Power system

Abstract

To provide a power system capable of continuing an appropriate energy management, even if a state change of a power apparatus occurs.SOLUTION: A power system S1 for controlling junction point power at a junction point K with a power system D, includes a processing device A1 including a first calculation unit 21 for calculating an induction command value for setting the junction point power as target power, and a plurality of power control devices B1 to which a corresponding power apparatus Y among a plurality of power apparatuses is connected respectively. Each of the plurality of power control devices B1 controls output power of the corresponding power apparatus Y based on a common induction command value inputted from the processing device A1. The first calculation unit 21 uses a whole power control width when calculating the induction command value. The whole power control width is a total value of individual power control widths that is maximum power which can be outputted of each of the plurality of power apparatuses Y. The processing device A1 further includes a first update unit 222 for updating the whole power control width.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a power system.

Background Art

[0002] Power systems that manage a plurality of power devices (distributed power sources) connected to a power grid and control power reception from the power grid are becoming increasingly popular. For example, Patent Document 1 discloses an example of a power system including a processing device and a plurality of power control devices. The processing device calculates an induction command value for controlling the connection point power to a target power. The connection point power is the power at the connection point between the power system and the power grid. Each power control device is connected to a corresponding power device (distributed power source). Each power control device controls the output power of the connected power device. Examples of power devices include solar cells, storage batteries, and electric vehicles. Each power control device dispersedly controls the output power using the induction command value calculated by the processing device. At this time, each power control 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 such a power system, compared with a configuration in which the processing device collectively controls a plurality of power control devices, even if the number of power devices increases, the processing load of the processing device does not increase significantly.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the power system described in Patent Document 1, the processing unit has a set value for calculating the induction command value. This set value is pre-set when the power system starts operation. Therefore, in conventional power systems, if a change in the state of power equipment occurs, it may affect the energy management performed by the power system, making it impossible to perform optimal energy management. Here, a change in the state of power equipment refers to deterioration and failure of power equipment, and the addition and removal of distributed power sources.

[0005] This disclosure was conceived in view of the above circumstances, and its purpose is to provide a power system that can continue to perform appropriate energy management even when changes in the state of power equipment occur. [Means for solving the problem]

[0006] The power system of the present disclosure is a power system for controlling connection point power at a connection point with a power grid, comprising: a processing unit including a first calculation unit that calculates an induction command value for making the connection point power a target power; and a plurality of power control devices to which corresponding power devices among a plurality of power devices are each connected, wherein each of the plurality of power control devices controls the output power of the corresponding power device based on a common induction command value input from the processing unit, the first calculation unit uses an overall power control width when calculating the induction command value, the overall power control width is the sum of the individual power control widths which are the maximum power that each of the plurality of power devices can output, and the processing unit further includes a first update unit that updates the overall power control width.

[0007] In a preferred embodiment of the power system, the processing unit further includes a communication unit that receives the individual power control width from each of the plurality of power control devices, and a second calculation unit that calculates the value of the overall power control width from the individual power control width received by the communication unit, and the first update unit updates the overall power control width to the updated value calculated by the second calculation unit.

[0008] In a preferred embodiment of the power system, each of the plurality of power control devices communicates with at least one of the other power control devices, performs calculations using internal values ​​based on the individual power control width through such communication, and the first update unit updates the overall power control width to an updated value calculated from the results of the calculations performed by the plurality of power control devices.

[0009] In a preferred embodiment of the power system, the plurality of power control devices include at least one charge / discharge control device to which a power storage device as a power device is connected, the processing device further includes a third calculation unit that calculates a battery capacity constraint based on the battery capacity of the power storage device, the charge / discharge control device controls the output power of charging and discharging the power storage device based on the common induction command value and the battery capacity constraint input from the processing device, the third calculation unit uses the total battery capacity when calculating the battery capacity constraint, the total battery capacity is the sum of the battery capacities of each power storage device, and the processing device further includes a second update unit that updates the total battery capacity. [Effects of the Invention]

[0010] In the power system of this disclosure, the overall power control width is used when calculating the induction command value, and this overall power control width is updated. This overall power control width is the sum of the individual power control widths of multiple power devices, where the individual power control width is the maximum power that each power device can output. As a result, even if a change in the state of a power device occurs, the setting value for calculating the induction command value is updated to a value corresponding to the changed state. Therefore, the power system of this disclosure can continue appropriate energy management even if a change in the state of a power device occurs. [Brief explanation of the drawing]

[0011] [Figure 1] This is an overall configuration diagram showing the power system according to the first embodiment. [Figure 2] This is a flowchart of the signal processing performed by the processing unit of the power system according to the first embodiment. [Figure 3]This is an overall configuration diagram showing a power system according to a modified example of the first embodiment. [Figure 4] This is an overall configuration diagram showing the power system according to the second embodiment. [Figure 5] This is a flowchart of the signal processing performed by the processing unit of the power system according to the second embodiment. [Figure 6] This is an overall configuration diagram showing the power system according to the third embodiment. [Modes for carrying out the invention]

[0012] Preferred embodiments of the power system of this disclosure are described below with reference to the drawings. Hereafter, identical or similar components are denoted by the same reference numerals, and redundant descriptions are omitted.

[0013] Figure 1 shows an example of the overall configuration of a power system S1 according to the first embodiment. As shown in the figure, the power system S1 comprises a power line 90, a processing unit A1, a plurality of power control devices B1, and a detection device C1. In Figure 1, thick lines represent the power network, and dashed lines represent the communication network.

[0014] Power system S1 is connected to connection point K and interconnected to power grid D. Power system S1 receives power from power grid D. In addition, it may also be capable of transmitting power to power grid D (reverse power flow). In this disclosure, when power is being output from power system S1 to power grid D, i.e., when reverse power flow is occurring, the connection point power is assumed to be a positive value. On the other hand, when power is being output from power grid D 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 K between power system S1 and power grid D.

[0015] The power system S1 performs power control such that the connection point power becomes the target power through the cooperation of the processing device A1 and a plurality of power control devices B1. The target power refers to the target value (adjustment target value) of the connection point power. In the power control of the power system S1, the processing device A1 calculates an induction command value for controlling the connection point power to the target power (adjustment target value). The induction command value is common to the plurality of power control devices B1. Each power control device B1 calculates an output target value of the control target (connected power equipment Y) based on the induction command value calculated by the processing device A1. Then, each power control device B1 controls the output power of the control target based on the calculated output target value. Thus, the power system S1 controls the connection point power to the target power (adjustment target value) by the plurality of power control devices B1 performing distributed control of the output power. The induction command value is also for each power control device B1 to calculate the output target value.

[0016] The power load L is supplied with power from the power grid D and each power control device B1. The power load L includes a general load and an important load. The general load includes, for example, electrical equipment that is relatively less affected even if the power is cut off during a disaster. The important load is an important load that needs to continue to be supplied with power even during a disaster, and includes, for example, emergency elevators, electrical equipment that requires continuous operation, building lighting, and air conditioning equipment.

[0017] The power line 90 is appropriately connected to the power grid D, the power load L, and the plurality of power control devices B1. The power line 90 constructs the power network in the power system S1.

[0018] The detection device C1 detects the connection point power. The detection device C1 includes a detection unit 81 and a communication unit 82. The detection unit 81 is installed between the connection point K and the power system D and detects the connection point power. The detection unit 81 is, for example, a power transducer. The detection unit 81 can communicate with the communication unit 82 and outputs the detected value of the connection point power to the communication unit 82. The communication unit 82 includes an AD converter that converts the detected value (analog value) of the connection point power input from the detection unit 81 into a digital value, and transmits the converted detected value (digital value) of the connection point power to the processing device A1. Various protection devices (such as reverse current relays, ground fault relays, reverse power relays, etc.) for connecting the power system S1 to the power system D are further installed in the detection device C1 as appropriate.

[0019] Each of the plurality of power control devices B1 is connected to the connection point K. Each of the plurality of power control devices B1 controls the output power of its own device based on an optimization problem using an induction command value. Each of the plurality of power control devices B1 is connected to an electrical device Y. Each of the plurality of power control devices B1 controls the output power or input power of the electrical device Y. Note that the input power corresponds to the output power with a negative value. In the illustrated example, one electrical device Y is connected to one power control device B1, but a plurality of electrical devices Y may be connected to one power control device B1.

[0020] As shown in FIG. 1, the plurality of power control devices B1 include a battery control device B11 and a plurality of EV control devices B12. EV is an abbreviation for Electric Vehicle. Note that the number of battery control devices B11 and the number of EV control devices B12 are not limited to the illustrated example.

[0021] A battery Y11 as an electrical device Y is connected to the battery control device B11. The battery control device B11 charges and discharges the connected battery Y11. The battery control device B11 charges the battery Y11 by supplying the power input from the connection point K side to the battery Y11. Also, the battery control device B11 discharges the battery Y11 by outputting the power stored in the battery Y11 to the connection point K side.

[0022] The EV control device B12 is connected to an electric vehicle Y12, which acts as a power device Y. The EV control device B12 performs charging and discharging of the connected electric vehicle Y12. Charging and discharging of the electric vehicle Y12 refers to charging and discharging the battery (a battery that supplies power to the electric motor) installed in the electric vehicle Y12. The EV control device B12 charges the electric vehicle Y12 by supplying power input from the connection point K to the electric vehicle Y12. The EV control device B12 also discharges the electric vehicle Y12 by outputting the power stored in the electric vehicle Y12 to the connection point K.

[0023] Each of the multiple power control devices B1 (battery control device B11 and EV control device B12) includes a signal processing unit 11 and a power conversion unit 12. The signal processing unit 11 and power conversion unit 12 described below are common to each of the multiple power control devices B1 unless otherwise specified.

[0024] The signal processing unit 11 can communicate with the processing unit A1 and the connected power equipment Y. The signal processing unit 11 of the battery control device B11 can communicate with the battery Y11, and the signal processing unit 11 of the EV control device B12 can communicate with the electric vehicle Y12.

[0025] The signal processing unit 11 receives an induction command value from the processing unit A1 and calculates the output target value of the power equipment Y based on an optimization problem using the received induction command value. This optimization problem includes an evaluation function and constraints. The evaluation function is the same as that described in Patent Document 1, for example. In this embodiment, the signal processing unit 11 performs the calculations of equations (1) and (2) below, which are derived from the evaluation function, similar to those described in Patent Document 1. In equations (1) and (2) below, P ref is the output target value of power control device B1, pr is the induction command value, pr lmt The `pr` parameter represents the induction command value limit, and `a1` to `a4` represent the design parameters. lmtThe design parameters a1 to a4 are the same as those described in Patent Document 1. Then, similar to the description in Patent Document 1, the output target value is calculated by correcting the calculation result with constraints. The constraints are the same as those described in Patent Document 1. Note that the constraints set for the battery PCS described in Patent Document 1 are set in the signal processing unit 11 of the battery control device B11, and the constraints set for the EV stand described in Patent Document 1 are set in the signal processing unit 11 of the EV control device B12. Alternatively, the signal processing unit 11 may calculate the output target value by solving the evaluation function under the constraints. The signal processing unit 11 outputs the calculated output target value to the power conversion unit 12.

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[0026] Furthermore, the signal processing unit 11 obtains the current individual power control width of the connected power equipment Y. The individual power control width is the power output information of the power equipment Y, and corresponds to the maximum output power of the power equipment Y. When the power equipment Y is not degraded, the individual power control width is, for example, the rated output specified for the power equipment Y. On the other hand, when the power equipment Y is degraded, it becomes a value smaller than the rated output. Also, in the EV control device B12, the individual power control width increases or decreases depending on the connected electric vehicle Y12. The signal processing unit 11 transmits the obtained individual power control width to the processing device A1.

[0027] The power conversion unit 12 controls the output power or input power of the power device Y based on the output target value input from the signal processing unit 11. The power conversion unit 12 of the battery control device B11 controls the charging power or discharging power of the battery Y11. In this disclosure, the power conversion unit 12 of the battery control device B11 discharges the battery Y11 when the received output target value is positive, and charges the battery Y11 when the received output target value is negative. The power conversion unit 12 of the EV control device B12 controls the charging power or discharging power of the electric vehicle Y12. In this disclosure, the power conversion unit 12 of the EV control device B12 discharges the electric vehicle Y12 when the received output target value is positive, and charges the electric vehicle Y12 when the received output target value is negative.

[0028] The processing unit A1 can communicate with each of the multiple power control devices B1 and with the detection device C1. The processing unit A1 monitors the connection point power and calculates an induction command value to control the connection point power to a target power (adjustment target value). The target power (adjustment target value) is set to a value corresponding to the set control mode. The control mode is a setting that determines the system function of the power system S1. Control modes in the power system S1 include, for example, an output suppression mode that suppresses the output of connection point power, a schedule mode that controls connection point power at predetermined time intervals, a peak cut mode that suppresses power supplied from the power grid D, and a reverse power flow avoidance mode that controls connection point power to prevent reverse power flow. Control modes are not limited to these examples. For example, the target power may be set to a value pre-set in the processing unit A1, a value set by user operation, or a value instructed by a higher-level device (e.g., a power company), depending on the control mode. In addition, the connection point power may be a detected value detected by the detection device C1, or an estimated value calculated from the values ​​of each output power obtained by communication from each power control device B1. Furthermore, depending on the control mode set in the processing unit A1, either a detected value or an estimated value may be used as the connection point power. As shown in Figure 1, the processing unit A1 includes a first calculation unit 21, a second calculation unit 221, a first update unit 222, and a communication unit 24.

[0029] The communication unit 24 communicates with each of the multiple power control devices B1 and with the detection device C1. The communication unit 24 receives connection point power from the detection device C1 and individual power control widths from each power control device B1. The communication unit 24 also transmits induction command values ​​to each power control device B1.

[0030] The first calculation unit 21 calculates the induction command value by performing calculations such as those shown in equations (3) to (5) below. In equations (3) to (5) below, pr is the induction command value, λp is the state variable, and P C is the target power (active power), P is the current connection point power (active power), pr(t) is the induction command value, ε is the gradient coefficient, ε Gain ε is the gain for adjusting the gradient coefficient, dPmax is the overall power control width, and Ts is the update interval for the induction command value. Note that equations (3) and (4) below are equivalent to the calculation formulas described in Patent Document 1. The first calculation unit 21 receives the connection point power from the detection device C1 via the communication unit 24 and reads the set values ​​stored in the aforementioned storage or the like for the calculation of equations (3) to (5) below. As can be understood from equations (3) to (5) below, the set values ​​read by the first calculation unit 21 include the overall power control width and the target power (adjustment target value). The first calculation unit 21 transmits the calculated induction command value to each power control device B1 via the communication unit 24.

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[0031] The second calculation unit 221 obtains the individual power control width of each power device Y connected from each power control device B1 via the communication unit 24. Then, it calculates the total power control width by summing the obtained individual power control widths of each power device Y.

[0032] The first update unit 222 updates the overall power control width. For example, the first update unit 222 updates the overall power control width by overwriting the value of the overall power control width stored in the storage (which may also be memory) of the processing unit A1 with the value of the overall power control width (updated value) calculated by the second calculation unit 221.

[0033] Figure 2 is a flowchart showing the signal processing performed by the processing unit A1. The signal processing shown in Figure 2 includes a first process shown in Figure 2(a) and a second process shown in Figure 2(b). The first process is repeated with a period t1, and the second process is repeated with a period t2. The period t1 of the first process is greater than the period t2 of the second process. For example, period t1 is between 10 and 10,000 times the period t2. For example, period t1 is 1 second and period t2 is 1 hour (3600 seconds). Note that the relationship between period t1 and period t2 is not limited to these numerical examples. Period t2 corresponds to the update period Ts of the above-mentioned induction command value.

[0034] The first process is performed by the second calculation unit 221, and mainly involves calculating and updating the overall power control width. As shown in the flowchart in Figure 2(a), in the first process, the second calculation unit 221 first obtains the individual power control width from each power control device B1 via the communication unit 24 (S101). Next, the second calculation unit 221 calculates the overall power control width by summing the individual power control widths obtained from each power control device B1 (S102). In other words, the overall power control width is the sum of the individual power control widths of the multiple power control devices B1. Next, the second calculation unit 221 updates the overall power control width by overwriting the set value of the overall power control width stored in the aforementioned storage with the value of the overall power control width calculated in step S102 (S103). Through the above first process, the overall power control width is updated at each cycle t1 according to the state of the power equipment Y at that time.

[0035] The second process is performed by the first calculation unit 21, and mainly involves calculating and transmitting the induction command value. As shown in the flowchart in Figure 2(b), in the second process, the first calculation unit 21 first acquires the detected value of the current connection point power (S201). Next, the first calculation unit 21 reads out each setting value for calculating the induction command value (S202). The reading of the setting values ​​in step S202 includes reading out the target power (S202a) and the overall power control width (S202b). It also includes reading out other setting values ​​used in equations (3) to (5) above. Next, the first calculation unit 21 calculates the induction command value by performing the calculations in equations (3) to (5) above using the detected value of the connection point power acquired in step S201 and the setting values ​​(including the target power and overall power control width) read out in step S202 (S203). Next, the first calculation unit 21 transmits the induction command value calculated in step S203 to each power control device B1 via the communication unit 24 (S204). Through this second process, the induction command value is updated every period t2, and each power control device B1 controls the output power according to the updated induction command value.

[0036] In power system S1, processing unit A1 includes a first update unit 222 that updates the overall power control width. The overall power control width is the sum of the maximum power (individual power control width) that can be output by each of the multiple power devices Y. In configurations different from power system S1, where the overall power control width is not updated, a difference will occur between the overall power control width at the start of operation and the current overall power control width due to deterioration and failure of each power device Y, as well as the addition and removal of power devices Y. If such a difference occurs and the overall power control width at the start of operation is larger than the current overall power control width, the change in the induction command value will be smaller than the changeable amount, as can be understood from equations (3) to (5) above. As a result, the time required to bring the connection point power to the target power increases, and the speed of power control decreases. Conversely, if the overall power control width at the start of operation is smaller than the current overall power control width, the change in the induction command value will be larger than the changeable amount, as can be understood from equations (3) to (5) above. Therefore, power control overshoot and abnormal power control may occur. In response to this, in power system S1, processing unit A1 periodically (at cycle t1) updates the overall power control width according to the current state of power equipment Y. With this configuration, power system S1 can calculate the inductive command value using the updated overall power control width corresponding to the change in the individual power control width of each power equipment Y and the increase in power equipment Y. In other words, even if power equipment Y deteriorates or fails, or if power equipment Y is added or removed, power system S1 can calculate the inductive command value based on the state after these changes. Therefore, power system S1 can continue to perform appropriate energy management even if the state of connected power equipment Y changes.

[0037] In power system S1, the period t1 of the first process, which updates the overall power control width, is greater than the period t2 of the second process, which calculates and transmits the induction command value. If the period t1 of the first process is less than or equal to the period t2 of the second process, for example, when the connection of electric vehicle Y12 changes frequently, the overall power control width will be updated frequently, resulting in frequent changes in the induction command value. This can cause power control to change frequently in order to bring the connection point power to the target power, potentially leading to power control instability. Therefore, by making the period t1 of the first process greater than the period t2 of the second process, it is possible to suppress power control instability.

[0038] Other embodiments and modifications of the power system of this disclosure are described below. The configurations of the parts in each embodiment and each modification are interchangeable to the extent that no technical inconsistencies arise.

[0039] Figure 3 shows an example of the overall configuration of power system S11 according to a first modified example of the first embodiment. Power system S11 differs from power system S1 in its method of calculating the overall power control width.

[0040] As shown in Figure 3, in the power system S11, each of the multiple power control devices B1 can communicate with at least one of the other power control devices B1. In the illustrated example, each of the multiple power control devices B1 can communicate with all of the other power control devices B1, but the system is not limited to this example; it is sufficient if a communication path exists (connected state) to any two of the power control devices B1.

[0041] In power system S11, the average value of the individual power control widths of multiple power devices Y and the number of power devices Y are calculated through the coordinated control of multiple power control devices B1. The total power control width is then calculated by multiplying the calculated average value of the individual power control widths by the number of power devices Y. "Coordinated control" refers to control performed by multiple power control devices B1 transmitting and receiving information from each other.

[0042] In each power control device B1 of the power system S11, the signal processing unit 11 communicates with other power control devices B1 as described above. The signal processing unit 11 includes a calculation unit 111, as shown in Figure 3. The calculation unit 111 calculates the average value of each individual power control width and the number of power devices Y for a plurality of power equipment Y. In this embodiment, the calculation unit 111 calculates the average value of each individual power control width and the number of power devices Y by performing the following calculation using internal values ​​(hereinafter referred to as "agreement calculation"). The calculation unit 111 generates an internal value Xi and transmits the internal value Xi to the other power control device B1. The calculation unit 111 receives an internal value Xj from the other power control device B1. The calculation unit 111 subtracts the internal value Xi from each received internal value Xj and adds up all the subtraction results. Then, it integrates the summation result to generate a new internal value Xi. As this calculation is repeated, the internal value Xi of each power control device B1 converges to the arithmetic mean of the initial values. Furthermore, the fact that the internal value Xi converges to the arithmetic mean of the initial values ​​through consensus calculation can be understood from the technical concept described in Patent Document 2.

[0043] The calculation unit 111 generates an internal value (hereinafter referred to as the "first internal value") for the individual power control width and performs a consensus calculation using the first internal value so that the first internal value converges to the average value of the individual power control widths. The initial value of the first internal value is obtained from the power equipment Y. As a result, the average value of the individual power control widths of the multiple power equipment Y is calculated in each of the multiple power control devices B1.

[0044] Furthermore, the calculation unit 111 generates an internal value (hereinafter referred to as the "second internal value") for calculating the number of units, and performs a consensus calculation using the second internal value so that the second internal value converges to the reciprocal of the number of power devices Y. The initial value of the second internal value is set to "1" for one of the multiple power control devices B1, and to "0" for the others. As a result, the second internal value converges to the reciprocal of the number of power devices Y in each of the multiple power control devices B1. Then, by taking the reciprocal of the converged second internal value, the number of power devices Y is calculated. The calculation of the number of power devices Y by such a consensus calculation can be understood from the technical concept described in Patent Document 3. Note that the method for calculating the number of units is not limited to a consensus calculation using the second internal value, and other methods may be used. Also, the system may be configured so that the user sets the number of units in the processing unit A1 when the number of units changes.

[0045] The second calculation unit 221 of the power system S11 obtains the average value of the individual power width and the number of power devices Y from one of the multiple power control devices B1. Then, it calculates the total power control width by multiplying the average value of the individual power width by the number of power devices Y.

[0046] As described above, the power system S11 uses the coordinated control of multiple power control devices B1 to find the average value of each individual power control width of multiple power devices Y and the number of multiple power devices Y. Then, the processing device A1 calculates the overall power control width by multiplying the average value of the individual power control widths by the number of multiple power devices Y. Even with this configuration, the overall power control width is updated according to the current state of the power devices Y.

[0047] In power system S11, the overall power control range is updated, similar to power system S1. Therefore, power system S11, like power system S1, can continue to perform appropriate energy management even when the state of the connected power equipment Y changes.

[0048] In power system S11, processing unit A1 calculates the total power control width by multiplying the average value of the individual power control widths received from any of the multiple power control devices B1 by the number of multiple power devices Y. With this configuration, processing unit A1 does not need to receive individual power control widths from each of the multiple power control devices B1. Therefore, processing unit A1 only needs to establish bidirectional communication with at least one of the multiple power control devices B1, and does not need to establish bidirectional communication with all of them. For this reason, even when adding a new power control device B1, it is not necessary to set up bidirectional communication between the power control device B1 and processing unit A1. In other words, power system S11 makes it easy to add a new power control device B1. Note that the calculation time for the total power control width in power system S11 is longer than the calculation time for the total power control width in power system S1. This is because the above-mentioned consensus calculation in power system S11 requires repeating a predetermined calculation. Therefore, power system S1 is preferable to power system S11 in terms of shortening the calculation time for the total power control width.

[0049] In a configuration different from the above modified example, one of the multiple power control devices B1 may multiply the average value of the individual power control widths by the number of multiple power devices Y. In other words, one of the multiple power control devices B1 may calculate the total power control width and transmit the calculated total power control width to the processing device A1. In this case, the computational load on the processing device A1 can be reduced.

[0050] Figure 4 shows an example of the overall configuration of power system S2 according to the second embodiment. Power system S2 differs from power system S1 in that it further performs power control that takes into account the battery capacity of each power device Y (storage battery Y11 and electric vehicle Y12). For this reason, the processing unit A1 of power system S2 further calculates the total battery capacity and transmits a battery capacity constraint based on this total battery capacity to each power control unit B1. The total battery capacity is the sum of the battery capacity of storage battery Y11 and the battery capacity of electric vehicle Y12. The battery capacity constraint is information for defining the upper limit of the C rate. By taking into account the respective battery capacities of storage battery Y11 and electric vehicle Y12, power system S2 realizes the following control: that is, power system S2 realizes control that extends the duration of power output of each power device Y, or control that suppresses an unexpected increase in the output power of power device Y. In this embodiment, an example is shown in which the total battery capacity is calculated without distinguishing between the battery capacity of the storage battery Y11 and the battery capacity of the electric vehicle Y12. However, unlike this example, the total battery capacity may be calculated by separating the battery capacity of the storage battery Y11 and the battery capacity of the electric vehicle Y12. In other words, the total battery capacity for the storage battery Y11 and the total battery capacity for the electric vehicle Y12 may be calculated separately, and battery capacity constraints may be set for the storage battery control device B11 and the EV control device B12. The storage battery control device B11 and the EV control device B12 are examples of the "charge / discharge control device" described in the claims. The storage battery Y11 and the electric vehicle Y12 are examples of the "energy storage device" described in the claims.

[0051] In each power control device B1 of the power system S2, the signal processing unit 11 acquires the battery capacity from the connected power equipment Y (storage battery Y11 or electric vehicle Y12). This battery capacity is called the "individual battery capacity". The signal processing unit 11 transmits the acquired individual battery capacity to the processing unit A1.

[0052] The processing unit A1 of the power system S2 includes a third calculation unit 231 and a second update unit 232, compared to the processing unit A1 of the power system S1.

[0053] The third calculation unit 231 acquires (receives) the individual battery capacity of each power device Y connected from each power control device B1 via the communication unit 24. Then, it calculates the total battery capacity by summing the acquired individual battery capacities of each power device Y.

[0054] The second update unit 232 updates the total battery capacity. For example, the second update unit 232 updates the total battery capacity by overwriting the value of the total battery capacity stored in the storage (which may also be memory) of the processing unit A1 with the value of the total battery capacity calculated by the third calculation unit 231 (updated value).

[0055] Furthermore, the processing unit A1 of the power system S2 is set to an upper limit value (hereinafter referred to as the "output limit") for limiting the output of the power system S2. The first calculation unit 21 uses this output limit and the total battery capacity updated by the second update unit 232 to calculate the battery capacity constraint. The first calculation unit 21 transmits the calculated battery capacity constraint to each power control device B1 via the communication unit 24.

[0056] Figure 5 is a flowchart showing the signal processing performed by the processing unit A1 in addition to the first and second processes. The signal processing shown in Figure 5 includes the third process shown in Figure 5(a) and the fourth process shown in Figure 5(b). The third process is repeated with a period t3, and the fourth process is repeated with a period t4. The period t3 is the same as the period t1 mentioned above, but it may be different from the period t1. For example, the period t3 may be smaller than the period t1. The period t4 is the same as the period t2 mentioned above, but it may be different from the period t2.

[0057] The third process is performed by the third calculation unit 231, and mainly involves calculating and updating the total battery capacity. As shown in the flowchart in Figure 5(a), in the third process, the third calculation unit 231 first obtains the individual battery capacity from each power control device B1 via the communication unit 24 (S301). Next, the third calculation unit 231 calculates the total battery capacity by summing the individual battery capacities obtained from each power control device B1 (S302). In other words, the total battery capacity is the sum of the individual battery capacities of the multiple power devices Y. Next, the third calculation unit 231 updates the total individual battery capacity by overwriting the set value of the total individual battery capacity stored in the aforementioned storage with the value of the total individual battery capacity calculated in step S302 (S303). Through the above third process, the total individual battery capacity is updated every cycle t3 according to the state of the power devices Y at that time. Note that the method for calculating the total battery capacity is not limited to the example described above. Similar to the calculation of the overall power control range of the power system S11, the average value of the individual battery capacities of multiple power devices Y and the number of multiple power devices Y may be calculated by the coordinated control of multiple power control devices B1, and the overall battery capacity may be calculated by multiplying this average value of individual battery capacities by the number of power devices Y.

[0058] The fourth process is performed by the first calculation unit 21, and mainly involves calculating and transmitting the battery capacity constraint. In this embodiment, an example is shown in which the first calculation unit 21 performs the fourth process in addition to the first process, but the fourth process may be performed by elements different from the first calculation unit 21. As shown in the flowchart of Figure 5(b), in the fourth process, the first calculation unit 21 first reads out each setting value for calculating the battery capacity constraint (S401). The reading of the setting values ​​in step S401 includes reading out the output upper limit (S401a) and reading out the total battery capacity (S401b). Next, the first calculation unit 21 calculates the battery capacity constraint by dividing the output upper limit obtained in step S401a by the total battery capacity read out in step S401b (S402). Next, the first calculation unit 21 transmits the battery capacity constraint calculated in step S402 to each power control device B1 via the communication unit 24 (S403). Through the fourth process described above, the battery capacity constraint is updated every period t4, and each power control device B1 controls the output power in accordance with the updated battery capacity constraint, in addition to the induced command value. For example, when each power control device B1 controls the output power of power equipment Y based on the induced command value, if it exceeds the range of the battery capacity constraint, it corrects the output power of power equipment Y so that it falls within the range of the battery capacity constraint.

[0059] In power system S2, the overall power control range is updated, similar to power system S1. Therefore, power system S2, like power system S1, can continue to perform appropriate energy management even when the state of the connected power equipment Y changes.

[0060] The power system S2 includes a second update unit 232 that updates the overall battery capacity. This configuration enables power control that matches changes in the battery capacity of each power device Y (storage battery Y11 and electric vehicle Y12). As a result, the power system S2 can perform control to extend the duration of power output of each power device Y, or control to suppress unexpected increases in the output power of power device Y. In other words, the power system S2 enables more advanced power control.

[0061] Figure 6 shows a power system S3 according to the third embodiment. Power system S3 differs from power system S1 in that it further includes a photovoltaic power generation system and a load control system.

[0062] In the power system S3, the multiple power control devices B1 include a battery control device B11 and an EV control device B12, as well as a photovoltaic power generation control device B13 and a load control device B14. The photovoltaic power generation control device B13 and the load control device B14 each include a signal processing unit 11 and a power conversion unit 12, similar to the battery control device B11 and the EV control device B12.

[0063] A solar cell Y13, which functions as a power device Y, is connected to the solar power generation control device B13. The power conversion unit 12 of the solar power generation control device B13 controls the output power of the solar cell Y13. The aforementioned solar power generation system consists of the solar power generation control device B13 and the solar cell Y13. The signal processing unit 11 of the solar power generation control device B13 obtains the individual output control width of the solar cell Y13 from the solar cell Y13 and transmits it to the processing unit A1.

[0064] A controllable load Y14, which is a power device Y, is connected to the load control device B14. The controllable load Y14 is a load whose power consumption can be controlled by the load control device B14. The power conversion unit 12 of the load control device B14 controls the output power of the controllable load Y14 by controlling the power consumption of the controllable load Y14. The aforementioned load control system consists of the load control device B14 and the controllable load Y14. The signal processing unit 11 of the load control device B14 acquires the individual output control width of the controllable load Y14 from the controllable load Y14 and transmits it to the processing unit A1.

[0065] The processing unit A1 (second calculation unit 221) of the power system S3 also includes the individual power control width of the solar cell Y13 received from the photovoltaic power generation control device B13 and the individual power control width of the controllable load Y14 received from the load control device B14 when calculating the overall power control width.

[0066] In power system S3, the overall power control range is updated, similar to power system S1. Therefore, power system S3, like power system S1, can continue to perform appropriate energy management even when the state of the connected power equipment Y changes.

[0067] In power system S3, the overall power control range includes the individual power control range for solar cell Y13 and the individual power control range for controllable load Y14. This configuration allows for increasing or decreasing the output power of battery Y11 and electric vehicle Y12 by considering the output power of solar cell Y13 and controllable load Y14. Therefore, power system S3 can perform appropriate energy management that is more in line with the user's operational policy. For example, power system S3 enables power control that prioritizes charging of battery Y11 and power control that suppresses discharge of electric vehicle Y12. Furthermore, this configuration allows for continued appropriate energy management even if there is degradation or failure of solar cell Y13 and controllable load Y14, or changes in state due to the addition or removal of solar cell Y13 and controllable load Y14.

[0068] 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]

[0069] S1, S11, S2, S3: Power system, A1: Processing unit, 21: First calculation unit, 221: Second calculation unit, 222: First update unit, 231: Third calculation unit, 232: Second update unit, 24: Communication unit, B1: Power control device, B11: Battery control device, B12: EV control device, Y: Power equipment, Y11: Battery, Y12: Electric vehicle

Claims

1. A power system that controls the connection point power at the connection point with the power grid, A processing unit including a first calculation unit that calculates an induction command value to make the connection point power a target power, Multiple power control devices, each connected to a corresponding power device among multiple power devices, Equipped with, Each of the plurality of power control devices controls the output power of the corresponding power device based on a common induction command value input from the processing device. The first calculation unit uses the total power control width when calculating the induction command value. The overall power control width is the sum of the individual power control widths, which are the maximum power output of each of the multiple power devices. The processing device further includes a first update unit for updating the overall power control width, comprising a power system.

2. The processing apparatus further includes a communication unit that receives the individual power control width from each of the plurality of power control devices, and a second calculation unit that calculates the value of the overall power control width from the individual power control width received by the communication unit. The power system according to claim 1, wherein the first update unit updates the overall power control width to an updated value calculated by the second calculation unit.

3. Each of the aforementioned plurality of power control devices communicates with at least one of the other power control devices, and through such communication performs an agreement calculation using an internal value generated with the individual power control width of the corresponding power equipment as the initial value. In the aforementioned agreement calculation, a communication process is performed in which the generated internal value is transmitted to at least one other power control device and the internal value of the power control device is received from at least one other power control device, and an update process is performed in which a new internal value is generated by calculation using the difference between the generated internal value and the received internal value. The aforementioned internal value converges to the average value of the individual power control widths of the plurality of power devices. The power system according to claim 1, wherein the first update unit updates the overall power control width to an updated value calculated from the average value which is the result of the consensus calculation performed by the plurality of power control devices.

4. The plurality of power control devices include at least one charge / discharge control device to which the energy storage device as a power device is connected. The processing apparatus further includes a third calculation unit that calculates a battery capacity constraint based on the battery capacity of the energy storage device, The charge / discharge control device controls the output power of the charge / discharge of the energy storage device based on the common induction command value and the battery capacity constraint input from the processing device. The third calculation unit uses the total battery capacity when calculating the battery capacity constraint. The total battery capacity is the sum of the battery capacities of each of the energy storage devices. The power system according to any one of claims 1 to 3, wherein the processing device further includes a second update unit for updating the overall battery capacity.

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