A power source controller according to an embodiment hereof comprises: a request-acquisition part which acquires a request power showing an electric power to supply a load from a power source system having a plurality of combinations of power storage devices and power converters; a selecting part which selects, from the power converters, at least one power converter to be operated to discharge based on the request power, and sets an output power of each of at least one power converter; and an instruction part which sends a discharge instruction toward each of the at least one selected power converter. Of the power converters, at least two power converters are different from each other in rated output. The selecting part sets an output power of each of the at least one power converter to no less than a limit output based on the request power.SELECTED DRAWING: Figure 3

Description

  One aspect of the present invention relates to a power control device that controls power supply from a plurality of power storage devices, a power control method, and a power control program.

  A method of controlling power supply from a power supply system provided with a plurality of power storage devices is conventionally known. For example, Patent Document 1 describes a power storage system in which a power storage unit, which is a plurality of pairs of a storage battery and a converter, is connected in parallel to a power system. The storage system includes a power distribution determination unit that determines the number of operating storage units. The power distribution determination unit compares the limit output when the conversion efficiency of the converter is equal to or higher than the reference efficiency with the total charge / discharge power, and when the total charge / discharge power is equal to or more than the limit output, Determine the number of operating units so that the output is equal to or higher than the limit output.

JP, 2015-162917, A

  The rated outputs of the plurality of power converters included in the power supply system may not all be the same. If power converters with different rated outputs are present in a power supply system, simply determining the number of operating units may not be sufficient to operate the power supply system efficiently. Therefore, it is desirable to increase the operation efficiency of a power supply system in which a plurality of rated outputs of a power converter exist.

  According to one aspect of the present invention, there is provided a power control apparatus including: a request acquisition unit for acquiring a required power indicating power to be supplied toward a load from a power supply system including a plurality of sets of a storage device and a power converter; Based on the plurality of power converters, a selection unit for selecting at least one power converter to be discharged and setting an output power of each of the at least one power converter, and at least one selected power converter And at least one of the plurality of power converters having different rated outputs among the plurality of power converters, and the selection unit is configured to transmit at least one of the plurality of power converters based on the required power. Set the output power of each of the two power converters above the critical output.

  A power control method according to one aspect of the present invention is a power control method executed by a power control device, which is to be supplied from a power system including a plurality of sets of a power storage device and a power converter toward a load. At least one power converter to be subjected to discharge operation is selected from the plurality of power converters based on the required power acquisition step of acquiring the required power to be shown and the required power, and the output power of each of the at least one power converter is set Selection step, and an instruction step of transmitting a discharge instruction toward each of the at least one selected power converter, wherein the rated output of each of the plurality of power converters is mutually different. Differently, in the selection step, the output power of each of the at least one power converter is set above the limit output based on the required power.

  A power supply control program according to an aspect of the present invention includes a request acquisition step of acquiring a required power indicating power to be supplied toward a load from a power supply system including a plurality of sets of a power storage device and a power converter; Based on the plurality of power converters, selecting at least one power converter to be discharged and setting an output power of each of the at least one power converter, and at least one selected power converter And causing the computer to execute an instruction step of transmitting a discharge instruction toward each of the plurality of power converters, wherein the rated output is different between at least two of the plurality of power converters, and the selection step is performed based on the required power. The output power of each of the at least one power converter is set above the limit output.

  In such an aspect, the output power is set to the critical output or more for all of the power converters selected to cause the discharge operation. Since the discharge operation of each power converter satisfies the reference efficiency, the operation efficiency of the power supply system can be increased as a whole.

  According to one aspect of the present invention, the operation efficiency of the power supply system in which a plurality of rated outputs of the power converter exist can be raised as a whole.

It is a figure showing typically an example of composition of a power supply system. It is a graph which shows an example of the conversion efficiency of a power converter. It is a figure which shows the function structure of the integrated controller (power supply control apparatus) which concerns on embodiment. It is a figure which shows an example of power converter information. It is a flowchart which shows operation | movement of the integrated controller (power supply control apparatus) which concerns on embodiment. It is a figure which shows an example of the discharge according to the required electric power. It is a figure which shows another example of the discharge according to the required power. It is a figure which shows the structure of the power supply control program which concerns on embodiment.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the attached drawings. In the description of the drawings, the same or equivalent elements will be denoted by the same reference symbols, without redundant description.

[Overall configuration of power supply system]
The power control device according to the embodiment is a device that functions as part of a power supply system 1 that manages electricity generated using renewable energy. Before describing the power supply control device, an overview of the power supply system will be described.

  The power supply system 1 can be used in various places such as, for example, a home, an office, a factory, and a farm. A home energy management system (HEMS) is an example of the home power supply system 1.

  FIG. 1 is a view schematically showing an example of the configuration of a power supply system 1. The power supply system 1 includes at least one power generation device 10, a plurality of power storage devices 20, and a plurality of power converters 30. The power supply system 1 can supply the load 2 with the power generated by the power generation device 10 or the power output from the power storage device 20. A load is a collection of one or more devices or devices that consume power, for example, a collection of one or more various household or business electrical devices. A contactor 3 is provided between the power supply system 1 and the load 2 for connecting or disconnecting an electric path between the two. When the power supply system 1 and the load 2 are connected by the contactor 3, the power supply system 1 can supply power to the load 2.

  The power generation device 10 is a device that generates power using renewable energy. The power generation method is not limited, and thus, the type of the power generation device 10 is not limited. For example, the power generation device 10 may be a solar power generator, a wind power generator, or the like.

  The storage device 20 is a device that converts the electricity generated by the power generation device 10 into chemical energy and stores it, and can be charged and discharged. Power storage device 20 can also be used to equalize fluctuations in DC power generated by power generation device 10. As an example of the power storage device 20, a storage battery such as a lead storage battery can be mentioned. The power storage device 20 may include control functions such as a battery control unit (BCU).

  The power converter 30 is a device that performs bi-directional or uni-directional conversion between alternating current power and direct current power. Each power converter 30 has a DC terminal connected to a DC (Direct Current) bus through which direct current flows, and an AC terminal connected to an AC (Alternating Current) bus through which alternating current flows. The power converter 30 may be, for example, a power conditioning system (PCS) or an inverter.

  Power converter 30 is electrically connected to a corresponding power storage device 20 via a DC bus, and controls charging / discharging of power storage device 20. Power converter 30 stores the electricity flowing from power generation device 10 in power storage device 20 in the charge mode, discharges power storage device 20 in the discharge mode to supply power to the outside, and performs charge / discharge in the stopped state. Absent. Since power supply system 1 includes a plurality of power storage devices 20 and a plurality of power converters 30, power supply system 1 includes a plurality of sets of power storage devices 20 and power converters 30. This set can also be referred to as a storage unit. In the example of FIG. 1, the power supply system 1 includes three sets of power storage devices 20 and power converters 30 (three power storage units), but the number of sets may be any number.

  In the example illustrated in FIG. 1, the power supply system 1 includes a heat pump unit 80 that uses hot power of the power generation device 10 to boil hot water. However, the heat pump unit 80 is not an essential component and may be omitted.

  In the example illustrated in FIG. 1, the devices and devices that constitute the power supply system 1 are provided in the form of being divided and stored in a plurality of containers 90. By using this container 90, for example, the power storage device 20 and the power converter 30 can be easily added to the power supply system 1. FIG. 1 shows that containers 90A, 90B, and 90C are already installed, and a container 90D can be expanded. However, the use of the container 90 is not essential, and the power supply system 1 may be constructed in any manner.

  The number of each of the power generation device 10, the power storage device 20, and the power converter 30 is not limited. For example, the number of power generation devices 10 may be one or three or more. The number of each of power storage device 20 and power converter 30 may be any number as long as it is plural.

  An electrical connection between devices in the power supply system 1 will be described. In the following, for the convenience of description, the two power generation devices 10 shown in FIG. 1 are distinguished as power generation devices 10A and 10B, and the three power storage devices 20 are distinguished as power storage devices 20A, 20B and 20C. The power converters 30 of one are identified as power converters 30A, 30B, 30C, 30D.

  The power supply system 1 includes an AC bus 40 connected to the load 2 via the contactor 3 and crossing between containers 90. The power generation device 10A is connected to the DC terminal of the power converter 30A via the DC bus 51, and the AC terminal of the power converter 30A is connected to the AC bus 40. Power storage device 20A is connected to the DC terminal of power converter 30B via DC bus 52, and the AC terminal of power converter 30B is connected to AC bus 40. Power converter 30C is a hybrid type (for example, a hybrid inverter) connected to both power generation device 10B and power storage device 20B. The power generation device 10B is connected to the first DC terminal of the power converter 30C via the DC bus 53. Power storage device 20B is connected via DC bus 54 to the second DC terminal of power converter 30C. The AC terminal of the power converter 30C is connected to the AC bus 40. Power storage device 20C is connected to the DC terminal of power converter 30D via DC bus 55, and the AC terminal of power converter 30D is connected to AC bus 40. The heat pump unit 80 is connected to the AC bus 40.

  The devices and devices in the power supply system 1 are controlled by a plurality of hierarchically configured controllers. Each controller is a computer (e.g. a microcomputer) comprising a processor, a memory and a communication interface. The processor is, for example, a CPU, and the memory is, for example, a flash memory, but the types of hardware devices that configure the controller are not limited to these, and may be selected arbitrarily. Each function of the controller is realized by the processor executing a program stored in the memory. For example, the processor executes a predetermined operation on data read from the memory or data received via the communication interface, and outputs the operation result to another controller or device, thereby the other controller or device. Control. Alternatively, the processor stores the received data or operation result in the memory.

  The controller group in the power supply system 1 includes one general controller 100, a plurality of head local controllers 210, and a plurality of local controllers 220. The integrated controller 100 controls the entire power supply system 1 in an integrated manner. The head local controller 210 centrally controls one device group. In the example of FIG. 1, one head local controller 210 is provided for each container 90, and each head local controller 210 centrally controls devices in the container 90. The local controller 220 directly controls one or more devices. Each of these controllers may be configured by a single computer or may be configured by a set of multiple computers (that is, a distributed system).

  These controllers are communicably connected to each other via a communication line 140. The general controller 100 further connects to the contactor 3 via the communication line 140. Each local controller 220 is communicably connected to the corresponding device via the communication line 140. The communication line 140 may be wireless or wired, or may be a mixture of wireless and wired.

[Power converter]
Each of power converters 30 (power converters 30B, 30C, and 30D in the example of FIG. 1) is directly connected to power storage device 20. The rated outputs of the at least two power converters 30 among the plurality of power converters 30 are different from each other. In other words, the rated output of one power converter 30 in the power supply system 1 is different from the rated output of at least one of the other power converters 30. That is, in the power supply system 1, a plurality of types of rated outputs of the power converter 30 exist. Here, the rated output is the maximum power (maximum charging power and discharging power) that the power converter 30 can stably output. The rated outputs may be different among all the power converters 30. Alternatively, in the case where the power supply system 1 includes three or more power converters 30, the rated output may be the same among some of the power converters 30. For example, in the case where the power supply system 1 includes three power converters 30 (in the example of FIG. 1, the power converters 30B, 30C, and 30D), each of the three power converters 30 is another power converter 30. May have a different rated output. Alternatively, the two power converters 30 may have the same rated output, and the remaining one power converter may have another rated output.

  The rated output of each power converter 30 may be determined in any manner, for example, in consideration of the power consumption of the load 2. Alternatively, the individual rated power may be determined in consideration of the availability of the market in addition to the power consumption of the load 2.

  Alternatively, the individual rated output may be determined based on the conversion efficiency (operating efficiency) of the power converter 30 in addition to the power consumption of the load 2. In general, the operation of power converter 30 is controlled such that the conversion efficiency of power between alternating current and direct current is equal to or higher than a predetermined threshold. The threshold of this conversion efficiency is called reference efficiency. Further, the lower limit value of the output power of the power converter 30 when the conversion efficiency is equal to or higher than the threshold value is referred to as a limit output. Thus, the limit output is the output power corresponding to the reference efficiency. Assuming that the ratio of the limit output to the rated output is called the limit output ratio, the limit output ratio corresponds to the reference efficiency. If the output power of the power converter 30 is equal to or higher than this limit output, the conversion efficiency (operating efficiency) of the power converter 30 meets the reference efficiency, and if the output power is less than the limit output, the conversion efficiency does not meet the reference efficiency. FIG. 2 is a graph showing an example of the conversion efficiency of the power converter 30. As shown in FIG. The horizontal axis indicates the ratio (%) of output power to rated output, and the vertical axis indicates power conversion efficiency (%). This graph shows that the reference efficiency η is 85% and the limit power ratio ρ is 20%.

For example, the rated output of each power converter 30 can be determined as follows based on the limit power ratio common to a plurality of power converters 30. Assuming that the power converter 30 having the smallest rated output P _{r, 1} among the plurality of power converters 30 is the first power converter 30, the rated output P _{r, n} of the second and subsequent power converters 30 is It may be defined by the following formula (1). Here, n is an ordinal number for identifying the power converter 30, and ρ is a limit power ratio (%).

It is assumed that the power supply system 1 includes three power converters 30, and ρ = 20 (%). In this case, the equation (1) representing the rated outputs P _{r, 2} and P _{r, 3} of the second and third power converters 30 is represented by the following equations (2) and (3), respectively.
P _{r, 2} = 4 × P _{r, 1} (2)
P _{r, 3} = 4 × (P _{r, 1} + P _{r, 2} ) = 20 × P _{r, 1} (3)

Therefore, the ratio of the rated output of these three power converters 30 is P _{r, 1} : P _{r, 2} : P _{r, 3} = 1: 4: 20. If P _{r, 1} = 10 (kW), then P _{r, 2} = 40 (kW) and P _{r, 3} = 200 (kW).

The setting method of the rated output based on Formula (1) can be said as follows. The plurality of power converters 30 include at least one first power converter and a second power converter whose rated output is larger than that of the first power converter. Hereinafter, the first power converter is referred to as a "low output power converter", and the second power converter is referred to as a "high output power converter". In this case, the rated output of the high output power converter is set based on the rated output of at least one low output power converter and the limit output ratio common to the plurality of power converters. For example, if the high output power converter is the second power converter, then the low output power converter is one (the first power converter). In this case, the rated output P _{r, 2} is set based on the rated output P _{r, 1} and the limit output ratio ρ. Similarly, if the high output power converter is the third power converter, then the low output power converters are two (first and second power converters). In this case, the rated output P _{r, 3} is set based on the rated output P _{r, 1} , P _{r, 2} and the limit output ratio ρ.

  The response speed may be different between at least two power converters 30 among the plurality of power converters 30. In other words, the response speed of one power converter 30 in the power supply system 1 may be different from the response speed of at least one of the other power converters 30. That is, in the power supply system 1, multiple types of response speeds may exist for the power converter 30. Here, the response speed is a value indicating the speed at which the actual output power of the power converter 30 changes from the current value to the specified value. In short, it can be said that the response speed is the speed of reaction of the power converter 30. The fast response speed of the power converter 30 means that the output power of the power converter 30 reaches the designated value in a short time, that is, the ability to follow the designated value is high. The response speed may be different among all the power converters 30. Alternatively, in the case where the power supply system 1 includes three or more power converters 30, the response speed may be the same among some of the power converters 30. For example, in the case where the power supply system 1 includes three power converters 30 (in the example of FIG. 1, the power converters 30B, 30C, and 30D), each of the three power converters 30 is another power converter 30. May have a different response speed. Alternatively, two power converters 30 may have the same response speed, and one remaining power converter may have another response speed.

[Electric storage device]
The rated capacities of the individual power storage devices 20 may be determined in any manner, and may be determined in consideration of, for example, the power consumption of the load 2 and the performance of the power generation device 10. The rated capacity is the amount of electricity that can be stored by the power storage device 20 under predetermined conditions. The rated capacities may be the same among all power storage devices 20 or may be different among all power storage devices 20. Alternatively, in the case where power supply system 1 includes three or more power storage devices 20, the rated capacities may be the same among some of power storage devices 20. Each rated capacity may be determined based on the rated output of the corresponding power converter 30. For example, the smaller the rated output of the power converter 30, the more the storage device 20 connected to the power converter 30. Individual rated capacities may be set to increase the rated capacities. Therefore, power storage device 20 having the largest rated capacity in power supply system 1 may be connected to power converter 30 having the smallest rated output in power supply system 1. Alternatively, individual rated capacities may be set such that the smaller the rated output of power converter 30 is, the smaller the rated capacity of power storage device 20 connected to that power converter 30 becomes.

[Configuration of integrated controller]
One of the features of the power supply system 1 lies in the method of supplying power to the load 2, which feature is particularly realized by the general controller 100. In the present embodiment, the power supply control device according to the present invention is applied to the general controller 100. The function and configuration of the general controller 100 related to the power supply to the load 2 will be described below.

  FIG. 3 is a diagram showing a functional configuration of the general controller 100 according to the embodiment. The central controller 100 includes a processor 101, a memory 102, and a communication interface 103 as hardware elements.

  The processor 101 functions as the request acquisition unit 111, the selection unit 112, and the instruction unit 113. The request acquisition unit 111 is a functional element that acquires the required power indicating the power to be supplied from the power supply system 1 toward the load 2. Selection unit 112 performs at least one power converter for performing a discharge operation from a plurality of power converters 30 (power converters 30B, 30C, and 30D in the example of FIG. 1) connected to power storage device 20 based on the required power. It is a functional element which selects 30. The instruction unit 113 is a functional element that transmits a discharge instruction to each of the selected power converters 30. The discharge instruction is a data signal for causing the power converter 30 to discharge.

  The memory 102 stores information necessary for the operation of the processor 101. For example, memory 102 stores power converter information 121 and selection rules 122.

  The power converter information 121 is information on the specification of each power converter 30. In the present embodiment, the power converter information 121 indicates the rated output and response speed of each power converter 30. Each record of power converter information 121 includes a power converter ID, a rated output, and a response speed. The power converter ID is an identifier for uniquely identifying the power converter 30. FIG. 4 is a diagram showing an example of the power converter information 121. As shown in FIG. In this example, the power converter information 121 indicates the rated output and the response speed for the three power converters 30 whose IDs are A, B, and C, respectively.

  The selection rule 122 is information that describes a rule for selecting the power converter 30 based on the required power. The description method of the selection rule 122 is not limited. For example, the selection rule 122 may be represented by any one of a formula, an algorithm, and a correspondence table, or may be represented by any two or more combinations of a formula, an algorithm, and a correspondence table. The selection rule 122 may be part of a program executed by the processor 101.

  The power converter information 121 and the selection rule 122 may be rewritable. When the power converter 30 is added, replaced, or removed in the power supply system 1, the administrator rewrites the power converter information 121 and the selection rule 122 in the memory 102 according to the change of the power converter 30. For example, the administrator accesses the general controller 100 with a computer for management (not shown) via a predetermined communication network (not shown), and new power converter information 121 reflecting the change of the power converter 30. And transfer the selection rule 122 to the general controller 100. By this transfer, the power converter information 121 and the selection rule 122 in the memory 102 are rewritten.

  The communication interface 103 cooperates with the processor 101 to execute transmission and reception of data. For example, the communication interface 103 outputs a discharge instruction to at least one power converter 30 in cooperation with the instruction unit 113.

[Operation of integrated controller]
The operation of the general controller 100 and the power control method according to the present embodiment will be described with reference to FIGS. 5 to 7. FIG. 5 is a flowchart showing an example of the operation of the general controller 100. 6 and 7 show examples of discharge according to the required power.

  In step S11, the request acquisition unit 111 acquires the required power (request acquisition step). The request acquisition unit 111 may obtain the required power by calculation. For example, the request acquisition unit 111 may receive the power information on the load 2 side from the sensor on the load 2 side, and obtain the required power by obtaining the power to be supplied to the load 2 based on the power information. Alternatively, the request obtaining unit 111 may receive data indicating the required power from another device or system (not shown). Thus, the method of acquiring the required power is not limited.

  In step S12, the selection unit 112 selects the power converter 30 to be subjected to the discharge operation based on the required power, and determines the output power of each power converter 30 (selection step). Specifically, the selection unit 112 executes the selection of the power converter 30 and the setting of the output power based on the required power so that the output power of each power converter 30 to be subjected to the discharge operation becomes equal to or higher than the limit output. Do. Here, the output power means the power provided from the power storage device 20 corresponding to the selected power converter 30 and output to the AC bus 40. Information necessary for the selection of the power converter 30 and the setting of the output power is stored in the memory 102 in advance. For example, the selection rule 122 may include the limit power ratio, and the power converter information 121 may further include the limit output of each power converter 30.

  The selection method of the power converter 30 and the determination method of the output power of the selected power converter 30 are not limited, and various methods may be adopted. When there is a plurality of options for the power converter 30 and the output power when a certain required power is given, the selection unit 112 can select any one option.

For example, it is assumed that rated outputs P _{r, 1} , P _{r, 2} and P _{r, 3 of} power converters A, B and C are 10 kW, 40 kW and 200 kW, respectively, and the limit output ratio is 20%. Therefore, the limit outputs of the power converters A, B and C are 2 kW, 8 kW and 40 kW, respectively. In this case, the selection unit 112 can select the power converter 30 as follows according to the required power _Preq . Hereinafter, the output powers of the power converters A, B and C will be referred to as P _{req, 1} , P _{req, 2} and P _{req, 3} , respectively.

In the case of P _req <8 kW, the selection unit 112 selects only the power converter A and sets its output power as P _{req, 1} = P _req . If the required power is less than 2 kW, the output power of the power converter A will be less than the limit output, so the reference efficiency can not be satisfied, but this can not but be tolerated.

In the case of P _req kW8 kW, the selection unit 112 can adopt one of a plurality of options according to the magnitude of the required power. There are seven options for the combination of power converters 30:
Option H1: Power converter A
Option H2: power converters A, B
Option H3: power converters A, C
Option H4: Power converter B
Option H5: power converters B, C
Option H6: Power converter C
Option H7: power converters A, B, C

For example, in the case of P _req = 10 kW, the selection unit 112 may select only the power converter A and set the output power to P _{req, 1} = 10 kW (option H1). Alternatively, the selection unit 112 may select the power converters A and B, and set the output power of each as P _{req, 1} = 2 kW and P _{req, 2} = 8 kW (option H2). Alternatively, the selection unit 112 may select only the power converter B and set its output power to P _{req, 2} = 10 kW (Option H4).

As another example, in the case of P _req = 100 kW, the selection unit 112 selects the power converters A and C, and sets the respective output powers to P _{req, 1} = 5 kW and P _{req, 3} = 95 kW. You may (option H3). Alternatively, the selection unit 112 may select the power converters B and C, and set their output powers to P _{req, 2} = 40 kW and P _{req, 3} = 60 kW (option H5). Alternatively, the selection unit 112 may select only the power converter C and set its output power to P _{req, 3} = 100 kW (option H6). Alternatively, the selection unit 112 selects the power converters A, B, and C, and sets the respective output powers to P _{req, 1} = 10 kW, P _{req, 2} = 30 kW, P _{req, 3} = 60 kW. Good (Option H7). Naturally, if the output power of each selected power converter 30 is equal to or higher than the limit output, the distribution amount of required power to each power converter 30 is not limited to these examples.

  When there are a plurality of options for the selection of the power converter 30 and the determination of the output power, criteria for adopting one of the options may be arbitrarily determined. This criterion may be included in the selection rules 122. For example, the selection unit 112 may select the power converter 30 so as to minimize the number of power converters 30 to be operated in a discharging operation. Alternatively, the selection unit 112 may select the power converter 30 such that the average output rate of the power converter 30 to be operated in the discharging operation is maximized. Here, the output rate is the ratio of the output power to the rated output, and the average output rate is the average of the output rates of the one or more power converters 30 to be operated in the discharge mode.

  If the response speed is different between the two or more selected power converters 30, the selection unit 112 selects one of the power converters 30 having a high response speed to compensate for the response delay of the power converter 30 having a slow response speed. The output power may be adjusted. Hereinafter, the power converter with the slower response speed is referred to as the “low response power converter”, and the power converter with the faster response speed (the power converter with a faster response speed than the low response power converter) is referred to as “high It is called a response power converter. The response delay is a phenomenon in which the actual output power of the power converter 30 requires a certain amount of time without instantaneously reaching a designated value (output power indicated by the discharge instruction). When the low response power converter is included in the selected power converter 30, the total output power from the power supply system 1 (the total output power of the selected power converter 30) deviates from the required power Time will come. This divergence time depends on the response speed of the low response power converter. The response delay compensation is control that eliminates or reduces the difference between the total output power from the power supply system 1 and the required power by adjusting the output power of the high response power converter.

The response delay and its compensation will be described with reference to FIG. In FIG. 6, an example (a) shows the case where compensation of response delay is not performed, and an example (b) shows the case where the compensation is performed. In any of the examples, the horizontal axis of the graph indicates time (seconds), and the vertical axis indicates output power (kW). Further, the required power P _req is indicated by a thick solid line in both graphs. In both of the examples (a) and (b), the selection unit 112 selects the power converters A and B, and sets their respective output powers to P _{req, 1} = Pa, P _{req, 2} = Pb, for 10 seconds. It is assumed that the power converters A and B start the discharge operation according to the discharge instruction at the time point of. In addition, it is assumed that the power converter A is a low response power converter and the power converter B is a high response power converter.

In the example (a), the power converter B reaches the designated output power Pb immediately after the start of the discharge operation. However, the power converter A spends more than 30 seconds to reach the designated output power Pa. Therefore, the time until the required power is satisfied depends on the response speed of the power converter A, and the section T does not satisfy the required power P _{req when} viewed as the entire power supply system 1. In order to eliminate or reduce the response delay, the selection unit 112 is configured of the power converter B (high response power converter) until the output power of the power converter A (low response power converter) reaches Pa. By adjusting the output power according to the output power of the power converter A, the output power of the power supply system 1 as a whole satisfies the required power P _req . In the example (b), the output power of the power converter B is about (Pa + Pb) immediately after the start of the response operation, and then drops to Pb in response to the output power of the power converter A approaching Pa. To go. As a result of this adjustment, the output power of the entire power supply system 1 satisfies the required power P _req immediately after the start of the discharge operation.

FIG. 7 shows an example of response delay according to a more complicated change in required power and its compensation. In FIG. 7, an example (a) represents the case where the response delay compensation is not performed, and an example (b) represents the case where the compensation is performed. In both graphs, the rated output P _{r, 1} of the power converter A is indicated by a dashed dotted line. Also in these examples, it is assumed that the power converter A is a low response power converter and the power converter B is a high response power converter.

In the example (a), since the time until the required power is satisfied depends on the response speed of the power converter A, a deviation occurs between the required power P _req and the actual output power when viewed as the entire power supply system 1. For example, the output power temporarily falls below the required power _Preq or temporarily exceeds the required power _Preq . Therefore, as shown in the example (b), the selection unit 112 converts the output power of the power converter B (high response power converter) into the power converter A (low response power converter) each time the required power P _req changes. The response delay of the power converter A is compensated by adjusting according to the output power of.

  Although FIG. 6 and FIG. 7 show an example in which two power converters 30 are selected for discharge operation, the response delay can also be compensated when three or more power converters 30 are selected. . For example, the selection unit 112 selects the power converter 30 having the fastest response speed among the selected power converters 30 as the high response power converter. Then, the selection unit 112 adjusts the output power of the high response power converter to compensate for the response delay of another power converter 30 (low response power converter), whereby the output of the entire power supply system 1 is achieved. Make the power meet the required power in a shorter time.

  In step S13, the instruction unit 113 transmits a discharge instruction to each of the selected one or more power converters 30 (instruction step). “Transmit a discharge instruction to the power converter 30” refers to the power converter 30 or another device corresponding to the power converter 30 in order to cause the power converter 30 to perform a discharge operation. It means sending a discharge instruction. In the present embodiment, the instruction unit 113 transmits a discharge instruction to the one or more local controllers 220 corresponding to the selected one or more power converters 30 via the communication line 140. The discharge instruction includes the IP address of the local controller corresponding to the selected power converter 30 and the output power of the power converter 30. When compensating for the response delay, the discharge instruction for the high response power converter is information necessary for the compensation (for example, the initial value of the output power and the unit time until the final output power). The amount of change in output power) may be included. The local controller 220 controls the corresponding power converter 30 in accordance with the received discharge instruction. The discharge instruction is transmitted to power converter 30 directly or indirectly, and power converter 30 outputs a specified amount of power from power storage device 20 to AC bus 40.

  The output power of the power converter 30 which is not selected is 0, and the power converter 30 will not continue the discharge operation or will stop the discharge operation. The instruction unit 113 transmits a stop instruction to the power converter 30 for stopping the discharge operation. Similar to the discharge instruction, the stop instruction may be transmitted to the power converter 30 or may be transmitted to another device corresponding to the power converter 30. In the present embodiment, the instruction unit 113 transmits a stop instruction to the local controller 220 corresponding to the power converter 30 for stopping the discharge operation. The stop instruction includes the IP address of the local controller corresponding to the power converter 30 to be stopped. The local controller 220 stops the power converter 30 according to the received stop instruction.

  The processes of steps S11 to S13 may be repeatedly executed according to the change of the required power.

[program]
FIG. 8 is a diagram showing a configuration of a power control program P1 for causing a computer to function as the general controller 100. The power control program P1 includes a main module P10, a request acquisition module P11, a selection module P12, and an instruction module P13. The main module P10 is a part that centrally controls the power supply from the power supply system. By executing the request acquisition module P11, the selection module P12, and the instruction module P13, the request acquisition unit 111, the selection unit 112, and the instruction unit 113 are realized. The power control program P1 may further include at least one of the power converter information 121 and the selection rule 122.

  The power control program P1 may be provided after being fixedly recorded on a tangible recording medium such as a CD-ROM, a DVD-ROM, or a semiconductor memory. Alternatively, the power control program P1 may be provided via a communication network as a data signal superimposed on a carrier wave. The provided power control program P1 is stored, for example, in the memory 102.

[effect]
As described above, the power supply control device according to one aspect of the present invention acquires a request for acquiring the required power indicating the power to be supplied to the load from the power supply system including the plurality of sets of the power storage device and the power converter. And a selection unit for selecting at least one power converter to be subjected to discharge operation from the plurality of power converters based on the required power, and setting an output power of each of the at least one power converter, and And an instruction unit for transmitting a discharge instruction to each of at least one power converter, wherein the rated output is different between at least two of the plurality of power converters, and the selecting unit Setting the output power of each of the at least one power converter above the limit output.

  A power control method according to one aspect of the present invention is a power control method executed by a power control device, which is to be supplied from a power system including a plurality of sets of a power storage device and a power converter toward a load. At least one power converter to be subjected to discharge operation is selected from the plurality of power converters based on the required power acquisition step of acquiring the required power to be shown and the required power, and the output power of each of the at least one power converter is set Selection step, and an instruction step of transmitting a discharge instruction toward each of the at least one selected power converter, wherein the rated output of each of the plurality of power converters is mutually different. Differently, in the selection step, the output power of each of the at least one power converter is set above the limit output based on the required power.

  A power supply control program according to an aspect of the present invention includes a request acquisition step of acquiring a required power indicating power to be supplied toward a load from a power supply system including a plurality of sets of a power storage device and a power converter; Based on the plurality of power converters, selecting at least one power converter to be discharged and setting an output power of each of the at least one power converter, and at least one selected power converter And causing the computer to execute an instruction step of transmitting a discharge instruction toward each of the plurality of power converters, wherein the rated output is different between at least two of the plurality of power converters, and the selection step is performed based on the required power. The output power of each of the at least one power converter is set above the limit output.

  In such an aspect, the output power is set to the critical output or more for all of the power converters selected to cause the discharge operation. Since the discharge operation of each power converter satisfies the reference efficiency, the operation efficiency of the power supply system can be increased as a whole.

  In the power supply control device according to another aspect, the response speed is different between at least two power converters among the plurality of power converters, and the selection unit responds more than the low response power converter and the low response power converter The output power of the high response power converter may be adjusted to compensate for the response delay of the low response power converter when selecting two or more power converters including a high speed and high response power converter. . By flexibly controlling the output power of the power converter whose response speed is relatively fast, it is possible to make the output power of the entire power supply system meet the required power more quickly.

  In the power supply control device according to another aspect, the plurality of power converters include at least one low output power converter and a high output power converter having a rated output larger than at least one low output power converter. The rated output of the high output power converter may be set based on the rated output of the at least one low output power converter and the limit output ratio common to the plurality of power converters. By setting the rated output of the power converter in this manner, the power supply system can be efficiently operated as a whole, even when the output power from each power converter is small.

  In the power supply control device according to another aspect, the plurality of power converters include a low output power converter and a high output power converter having a rated output larger than the low output power converter, and connected to the low output power converter The rated capacity of the first power storage device may be larger than the rated capacity of the second power storage device connected to the high output power converter. Generally, in 80% of the operating time of the power supply system, the required output to the power supply system is 50% or less of the maximum possible output of the power supply system. Taking this situation into consideration, a power converter with a smaller rated output is expected to be selected more frequently, so a low output power converter has a higher frequency of discharge operation than a high output power converter. It is expected to be. By connecting a storage device having a larger rated capacity to the low output power converter, the time during which the low output power converter can be discharged can be extended.

[Modification]
The present invention has been described above in detail based on the embodiments. However, the present invention is not limited to the above embodiment. The present invention can be variously modified without departing from the scope of the invention.

  Regardless of whether or not the response speeds differ among the plurality of power converters 30 in the power supply system 1, the response delay compensation is not a necessary process. Accordingly, the power converter information may not include the response speed.

  When comparing the magnitude relationship between two numerical values in the power supply system 1, either of the two criteria of "more than" and "greater than" may be used, and the two criteria of "less than" and "less than" Either of these may be used. The choice of such criteria does not change the technical significance of the process of comparing the magnitude of the two numbers.

  DESCRIPTION OF SYMBOLS 1 ... Power supply system, 10 ... Power generation device, 20 ... Power storage device, 30 ... Power converter, 2 ... Load, 3 ... Contactor, 80 ... Heat pump unit, 40 ... AC bus, 51-55 ... DC bus, 100 ... Supervising controller (Power control device) 101 processor 102 memory 103 communication interface 111 request acquisition unit 112 selection unit 113 instruction unit 121 power converter information 122 selection rule 140 communication Line 210 head local controller 220 local controller P1 power control program P10 main module P11 request acquisition module P12 selection module P13 instruction module

Claims (6)

A request acquisition unit for acquiring a required power indicating a power to be supplied to a load from a power supply system including a plurality of sets of a power storage device and a power converter;
A selection unit which selects at least one power converter to be subjected to discharge operation from the plurality of power converters based on the required power, and sets an output power of each of the at least one power converter;
And an instruction unit for transmitting a discharge instruction to each of the selected at least one power converter,
The rated output is different between at least two of the plurality of power converters,
The selection unit sets the output power of each of the at least one power converter to a limit output or more based on the required power.
Power control unit. The response speed is different between at least two of the plurality of power converters,
The low response power conversion when the selection unit selects two or more power converters including a low response power converter and a high response power converter whose response speed is faster than the low response power converter Adjusting the output power of the high response power converter to compensate for the response delay of the
The power supply control device according to claim 1. The plurality of power converters include at least one low output power converter and a high output power converter having the rated output larger than the at least one low output power converter;
The rated output of the high output power converter is set based on the rated output of the at least one low output power converter and a limiting output ratio common to the plurality of power converters.
The power supply control device according to claim 1. The plurality of power converters include a low output power converter and a high output power converter having the rated output larger than the low output power converter;
The rated capacity of the first storage device connected to the low output power converter is greater than the rated capacity of the second storage device connected to the high output power converter,
The power supply control device according to any one of claims 1 to 3. A power control method executed by a power control device, comprising:
Obtaining a required power indicating a power to be supplied to a load from a power supply system including a plurality of sets of a power storage device and a power converter;
Selecting at least one power converter to be subjected to discharge operation among the plurality of power converters based on the required power, and setting an output power of each of the at least one power converter;
Sending a discharge command to each of the selected at least one power converter;
The rated output is different between at least two of the plurality of power converters,
In the selection step, the output power of each of the at least one power converter is set to a limit output or more based on the required power.
Power control method. Obtaining a required power indicating a power to be supplied to a load from a power supply system including a plurality of sets of a power storage device and a power converter;
Selecting at least one power converter to be subjected to discharge operation among the plurality of power converters based on the required power, and setting an output power of each of the at least one power converter;
Causing the computer to execute an instruction step of transmitting a discharge instruction to each of the selected at least one power converter;
The rated output is different between at least two of the plurality of power converters,
In the selection step, the output power of each of the at least one power converter is set to a limit output or more based on the required power.
Power control program.

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