Power system
The power system addresses the challenge of diverse power sources by using a calculation and modification unit to adjust control commands, enabling flexible power control for each device while maintaining system optimization.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Patents
- Current Assignee / Owner
- DAIHEN CORP
- Filing Date
- 2022-09-20
- Publication Date
- 2026-05-13
AI Technical Summary
Existing power systems struggle to provide flexible power control for diverse distributed power sources such as solar power conditioners, battery power conditioners, and electric vehicle charging stations, as they require different control strategies based on their type.
A power system with a calculation unit that calculates a common control command value and a modification unit that adjusts this value for specific devices to achieve different objectives, allowing normal devices to follow the common command and specific devices to follow the adjusted command, thereby enabling flexible power control for each device while maintaining system control.
The system achieves flexible power control for individual devices while ensuring overall system power control, optimizing power output from solar cells and electric vehicle charging/discharging to match generation and demand effectively.
Smart Images
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Abstract
Description
Technical Field
[0001] The present disclosure relates to a power system.
Background Art
[0002] Power systems that manage a plurality of power devices connected to a power system and control power reception from the power system are becoming widespread. For example, Patent Documents 1 and 2 disclose an example of a power system including a plurality of power devices and a processing device (central management device). The processing device calculates an index (induction command value) for controlling a predetermined adjustment target power to a target power. Each power device dispersedly controls the output power using the induction command value calculated by the processing device. At this time, each power device calculates a target value of the output power based on an optimization problem using the induction command value. Then, the output power is controlled so that the output power becomes the target value. In this way, energy management of the power system is performed.
Prior Art Documents
Patent Documents
[0003]
Patent Document 1
Patent Document 2
Summary of the Invention
Problems to be Solved by the Invention
[0004] Distributed power sources are becoming more diverse. For example, the power system described in Patent Document 2 includes power control devices such as a solar power conditioner, a battery power conditioner, an electric vehicle charging station, and a generator control device. These power control devices have different output characteristics and require different power control depending on the type of distributed power source they are connected to. For example, a solar power conditioner may be required to output power without suppressing the electricity generated by the solar cells as much as possible. Similarly, an electric vehicle charging station may be required to either discharge the electric vehicle as much as possible or charge it as much as possible. In other words, while power control is performed for the entire system, more flexible power control is required for each power control device.
[0005] This disclosure was conceived in view of the above-mentioned problems, and its purpose is to provide a power system that enables more flexible power control of each power control device while performing power control of the entire system. [Means for solving the problem]
[0006] The power system provided by this disclosure comprises a plurality of power control devices that control the output power of a controlled object to which each is connected; a calculation unit that calculates a control command value for the plurality of power control devices; and a modification unit that changes the control command value calculated by the calculation unit to a modified control command value, wherein the control command value calculated by the calculation unit is a value for achieving a first objective of making the power to be adjusted a target power; the plurality of power control devices include at least one specific device that is controlled to achieve a second objective different from the first objective, and normal devices other than the specific device, wherein the modified control command value is a value for achieving the second objective; the normal devices control the output power based on the control command value calculated by the calculation unit; and the specific device controls the output power based on the modified control command value.
[0007] In a preferred embodiment of the power system, the control command value is an induction command value common to two or more of the plurality of power control devices, the calculation unit calculates the induction command value for achieving the first objective, and the modification unit changes the induction command value calculated by the calculation unit to a modified induction command value.
[0008] In a preferred embodiment of the power system, the plurality of power control devices include a plurality of first power control devices belonging to a first group and a plurality of second power control devices belonging to a second group, the induction command value calculated by the calculation unit includes a common first induction command value for the plurality of first power control devices and a common second induction command value for the plurality of second power control devices, the modification unit changes the first induction command value to a modified first induction command value if the first group includes the specified device, and the specified device of the first group controls the output power based on the modified first induction command value.
[0009] In a preferred embodiment of the power system, the modification unit modifies the first induction command value calculated by the calculation unit according to a correction algorithm for achieving the second objective, thereby changing it to the modified first induction command value.
[0010] In a preferred embodiment of the power system, the modification unit outputs a second guidance command value calculated by the calculation unit as the modified first guidance command value, instead of the first guidance command value calculated by the calculation unit.
[0011] In a preferred embodiment of the power system, the plurality of power control devices include a photovoltaic power generation control device that controls the output power of a solar cell as the control target, and the modification unit changes the control command value to the modified control command value with the second objective being to match the output of the photovoltaic power generation control device with the amount of power generated by the solar cell when the photovoltaic power generation control device is the specific device. [Effects of the Invention]
[0012] In the power system of this disclosure, the calculation unit calculates a control command value to achieve the first objective, and the modification unit changes the control command value calculated by the calculation unit to a modified control command value to achieve the second objective. Then, the normal device controls the output power based on the control command value calculated by the calculation unit, and the specific device controls the output power based on the modified control command value changed by the modification unit. As a result, the second objective is achieved by controlling the output power by the specific device, and the first objective is achieved by controlling the output power by the normal device. Therefore, according to the power system of this disclosure, it is possible to control the power of each power control device more flexibly while performing power control of the entire system. [Brief explanation of the drawing]
[0013] [Figure 1] This is a diagram showing the overall configuration of the power system according to the first embodiment. [Figure 2] This is a schematic diagram showing an example of operation of a relay device in a power system according to the first embodiment. [Figure 3] This figure shows the overall configuration of the power system according to the second embodiment. [Figure 4] This is a schematic diagram showing an example of operation of a relay device in a power system according to the second embodiment. [Figure 5] This is a schematic diagram showing another example of operation of a relay device in a power system according to the second embodiment. [Figure 6] This diagram shows the overall configuration of the power system according to the third embodiment. [Figure 7] This is a schematic diagram showing an example of operation of a relay device in a power system according to the third embodiment. [Modes for carrying out the invention]
[0014] Preferred embodiments of the power system of this disclosure are described below with reference to the drawings. In the following description, identical or similar components are denoted by the same reference numerals, and redundant descriptions are omitted. Furthermore, the configurations of the parts in each embodiment and each modification described below are interchangeable to the extent that no technical inconsistencies arise.
[0015] Figure 1 shows the overall configuration of the power system S1 according to the first embodiment. As shown in Figure 1, the power system S1 comprises a processing unit A1, a plurality of power control devices B1, a relay device C1, a detection device D1, and a transformer 91. In Figure 1, the power network is shown with a thick line, and the communication network is shown with a dashed line. In this embodiment, the plurality of power control devices B1 include a plurality of solar power generation control devices 20 and a plurality of EV charge / discharge control devices 30. Unlike the example shown in Figure 1, the number of solar power generation control devices 20 may be one, and the number of EV charge / discharge control devices 30 may be one. EV is an abbreviation for Electric Vehicle. Each of the plurality of solar power generation control devices 20 is connected to a solar cell 29 as a control target. Each of the plurality of EV charge / discharge control devices 30 can be connected to an electric vehicle 39 as a control target. In this disclosure, an electric vehicle 39 means an automobile that can run using an electric motor as a power source, and includes fuel cell vehicles or automobiles equipped with an internal combustion engine (e.g., plug-in hybrid vehicles). The electric motor is powered by electricity stored in the battery installed in the electric vehicle 39.
[0016] Power system S1 is connected to connection point T and interconnected to power grid K. Power system S1 is capable of receiving power from power grid K. In this embodiment, power system S1 is not capable of transmitting power to power grid K (i.e., reverse power flow), but it may be capable of transmitting power to power grid K (i.e., reverse power flow). In this disclosure, when power is output from power grid K to power system S1, the connection point power is assumed to be a negative value. Connection point power refers to the power at the connection point T between power system S1 and power grid K. Power system S1 is capable of supplying power from power grid K and power supplied from controlled objects connected to each power control device B1 to power load L connected to connection point T. Note that power load L is not required to be connected to power system S1.
[0017] The power system S1 performs power control so as to achieve the first target. The first target is to set the power to be adjusted to the target power. In the present embodiment, the connection point power is targeted as the power to be adjusted. That is, the power system S1 performs power control so that the connection point power as the power to be adjusted becomes the target power. The target power is the target value (adjustment target value) of the power to be adjusted, and in the present embodiment, it is the target value of the connection point power. Further, the power system S1 performs power control so as to achieve the second target for at least one or more power control devices B1. Hereinafter, the power control device B1 controlled so as to achieve the second target is referred to as "specific device B2", and the power control device B1 other than the specific device B2 is referred to as "normal device B3". As the second target, for example, there is a control target of making the total output power of a plurality of solar power generation control devices 20 coincide with the total power generation amount of a plurality of solar cells 29. In this case, each solar power generation control device 20 is controlled as the specific device B2, and each EV charging / discharging control device 30 is controlled as the normal device B3. Different from this example, any one of the plurality of solar power generation control devices 20 may be used as the specific device B2, and the output power of the solar power generation control device 20 may be made to coincide with the power generation amount of the solar cell 29 to which the solar power generation control device 20 is connected. Another example of the second target is a control target of making each electric vehicle 39 discharge as little as possible or charge as little as possible. In this case, each EV charging / discharging control device 30 is controlled as the specific device B2, and each solar power generation control device 20 is controlled as the normal device B3. Different from this example, any one of the plurality of EV charging / discharging control devices 30 may be used as the specific device B2, and the electric vehicle 39 connected to the EV charging / discharging control device 30 may be made to discharge as little as possible or charge as little as possible.
[0018] In the power control of the power system S1, the processing unit A1 calculates a control command value to control the connection point power (power to be adjusted) to a target power (adjustment target value). In this embodiment, the control command value calculated by the processing unit A1 is an induction command value common to multiple power control devices B1. The processing unit A1 transmits the calculated induction command value (control command value) to the relay device C1. The relay device C1 receives the induction command value (control command value) from the processing unit A1 and changes the received induction command value (control command value) to a modified induction command value (modified control command value). Then, it transmits the modified induction command value (modified control command value) to the specific device B2 and transmits the original induction command value (original control command value) to the normal device B3. The specific device B2 receives the modified induction command value (modified control command value) from the relay device C1 and controls the output power of the controlled object based on the received modified induction command value (modified control command value). Normally, device B3 receives the pre-change induction command value from relay device C1 and controls the output power of the controlled object based on the received pre-change induction command value (pre-change control command value). Through the above process, power system S1 controls specific device B2 to achieve the second objective while controlling the connection point power to the target power. Therefore, power system S1 performs power control to achieve the first objective and power control to achieve the second objective in parallel by having multiple power control devices B1 distribute the output power control. In an example different from the example described above, relay device C1 may transmit the pre-change induction command value (pre-change control command value) and the changed induction command value (changed control command value) to each power control device B1 in a single transmission without distinguishing between specific device B2 and normal device B3. In this case, specific device B2 does not receive the pre-change induction command value (pre-change control command value), or even if it receives it, it does not use the pre-change induction command value (pre-change control command value). Normally, device B3 does not receive the modified guidance command value (modified control command value), or even if it receives it, it does not use the modified guidance command value (modified control command value). In an example different from the example described above, processing device A1 may transmit the calculated guidance command value to relay device C1 and also transmit it collectively to each power control device B1.In this case, the normal device B3 may control the output power of the controlled object based on the pre-change guidance command value (pre-change control command value) directly received from the processing device A1, rather than the pre-change guidance command value (control command value) received from the relay device C1.
[0019] The transformer 91 is composed of, for example, a three-phase three-winding transformer. The transformer 91 has a first winding 911, a second winding 912, and a third winding 913. The first winding 911 is connected to the connection point T. Each solar power generation control device 20 is connected to the second winding 912. Each EV charging / discharging control device 30 is connected to the third winding 913. Predetermined winding capacities are set for the first winding 911, the second winding 912, and the third winding 913 respectively. The winding capacities of the first winding 911, the second winding 912, and the third winding 913 are not limited in any way. The transformer 91 may be composed of two two-winding transformers, namely, a two-winding transformer connected between the connection point T and each solar power generation control device 20, and a two-winding transformer connected between the connection point T and each EV charging / discharging control device 30. However, by using a three-winding transformer, space saving and weight reduction can be achieved compared to the case of using two two-winding transformers.
[0020] The detection device D1 detects the connection point power. The detection device D1 includes a detection unit 71 and a communication processing unit 72. The detection unit 71 is connected to the connection point T between the power system S1 and the power grid K and detects the connection point power. The detection unit 71 is, for example, a power transducer. The detection unit 71 can communicate with the communication processing unit 72 and outputs the detected value of the connection point power to the communication processing unit 72. The communication processing unit 72 includes an AD converter that converts the detected value of the connection point power (analog value) input from the detection unit 71 into a digital value, and transmits the detected value of the connection point power (digital value) after conversion to the processing device A1. Various protection devices (such as overcurrent relays, overvoltage relays, underpower relays, and reverse power relays, etc.) for connecting the power system S1 to the power grid K are further installed in the detection device D1 as required.
[0021] Processing unit A1 includes a calculation unit 11 and a communication processing unit 12. The calculation unit 11 and the communication processing unit 12 communicate bidirectionally. The calculation unit 11 and the communication processing unit 12 are not limited to being composed of separate modules, but may be composed of a single module.
[0022] The communication processing unit 12 communicates with each of the multiple power control devices B1, relay device C1, and detection device D1. The communication processing unit 12 receives the detected output power of each power control device B1 from the respective power control device B1. The communication processing unit 12 transmits the calculated induction command value to the relay device C1. The communication processing unit 12 receives the detected connection point power from the detection device D1.
[0023] The calculation unit 11 calculates an induction command value to achieve the above-mentioned first objective. In this embodiment, the calculation unit 11 monitors the connection point power and calculates an induction command value to control the connection point power to the target power (adjustment target value). As described above, the induction command value calculated by the calculation unit 11 is common to the multiple power control devices B1. The connection point power may be a detected value detected by the detection device D1, or an estimated value calculated from the output power values obtained by communication from each power control device B1. The target power may be a value set in a management computer (not shown), or a value preset according to a predetermined control mode. The predetermined control mode is, for example, the same as that described in Patent Document 1. For example, the induction command value calculated by the calculation unit 11 is positive if the connection point power is greater than the target power, and negative if the connection point power is less than the target power. The calculation unit 11 calculates the induction command value by solving a predetermined state equation (simultaneous differential equations). This predetermined state equation is, for example, the same as that described in Patent Document 2. In other words, the method for calculating the guidance command value in the calculation unit 11 is the same as the calculation method described in Patent Document 2. The calculation unit 11 transmits the calculated guidance command value to the relay device C1 via the communication processing unit 12.
[0024] The relay device C1 has a modification unit 61 and a communication processing unit 62. The modification unit 61 and the communication processing unit 62 communicate bidirectionally. The modification unit 61 and the communication processing unit 62 are not limited to being composed of separate modules, but may be composed of a single module.
[0025] The communication processing unit 62 relays communication between the processing unit A1 and each of the multiple power control devices B1 and the modification unit 61. The communication processing unit 62 receives the induction command value from the processing unit A1 and inputs the received induction command value to the modification unit 61. The communication processing unit 62 also transmits the modified induction command value input from the modification unit 61 to the specific device B2 and transmits the original induction command value (the induction command value calculated by the calculation unit 11) input from the modification unit 61 to the normal device B3.
[0026] The modification unit 61 changes the guidance command value (calculated by the calculation unit 11) input from the communication processing unit 62 to a modified guidance command value for achieving the second objective. In this embodiment, the modification unit 61 corrects the guidance command value calculated by the calculation unit 11 according to a predetermined correction algorithm, thereby changing the guidance command value calculated by the calculation unit 11 to a modified guidance command value. The correction algorithm corrects the total output power of multiple solar power PCS 21 (hereinafter referred to as "total PCS output") to match the total power generation of multiple solar cells 29 (hereinafter referred to as "total power generation"), in accordance with the second objective. For example, if the total PCS output is greater than the total power generation, the guidance command value modified by the modification unit 61 will be greater than the guidance command value calculated by the calculation unit 11, and if the total PCS output power is less than the total power generation, the guidance command value modified by the modification unit 61 will be smaller than the guidance command value calculated by the calculation unit 11.
[0027] Each of the multiple power control devices B1 includes, as described above, multiple photovoltaic power generation control devices 20 to which solar cells 29 are connected as controlled devices, and multiple EV charge / discharge control devices 30 to which electric vehicles 39 are connected as controlled devices.
[0028] Each of the multiple solar power generation control devices 20 controls the power generation by the solar cells 29. Each of the multiple solar power generation control devices 20 includes a solar power conditioner 21 and a communication processing unit 22. In this disclosure, a power conditioner is referred to as "PCS". The solar PCS 21 and the communication processing unit 22 described below are common to each solar power generation control device 20 unless otherwise specified. The solar PCS 21 and the communication processing unit 22 communicate bidirectionally. The solar PCS 21 and the communication processing unit 22 are not limited to being composed of separate modules, but may be composed of a single module.
[0029] The communication processing unit 22 relays communication between the processing unit A1 and the relay device C1, and the solar power PCS 21. If the solar power generation control device 20, including the communication processing unit 22, is a specific device B2, the communication processing unit 22 receives the modified guidance command value from the relay device C1 and calculates the output target value of the solar power PCS 21 based on the received modified guidance command value. If the solar power generation control device 20, including the communication processing unit 22, is a normal device B3, the communication processing unit 22 receives the guidance command value before modification from the relay device C1 and calculates the output target value of the solar power PCS 21 based on the received guidance command value before modification. The communication processing unit 22 uses the received (before or after modification) guidance command value to calculate the output target value according to a predetermined calculation formula and constraints. This calculation formula and constraints are the same as those described in, for example, Patent Document 2. In other words, the method used by the communication processing unit 22 to calculate the output target value of the solar power PCS 21 is the same as the calculation method described in Patent Document 2. The communication processing unit 22 transmits the calculated output target value to the solar power PCS 21.
[0030] The solar power PCS 21 is connected to a solar cell 29 and converts the power generated by the solar cell 29 (e.g., DC power) into power suitable for grid connection (e.g., AC power) and outputs it. In Figure 1, one solar cell 29 is connected to the solar power PCS 21, but multiple solar cells 29 may be connected. The solar power PCS 21 is connected to the second winding 912 of the transformer 91. The rated output of each solar power PCS 21 is set so that the sum of the rated outputs of each solar power PCS 21 connected to the second winding 912 is less than or equal to the winding capacity of the second winding 912. The solar power PCS 21 outputs the power generated by the solar cell 29 to the transformer 91. The solar power PCS 21 controls the output power of the controlled object (solar cell 29) by controlling the amount of power generated by the solar cell 29 based on the output target value received from the communication processing unit 22. Specifically, the solar power PCS 21 controls the power so that the output power of the solar cell 29 becomes the output target value.
[0031] The solar power PCS 21 detects the output power value and transmits it to the communication processing unit 22. The communication processing unit 22 receives the detected output power value from the solar power PCS 21 and transmits it to the processing unit A1 and the relay device C1. The solar power PCS 21 also obtains information on the amount of power generated by the solar cell 29 from the solar cell 29 and transmits it to the communication processing unit 22. The communication processing unit 22 receives the information on the amount of power generated by the solar cell 29 from the solar power PCS 21 and transmits it to the relay device C1. Note that the information on the amount of power generated by the solar cell 29 may be transmitted directly from the solar cell 29 to the relay device C1 without going through the solar power generation control device 20.
[0032] Each of the multiple EV charge / discharge control devices 30 controls the charging and discharging of an electric vehicle 39. Each of the multiple EV charge / discharge control devices 30 includes an EV stand 31 and a communication processing unit 32. The EV stand 31 and communication processing unit 32 described below are common to each EV charge / discharge control device 30 unless otherwise specified. The EV stand 31 and the communication processing unit 32 communicate bidirectionally. The EV stand 31 and the communication processing unit 32 are not limited to being composed of separate modules, but may be composed of a single module.
[0033] The communication processing unit 32 relays communication between the processing unit A1 and the relay device C1, and the EV stand 31. If the EV charge / discharge control device 30, which includes the communication processing unit 32, is a specific device B2, the communication processing unit 32 receives the modified induction command value from the relay device C1 and calculates the output target value of the EV stand 31 based on the received modified induction command value. If the EV charge / discharge control device 30, which includes the communication processing unit 32, is a normal device B3, the communication processing unit 32 receives the original induction command value from the relay device C1 and calculates the output target value of the EV stand 31 based on the received original induction command value. The communication processing unit 32 uses the received (original or modified) induction command value to calculate the output target value according to a predetermined calculation formula and constraints. This calculation formula and constraints are the same as those described in, for example, Patent Document 2. As described in Patent Document 2, the calculation formulas set in the communication processing unit 22 and the communication processing unit 32 are the same, but the constraints set in them are different. In other words, the method used by the communication processing unit 32 to calculate the target output value for the EV stand 31 is the same as the calculation method described in Patent Document 2. The communication processing unit 32 transmits the calculated target output value to the EV stand 31.
[0034] EV station 31 is connected to an electric vehicle 39 and performs charging and discharging of the electric vehicle 39 (specifically, charging and discharging of the battery installed in the electric vehicle 39). In Figure 1, one electric vehicle 39 is connected to one EV station 31, but multiple electric vehicles 39 may be connected. EV station 31 is connected to the third winding 913 of transformer 91. The rated output of each EV station 31 is set such that the sum of the rated outputs of all EV stations 31 connected to the third winding 913 is less than or equal to the winding capacity of the third winding 913. EV station 31 charges the electric vehicle 39 by supplying power input from transformer 91 to each electric vehicle 39. EV station 31 also discharges the electric vehicle 39 by outputting the power stored in each electric vehicle 39 to transformer 91. EV station 31 controls the amount of charge and discharge of the electric vehicle 39 based on the output target value received from communication processing unit 32. As a result, the EV station 31 controls the output power of the controlled object (electric vehicle 39). Specifically, the EV station 31 controls the power so that the output power of the electric vehicle 39 reaches the output target value. When the received output target value is a positive value, the EV station 31 discharges the electric vehicle 39. On the other hand, when the received output target value is a negative value, the EV station 31 charges the electric vehicle 39.
[0035] The EV station 31 detects the output power value to the electric vehicle 39 and transmits it to the communication processing unit 32. The communication processing unit 32 receives the detected output power value from the EV station 31 and transmits it to the processing unit A1 and the relay device C1. The EV station 31 also obtains the charge level (SoC) of the connected electric vehicle 39. The EV station 31 transmits the charge level of the electric vehicle 39 to the communication processing unit 32. The information on the charge level of the electric vehicle 39 is used by the communication processing unit 32 to calculate the output target value.
[0036] Figure 2 is a schematic diagram showing an example of the operation of a relay device C1 in a power system S1. In Figure 2, of the two power control devices B1, one is a specific device B2 and the other is a normal device B3.
[0037] In the example shown in Figure 2, the processing unit A1 transmits the induction command value Pr1 calculated by the calculation unit 11 to the relay device C1. The relay device C1 changes the received induction command value Pr1 to the modified induction command value Pr2 according to the correction algorithm X for achieving the second objective. Then, the relay device C1 transmits the modified induction command value Pr2 to the specific device B2 and the original induction command value Pr1 to the normal device B3. The specific device B2 receives the modified induction command value Pr2 and controls the output power of the controlled object connected to itself based on the received modified induction command value Pr2. As a result, the power system S1 achieves the second objective through output power control by the specific device B2. The normal device B3 also receives the original induction command value Pr1 and controls the output power of the controlled object connected to itself based on the received original induction command value Pr1. As a result, the power system S1 achieves the first objective through output power control by the normal device B3 (the connection point power becomes the target power).
[0038] With the power system S1 configured as described above, the normal device B3 controls the output power based on the induction command value calculated by the calculation unit 11, thus achieving the first objective of making the connection point power the target power through the control of the output power by the normal device B3. Furthermore, the specific device B2 controls the output power based on the induction command value (modified induction command value) changed by the modification unit 61, thus achieving the second objective through the control of the output power by the specific device B2. In other words, the power system S1 performs power control to achieve the first objective set for the entire system while also achieving the second objective set for at least one or more power control devices B1. Therefore, the power system S1 can perform power control for the entire system while also performing power control for each power control device B1 more flexibly. In addition, it is possible to achieve the second objective, so for example, if the second objective is set to match the sum of the output powers of multiple photovoltaic power generation control devices 20 with the sum of the power generation amounts of multiple solar cells 29, it becomes possible to make maximum use of the power generated by multiple solar cells 29.
[0039] Figure 3 shows the overall configuration of the power system S2 according to the second embodiment. As shown in Figure 3, the power system S2 manages multiple power control devices B1 by dividing them into multiple groups. In the example shown in Figure 3, the power system S2 includes multiple first power control devices B11 belonging to the first group G1 and multiple second power control devices B12 belonging to the second group G2. The multiple first power control devices B11 are connected to the first transformer 91A, and the multiple second power control devices B12 are connected to the second transformer 91B. The first transformer 91A and the second transformer 91B are each configured similarly to the transformer 91. The power system S2 is capable of performing power control to achieve a first objective for the entire system while also achieving a second objective for each of the multiple groups.
[0040] The power system S2 includes, for example, a plurality of first power control devices B11 which include a photovoltaic power generation control device 20 and an EV charge / discharge control device 30, and a plurality of second power control devices B12 which include a photovoltaic power generation control device 20 and an EV charge / discharge control device 30. In Figure 3, one of the plurality of photovoltaic power generation control devices 20 and one of the plurality of EV charge / discharge control devices 30 are shown in each of the first group G1 and the second group G2. In a configuration different from this example, all of the plurality of first power control devices B11 may be photovoltaic power generation control devices 20, and all of the plurality of second power control devices B12 may be EV charge / discharge control devices 30.
[0041] In the power system S2, the processing device A1 (calculation unit 11) calculates a first induction command value for a plurality of first power control devices B11 (first group G1) and a second induction command value for a plurality of second power control devices B12 (second group G2) so that the connection point power becomes the target power. The first induction command value is a value common to the plurality of first power control devices B11, and the second induction command value is a value common to the plurality of second power control devices B12. The first induction command value and the second induction command value may be the same value or different values. For example, assume a case where the total output of each first power control device B11 belonging to the first group G1 is power-controlled to a target power P1 [W] (P1 < P0) and the total output of each second power control device B12 belonging to the second group G2 is power-controlled to a target power P2 [W] (P2 = P0 - P1) so that the connection point power as the first target becomes the target power P0 [W]. In this case, if the two target powers P1 and P2 are the same (P1 = P2 = P0 / 2), the first induction command value and the second induction command value are the same, and if the two target powers P1 and P2 are different (P1 ≠ P2), the first induction command value and the second induction command value are different. Note that the example where the first induction command value and the second induction command value are different is not limited to the above example.
[0042] The relay device C1 of the power system S2 receives the first guidance command value and the second guidance command value from the processing unit A1. When the relay device C1 receives the first guidance command value, if the first group G1 includes a specific device B2, it changes the received first guidance command value to a modified first guidance command value. Then, the relay device C1 transmits the modified first guidance command value to the specific device B2 of the first group G1, and transmits the original first guidance command value to the normal device B3 of the first group G1. If the first group G1 does not include a specific device B2, the relay device C1 transmits the first guidance command value received from the processing unit A1 to each first power control device B11 without modification. Note that which of the multiple first power control devices B11 in the first group G1 is the specific device B2 and which is the normal device B3 is appropriately selected according to the second objective set for the first group G1. Furthermore, when relay device C1 receives the second guidance command value, if the second group G2 includes specific device B2, it changes the received second guidance command value to the modified second guidance command value. Then, relay device C1 transmits the modified second guidance command value to specific device B2 in the second group G2, and transmits the original second guidance command value to the normal device B3 in the second group G2. If the second group G2 does not include specific device B2, relay device C1 transmits the second guidance command value received from processing device A1 to each second power control device B12 without modification. Note that which of the multiple second power control devices B12 in the second group G2 is specific device B2 and which is normal device B3 is appropriately selected according to the second objective set for the second group G2.
[0043] Of the multiple first power control devices B11, the specific device B2 receives the modified first induction command value from the relay device C1 and controls the output power of the controlled object based on the modified first induction command value. On the other hand, the normal device B3 receives the original first induction command value from the relay device C1 and controls the output power of the controlled object based on the original first induction command value. Similarly, of the multiple second power control devices B12, the specific device B2 receives the modified second induction command value from the relay device C1 and controls the output power of the controlled object based on the modified second induction command value. On the other hand, the normal device B3 receives the original second induction command value from the relay device C1 and controls the output power of the controlled object based on the original second induction command value.
[0044] Figure 4 is a schematic diagram showing an example of the operation of the relay device C1 in the power system S2. In Figure 4, of the two first power control devices B11 belonging to the first group G1, one is a specific device B2 and the other is a normal device B3. Also, of the two second power control devices B12 belonging to the second group G2, one is a specific device B2 and the other is a normal device B3.
[0045] In the example shown in Figure 4, the first guidance command value Pr11 and the second guidance command value Pr21 calculated by the calculation unit 11 are transmitted from the processing unit A1 to the relay device C1. The relay device C1 changes the received first guidance command value Pr11 to the modified first guidance command value Pr12 according to the correction algorithm X for achieving the second target in the first group G1. Then, the relay device C1 transmits the modified first guidance command value Pr12 to the specific device B2 of the first group G1 and transmits the original first guidance command value Pr11 to the normal device B3 of the first group G1. As a result, in the first group G1, output control is performed by the specific device B2 to achieve the second target of the first group G1, and output control is performed by the normal device B3 to achieve the first target. Similarly, the relay device C1 changes the received second guidance command value Pr21 to the modified second guidance command value Pr22 according to the correction algorithm Y for achieving the second target in the second group G2. The correction algorithm Y may be the same as or different from the correction algorithm X described above. Then, the relay device C1 transmits the changed second guidance command value Pr22 to the specific device B2 of the second group G2, and transmits the pre-change second guidance command value Pr21 to the normal device B3 of the second group G2. As a result, in the second group G2, the specific device B2 controls the output to achieve the second objective of the second group G2, and the normal device B3 controls the output to achieve the first objective.
[0046] In the power system S2 configured as described above, similar to the power system S1, the normal device B3 controls the output power based on the induction command value (first induction command value or second induction command value) calculated by the calculation unit 11, and the specific device B2 controls the output power based on the induction command value (modified first induction command value or modified second induction command value) modified by the modification unit 61. Therefore, in the power system S2, similar to the power system S1, it is possible to control the power of each power control device B1 (first power control device B11 and second power control device B12) more flexibly while performing power control of the entire system. Furthermore, in the power system S2, it is possible to set a second target for each of the multiple groups, so it is possible to control the power of each power control device B1 even more flexibly.
[0047] In the second embodiment, the operation of the relay device C1 is not limited to the example shown in Figure 4, but may be as shown in Figure 5, for example, depending on the setting of the second objective. In each of the modified examples shown in Figure 5, both of the two first power control devices B11 belonging to the first group G1 are specific devices B2, and both of the two second power control devices B12 belonging to the second group G2 are normal devices B3.
[0048] In the example shown in Figure 5(a), the relay device C1 modifies the first induction command value Pr11 to the modified first induction command value Pr12 using correction algorithms X and Y for the two first power control devices B11, each of which is a specific device B2. Then, it transmits the modified first induction command value Pr12 to each first power control device B11. On the other hand, the relay device C1 does not change the second induction command value Pr21 to the two second power control devices B12, each of which is a normal device B3, and transmits the second induction command value Pr21 before the change. Note that the example shown in Figure 5(a) is an example in which the induction command values (first induction command value and second induction command value) are changed using correction algorithms X and Y, similar to the example shown in Figure 4.
[0049] In the example shown in Figure 5(b), the relay device C1 transmits the second induction command value Pr21 calculated by the processing unit A1 as the modified first induction command value Pr12 to each of the two first power control devices B11, each of which is a specific device B2. On the other hand, the relay device C1 transmits the original second induction command value Pr21 to the two second power control devices B12, each of which is a normal device B3, without changing the second induction command value Pr21. In the example shown in Figure 5(b), the induction command value is changed to that of another group, rather than being changed by correction algorithms X and Y.
[0050] In the example shown in Figure 5(c), the relay device C1 modifies (corrects) the second induction command value Pr21 calculated by the processing unit A1 using correction algorithms X and Y, and then transmits it to each of the two first power control devices B11, each of which is a specific device B2, as the modified first induction command value Pr12. On the other hand, the relay device C1 transmits the second induction command value Pr21 to the two second power control devices B12, each of which is a normal device B3, without modifying it. The example shown in Figure 5(c) is an example of operation that combines both the modification to the induction command value of the other group and the modification by correction algorithms X and Y.
[0051] Figure 6 shows the overall configuration of the power system S3 according to the third embodiment. In power system S3, the installation locations of the multiple first power control devices B11 belonging to the first group G1 and the installation locations of the multiple second power control devices B12 belonging to the second group G2 are separated. For this reason, a relay device C1 is provided for each of the first group G1 and the second group G2. For ease of understanding, the relay device C1 for the first group G1 is referred to as the first relay device C11, and the relay device C1 for the second group G2 is referred to as the second relay device C12. In power system S3, as in power system S2, each of the multiple first power control devices B11 and the multiple second power control devices B12 includes multiple photovoltaic power generation control devices 20 and multiple EV charge / discharge control devices 30. However, in Figure 6, one of the multiple photovoltaic power generation control devices 20 and one of the multiple EV charge / discharge control devices 30 are shown for each of the first group G1 and the second group G2.
[0052] In power system S3, processing unit A1 calculates a first induction command value and a second induction command value such that the sum of the detected value (connection point power) from the detection device D1 installed for the first group G1 and the detected value (connection point power) from the detection device D1 installed for the second group G2 equals the target power. Then, it transmits the calculated first induction command value to the first relay device C11 and the calculated second induction command value to the second relay device C12. The first and second induction command values are the same as those described in power system S2.
[0053] If the first relay device C11 includes a specific device B2 in the first group G1, i.e., multiple first power control devices B11, it changes the first induction command value to the modified first induction command value. Then, the first relay device C11 transmits the modified first induction command value to the specific device B2 among the multiple first power control devices B11, and transmits the original first induction command value to the normal device B3 among the multiple first power control devices B11. If the first group G1, i.e., multiple first power control devices B11, does not include a specific device B2, the first relay device C11 transmits the first induction command value received from the processing device A1 to each first power control device B11 without changing the first induction command value.
[0054] Similarly, if the second relay device C12 includes a specific device B2 in the second group G2, i.e., multiple second power control devices B12, it changes the second induction command value to the modified second induction command value. Then, the second relay device C12 transmits the modified second induction command value to the specific device B2 among the multiple second power control devices B12, and transmits the original second induction command value to the normal device B3 among the multiple second power control devices B12. If the second group G2, i.e., multiple second power control devices B12, does not include a specific device B2, the second relay device C12 transmits the second induction command value received from the processing device A1 to each second power control device B12 without changing the second induction command value.
[0055] Figure 7 is a schematic diagram showing an example of the operation of relay devices C1 (first relay device C11 and second relay device C12) in power system S3. In Figure 7, of the two first power control devices B11 belonging to the first group G1, one is a specific device B2 and the other is a normal device B3. Also, of the two second power control devices B12 belonging to the second group G2, one is a specific device B2 and the other is a normal device B3.
[0056] In the example shown in Figure 7, the first guidance command value Pr11 is transmitted from the processing unit A1 to the first relay unit C11, and the second guidance command value Pr21 is transmitted from the processing unit A1 to the second relay unit C12. The first relay unit C11 changes the received first guidance command value Pr11 to the modified first guidance command value Pr12 according to the correction algorithm X for achieving the second objective in the first group G1. Then, the first relay unit C11 transmits the modified first guidance command value Pr12 to the specific device B2 of the first group G1, and transmits the original first guidance command value Pr11 to the normal device B3 of the first group G1. As a result, in the first group G1, the specific device B2 performs output control to achieve the second objective of the first group G1, and the normal device B3 performs output control to achieve the first objective. Similarly, the second relay device C12 changes the received second guidance command value Pr21 to a modified second guidance command value Pr22 according to the correction algorithm Y for achieving the second objective in the second group G2. Then, the second relay device C12 transmits the modified second guidance command value Pr22 to the specific device B2 of the second group G2 and transmits the original second guidance command value Pr21 to the normal device B3 of the second group G2. As a result, in the second group G2, the specific device B2 performs output control to achieve the second objective of the second group G2, and the normal device B3 performs output control to achieve the first objective.
[0057] In the power system S3 configured as described above, similar to the power system S2, the normal device B3 controls the output power based on the induction command value (first induction command value or second induction command value) calculated by the calculation unit 11, and the specific device B2 controls the output power based on the induction command value (modified first induction command value or modified second induction command value) modified by the modification unit 61. Therefore, in the power system S3, similar to the power system S2, it is possible to control the power of each power control device B1 (first power control device B11 and second power control device B12) more flexibly while performing power control of the entire system. Furthermore, in the power system S3, similar to the power system S2, it is possible to set a second target for each of the multiple groups, so that the power control of each power control device B1 can be controlled even more flexibly.
[0058] In the second and third embodiments, as a second objective for the first group G1, power control may be performed so that the sum of the output powers of the multiple first power control devices B11 of the first group G1 does not exceed the capacity of the first transformer 91A provided for the first group G1. For example, if the sum of the output powers of the multiple first power control devices B11 exceeds the capacity of the first transformer 91A, the modification unit 61 of the relay device C1 (or first relay device C11) changes the first induction command value calculated by the calculation unit 11 to a value such that the sum of the output powers of the multiple first power control devices B11 does not exceed the capacity of the first transformer 91A. In this case, all of the multiple first power control devices B11 are controlled as specific devices B2. Similarly, as a second objective for the second group G2, power control may be performed so that the sum of the output powers of the multiple second power control devices B12 of the second group G2 does not exceed the capacity of the second transformer 91B provided for the second group G2. For example, if the sum of the output power of each second power control device B12 exceeds the capacity of the second transformer 91B, the modification unit 61 of the relay device C1 (or second relay device C12) changes the second induction command value calculated by the calculation unit 11 to a value such that the sum of the output power of each second power control device B12 does not exceed the capacity of the second transformer 91B. In this case, all of the multiple second power control devices B12 are controlled as specific devices B2.
[0059] In the first to third embodiments, an example was shown in which the modification unit 61 is provided in the relay device C1, but the modification unit 61 may also be provided in the processing device A1. In this case, there is no relay device C1, and the calculation of the guidance command value and the modification of the guidance command value are performed in a single device.
[0060] In the first to third embodiments, examples were shown in which a plurality of power control devices B1, a plurality of first power control devices B11, and a plurality of second power control devices B12 each included a solar power generation control device 20 and an EV charge / discharge control device 30. However, in addition to or instead of these, one or more of a battery charge / discharge control device and a generator control device may be included. The battery charge / discharge control device is connected to a battery as the control target and controls the charging and discharging of the battery. The control method of the battery charge / discharge control device is similar to the control method of the EV charge / discharge control device 30. The generator control device is connected to a generator (e.g., a diesel generator, a hydroelectric generator, a wind turbine, etc.) as the control target and controls the power generation by the generator. The control method of the generator control device is similar to the control method of the solar power generation control device 20.
[0061] In the first to third embodiments, the processing unit A1 calculates induction command values (first induction command value and second induction command value) as control command values by solving a state equation, similar to the power system described in Patent Document 2, and each power control device B1 (each first power control device B11 and each second power control device B12) performs distributed output control. In contrast to this configuration, the processing unit A1 (calculation unit 11) may calculate the output target values (first output target value and second output target value) of each power control device B1 to achieve the system objective, and the relay device C1 (modification unit 61) may change the output target values (first output target value and second output target value) of each power control device B1 to achieve the operational objective. In other words, the control command value in this modified example is not an index for the multiple power control devices B1 (multiple first power control devices B11 and multiple second power control devices B12) to calculate the output target in a distributed manner, but may be the output target value of each of the multiple power control devices B1 (each first output target value of each of the multiple first power control devices B11 and each second output target value of each of the multiple second power control devices B12). In this case, each power control device B1 (each first power control device B11 and each second power control device B12) controls its power so that the output power of its own device becomes the output target value (first output target value and second output target value) received from the processing device A1 or the relay device C1.
[0062] The power system relating to this disclosure is not limited to the embodiments described above. The specific configuration of each part of the power system relating to this disclosure can be modified in various ways. [Explanation of Symbols]
[0063] S1-S3: Power system, 11: Calculation unit, 20: Photovoltaic power generation control device, 29: Solar cell, 30: EV charge / discharge control device, 39: Electric vehicle, 61: Modification unit, A1: Processing unit, B1: Power control device, B11: First power control device, B12: Second power control device, B2: Specific device, B3: Normal device, C1: Relay device, G1: First group, G2: Second group
Claims
1. Multiple power control devices that control the output power of the controlled object to which each is connected, A calculation unit that calculates control command values for the plurality of power control devices, A modification unit that changes the control command value calculated by the calculation unit to the modified control command value, Equipped with, The control command value calculated by the calculation unit is a value that achieves the first objective of making the power to be adjusted into the target power. The plurality of power control devices include at least one specific device controlled to achieve a second objective different from the first objective, and a normal device other than the specific device. The modified control command value is a value that is used to achieve the second objective. The conventional device controls the output power based on the control command value calculated by the calculation unit. The specified device is a power system that controls output power based on the modified control command value.
2. The control command value is an induction command value common to two or more of the plurality of power control devices. The calculation unit calculates the guidance command value for achieving the first objective, The power system according to claim 1, wherein the modification unit changes the induction command value calculated by the calculation unit to the modified induction command value.
3. The plurality of power control devices include a plurality of first power control devices belonging to a first group and a plurality of second power control devices belonging to a second group, The induction command value calculated by the calculation unit includes a common first induction command value for the plurality of first power control devices and a common second induction command value for the plurality of second power control devices. The modification unit, when the first group includes the specified device, modifies the first induction command value and then modifies it back to the first induction command value. The power system according to claim 2, wherein the specified device of the first group controls the output power based on the modified first induction command value.
4. The power system according to claim 3, wherein the modification unit modifies the first induction command value calculated by the calculation unit in accordance with a correction algorithm for achieving the second objective, thereby changing it to the modified first induction command value.
5. The power system according to claim 3, wherein the modification unit outputs a second guidance command value calculated by the calculation unit as the modified first guidance command value, instead of the first guidance command value calculated by the calculation unit.
6. The plurality of power control devices include a photovoltaic power generation control device that controls the output power of the solar cell as the control target, The power system according to any one of claims 1 to 5, wherein the modification part, when the solar power generation control device is the specified device, changes the control command value to the modified control command value with the second objective of matching the output of the solar power generation control device with the amount of power generated by the solar cell.