Power supply device

Abstract

The first power converter (7) selectively performs a charging operation for converting a portion of the first AC power from the power system (200) to DC power and storing the DC power in the power storage device (130), and a discharging operation for converting the DC power of the power storage device (130) to second AC power. The control device (23) is communicatively connected to a server (210) that adjusts power supply / demand in a power system (200). When the power system (200) is sound, the control device (23) controls the charging operation so that the power storage device (130) is fully charged. The control device (23) controls the discharge operation so as to supply the total power of the first AC power and the second AC power to the load when receiving an advance notification signal of the demand response from the server (210), and stops the discharge operation in response to the SOC of the power storage device (130) falling to the standby SOC. The control device (23) controls the discharge operation or the charge operation on the basis of the demand response command received from the server (210).

Description

Technical Field

[0001] The invention relates to a power supply device. Background Art

[0002] For example, Japanese Patent Application Laid-Open No. 8-289470 (Patent Document 1) discloses a power supply device that supplies power from a commercial power supply to a load. The power supply device includes an uninterruptible power supply device that supplies power stored in a power storage device to a load when the commercial power supply fails, a demand monitoring device that monitors the power usage (demand) of the load, and a demand control device. The demand control device is configured to calculate the remaining power of the uninterruptible power supply device when it is predicted that the power usage of the load exceeds the contracted power, and supply the calculated remaining power to the load.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Laid-Open No. 8-289470 Summary of the invention

[0006] Problems to be solved by the invention

[0007] In recent years, in order to adjust the balance between the demand and supply of electricity in the power system, demand response (DR) has been proposed to control the power usage of the demand side. In a certain aspect, the power company cooperates with the aggregator to make a specified request to each demand side through DR instructions, thereby adjusting the balance of power supply and demand. DR instructions include DR instructions for requesting an increase in the power demand and DR instructions for requesting a decrease in the power demand.

[0008] The demand side charges and discharges the power storage device according to the DR instruction from the aggregator, thereby contributing to the supply and demand adjustment of the power system. However, on the other hand, the SOC (State Of Charge) of the power storage device changes due to the execution of DR. Therefore, if a power outage occurs in the power system during or after the execution of DR, the power storage device may not store the power required for power outage compensation. In this case, the original power outage compensation function of the power supply device is damaged, so there is a concern that it will become impossible to supply stable AC power to the load.

[0009] The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a power supply device that can ensure power supply to a load when a power failure occurs in the power system and can contribute to the supply and demand adjustment of the power system.

[0010] Means for solving problems

[0011] A power supply device of one embodiment of the present invention is connected between a power system and a load. When the power system is healthy, the power supply device supplies the first AC power supplied from the power system to the load, and when the power system is out of power, the power supply device supplies the second AC power to the load. The power supply device includes a first power converter and a control device. The first power converter is configured to selectively perform a charging operation of converting a part of the first AC power into DC power and storing it in a power storage device, and a discharging operation of converting the DC power of the power storage device into the second AC power. The control device is connected to a server for adjusting power supply and demand in the power system for communication. When the power system is out of power, the control device controls the discharging operation in the first power converter in such a way that the second AC power is supplied to the load. An SOC reference value and a standby SOC greater than the SOC reference value are set in the power storage device, and the SOC reference value is greater than the SOC required to supply the second AC power from the power storage device to the load from the time when the power system is out of power to the time when a predetermined compensation time has passed. When the power system is healthy, the control device controls the charging operation in the first power converter in such a way that the power storage device is fully charged. When receiving a demand response notification signal for adjusting the demand amount in the power system from the server, the control device controls the discharge operation in the first power converter in such a manner that the total power of the first AC power and the second AC power is supplied to the load. The control device stops the discharge operation in accordance with the fact that the SOC of the power storage device is reduced to the standby SOC. The control device controls the discharge operation or the charging operation in the first power converter in accordance with the demand response instruction received from the server.

[0012] Effects of the Invention

[0013] According to the present invention, it is possible to provide a power supply device that can ensure power supply to a load when a power failure occurs in the power system and can contribute to supply and demand adjustment in the power system. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a diagram showing the configuration of a power supply device according to an embodiment of the present invention.

[0015] Figure 2 It is a diagram showing an example of the hardware configuration of the control device.

[0016] Figure 3 This is a diagram for explaining the operation of MPC when the power system is healthy.

[0017] Figure 4 This is a diagram for explaining the operation of the MPC when the power system fails.

[0018] Figure 5This is a diagram for explaining the operation of the MPC when a DR reduction instruction is received.

[0019] Figure 6 It is a diagram for explaining the charge and discharge control of the power storage device when the DR is reduced.

[0020] Figure 7 It is a diagram for explaining the operation of the MPC when a DR increase instruction is received.

[0021] Figure 8 This is a diagram for explaining the charge and discharge control of the power storage device when the DR is increased.

[0022] Fig. 9 1 is a flowchart showing a processing procedure for charge and discharge control of an electric device in the present embodiment.

[0023] Fig.10 1 is a flowchart showing a processing procedure for charge and discharge control of the power storage device in the present embodiment.

[0024] Fig.11 It is a diagram showing the configuration of a power supply device according to a modified example of the present embodiment. DETAILED DESCRIPTION

[0025] Embodiments of the present invention will be described in detail with reference to the accompanying drawings. In addition, the same reference numerals are attached to the same or corresponding parts in the drawings, and their description will not be repeated.

[0026] <Power supply unit configuration>

[0027] Figure 1 FIG. 2 is a diagram showing the configuration of a power supply device according to an embodiment of the present invention. Figure 1 In the present invention, a multiple power compensator (MPC) is described as one form of a power supply device.

[0028] like Figure 1 As shown, MPC 110 is installed in a customer 100 that receives power supply from power system 200. In customer 100, load 120, power storage device 130, and communication device 140 are also installed.

[0029] MPC110 is a device connected between the power system 200 and the load 120, and is used to supply stable AC power to the load 120 without interruption when the AC voltage supplied from the power system 200 decreases or becomes zero for a relatively short time (for example, less than 1 second) (instantaneous voltage drop or instantaneous power outage).

[0030] In addition, when the AC voltage supplied from the power system 200 becomes zero for a relatively long time (for example, more than 1 second) (power outage), the device that supplies AC power to the load 120 is called an uninterruptible power supply (UPS). In this specification, MPC and UPS are collectively referred to as "power supply devices". In addition, in this specification, instantaneous voltage reduction, instantaneous power outage, and power outage of the power system 200 are collectively referred to as "power outage".

[0031] The MPC 110 includes an input terminal T1 , an output terminal T2 , a DC terminal T3 , VCBs (Vacuum Circuit Breakers) 1 , 5 , 6 , and 21 , a high speed switch (HSS) 2 , a power converter 7 , a transformer 20 , an operation unit 22 , and a control device 23 .

[0032] Input terminal T1 receives AC voltage VI of a commercial frequency supplied from power system 200. The instantaneous value of AC voltage VI is detected by control device 23. Control device 23 determines that a power outage of AC voltage VI has occurred when AC voltage VI falls below a lower limit value.

[0033] The output terminal T2 is connected to a load 120. The load 120 is driven by an AC voltage VO supplied from the output terminal T2. The instantaneous value of the AC voltage VO is detected by the control device 23.

[0034] The DC terminal T3 is connected to the power storage device 130. The power storage device 130 stores DC power. The power storage device 130 is, for example, a secondary battery such as a lithium ion battery. However, a lead acid battery may be used instead of a lithium ion battery. In addition, an electric double layer capacitor may be used instead of a secondary battery. The DC voltage VB of the DC terminal T3 is detected by the control device 23. The DC voltage VB is equivalent to the terminal voltage of the power storage device 130 (hereinafter also referred to as "battery voltage").

[0035] The MPC 110 is used to receive a three-phase AC voltage from the power system 200 and supply the three-phase AC voltage to the load 120. However, in order to simplify the drawings and descriptions, the MPC 110 is not shown in FIG. Figure 1 Only one phase of the circuit is shown.

[0036] VCB1, high-speed switch 2, and VCB5 are connected in series between input terminal T1 and output terminal T2. VCB1 and 5 are turned on during normal operation of MPC 110, and are turned off during maintenance of high-speed switch 2 or bypass power supply, for example.

[0037] The high-speed switch 2 includes a semiconductor switch and a mechanical switch connected in series. The semiconductor switch and the mechanical switch are controlled by the control device 23, and are turned on when the AC voltage VI is normal (when the power system 200 is healthy), and are turned off when the AC voltage VI is abnormal (when the power system 200 is out of power).

[0038] Compared with a mechanical switch, a semiconductor switch has characteristics such as a faster operating speed and a lower withstand voltage. Compared with a semiconductor switch, a mechanical switch has characteristics such as a slower operating speed and a higher withstand voltage. By connecting a semiconductor switch and a mechanical switch in series, a high-speed switch 2 is formed that is instantly turned off when a momentary low occurs and has a higher withstand voltage.

[0039] VCB6 is connected between input terminal T1 and output terminal T2. VCB6 is turned off during normal operation of MPC 110, and turned on during bypass power supply, for example. When VCB6 is turned on, AC voltage VI is supplied from power system 200 to load 120 via VCB6, and load 120 is operated.

[0040] The power converter 7 includes a bidirectional converter 8, a current detector 10, a reactor 11, and a capacitor 12. The DC terminal 8a of the bidirectional converter 8 is connected to the DC terminal T3, and the AC terminal 8b thereof is connected to the primary winding 20a of the transformer 20 via the reactor 11. The secondary winding 20b of the transformer 20 is connected to the node N1 between the high-speed switch 2 and VCB5 via VCB21. The instantaneous value of the AC voltage VAC appearing in the primary winding 20a of the transformer 20 is detected by the control device 23. The power converter 7 corresponds to an embodiment of the “first power converter”.

[0041] The bidirectional converter 8 is a well-known converter including a plurality of semiconductor switching elements and a plurality of diodes, and is controlled by, for example, PWM (Pulse Width Modulation) by the control device 23. By turning on and off each semiconductor switching element included in the bidirectional converter 8 at a predetermined frequency, AC power can be converted into DC power, or vice versa, DC power can be converted into AC power.

[0042] In one aspect, when the power system 200 is healthy, the bidirectional converter 8 converts the AC power supplied from the power system 200 via the VCB1, the high-speed switch 2, the VCB21, the transformer 20, and the reactor 11 into DC power and stores it in the power storage device 130. When the power system 200 is out of power, the bidirectional converter 8 converts the DC power of the power storage device 130 into AC power and outputs it to the AC terminal 8b. The AC power is supplied to the load 120 via the reactor 11, the transformer 20, and the VCB21, 5. In this way, the bidirectional converter 8 is configured to selectively perform a charging operation for storing DC power in the power storage device 130 and a discharging operation for supplying the DC power of the power storage device 130 to the load 120.

[0043] Current detector 10 detects current IL flowing through reactor 11 , and transmits signal ILf indicating the detected value to control device 23 .

[0044] Reactor 11 and capacitor 12 constitute an AC filter. This AC filter is a low-pass filter that allows commercial frequency current to pass and cuts off the switching frequency current generated by bidirectional converter 8. In other words, the AC filter converts the output voltage of bidirectional converter 8 into a sinusoidal AC voltage VAC.

[0045] The transformer 20 exchanges AC power between the node N1 and the power converter 7. The VCB 21 is turned on during normal operation of the MPC 110, and is turned off during maintenance of the high-speed switch 2 or the power converter 7, for example.

[0046] The operation unit 22 includes a plurality of buttons, a plurality of switches, a display, etc. The user of the MPC 110 can instruct the start, stop, automatic operation, manual operation, etc. of the MPC 110 by operating the operation unit 22, or can perform various condition settings, etc. The operation unit 22 sends a signal indicating the user's instruction, etc. to the control device 23.

[0047] The control device 23 controls the entire MPC 110 based on a signal from the operation unit 22 , the AC voltages VI, VO, and VAC, the DC voltage VB, an output signal ILf of the current detector 10 , and the like.

[0048] In one aspect, when the power system 200 is healthy, the control device 23 controls the bidirectional converter 8 so that the DC voltage (battery voltage) VB at the DC terminal T3 becomes the reference DC voltage VBr based on the AC voltage VAC, the DC voltage VB, and the output signal ILf of the current detector 10. When the power system 200 is out of power, the control device 23 controls the bidirectional converter 8 so that the AC voltage VO at the output terminal T2 becomes the reference AC voltage VOr.

[0049] Figure 2 2 is a diagram showing an example of the hardware configuration of the control device 23. Typically, the control device 23 can be configured by a microcomputer in which a predetermined program is stored in advance.

[0050] For example, Figure 2 As shown, the control device 23 includes a CPU (Central Processing Unit) 230, a memory 232, and an input / output (I / O) circuit 234. The CPU 230, the memory 232, and the I / O circuit 234 can mutually transmit and receive data via a bus 236. A program is pre-stored in a part of the memory 232, and various functions can be realized by executing the program by the CPU 230.

[0051] Or, with Figure 2 Different from the example of FIG. 1 , at least a part of the control device 23 may be formed using a circuit such as an FPGA (Field Programmable Gate Array) or an ASIC (Application Specific Integrated Circuit). In addition, at least a part of the control device 23 may be formed using an analog circuit.

[0052] return Figure 1 The control device 23 is connected to the communication device 140 so as to be able to communicate. The communication device 140 is a device that can communicate with the aggregator server 210 via a communication network (not shown), and processes various information with the aggregator server 210.

[0053] The aggregator server 210 is a server managed and operated by an aggregator. An aggregator is a business that aggregates energy resources owned by multiple consumers and stands between consumers and power companies to adjust the balance between power demand and supply and maximize the use of energy resources of each consumer.

[0054] By cooperating with aggregators, power companies can adjust the balance of power supply and demand based on demand response (hereinafter also referred to as "DR"). DR is a method of adjusting the balance of power supply and demand by making a specified request to each demand party based on a demand response instruction (hereinafter also referred to as a "DR instruction"). DR instructions include DR instructions requesting an increase in power demand (hereinafter also referred to as an "increase DR instruction") and DR instructions requesting a reduction in power demand (hereinafter also referred to as a "decrease DR instruction").

[0055] For example, on hot summer days or cold winter days, when the demand for electricity increases sharply and the supply and demand are tight, the power company requests the aggregator to reduce the demand for electricity. The aggregator receives the request and outputs a DR reduction instruction to the demand parties under its jurisdiction. The electricity that is suppressed through the cooperation of each demand party is aggregated by the aggregator and provided to the power company.

[0056] When the supply of electricity exceeds the demand due to the increase in power generation from renewable energy sources such as solar power generation and wind power generation, the power company requests the aggregator to increase the demand for electricity. The aggregator receives the request and issues a DR increase instruction to the demand side under its jurisdiction.

[0057] Each demander can be compensated by cooperating with DR in response to such a request. The aggregator becomes an intermediary that collects compensation from the power company and pays each demander.

[0058] The aggregator server 210 includes a control device 212, a storage device 214, and a communication device 216. The control device 212 includes a processor, and is configured to control the communication device 216 while performing predetermined information processing. The storage device 214 is configured to be able to store various information. The communication device 216 includes various communication I / Fs. The control device 212 is configured to communicate with the outside via the communication device 216.

[0059] In this embodiment, when the power system 200 is healthy, the control device 23 is configured to control the bidirectional converter 8 according to the received DR instruction (DR increase instruction or DR decrease instruction) when receiving a DR instruction (DR increase instruction or DR decrease instruction) from the aggregator server 210 via the communication device 140.

[0060] Specifically, when receiving the DR reduction instruction from the aggregator server 210, the control device 23 controls the bidirectional converter 8 so that the total power of the AC power supplied from the power system 200 and the AC power supplied from the power storage device 130 via the bidirectional converter 8 is supplied to the load 120. In this way, by making a part of the AC power supplied to the load 120 be borne by the DC power of the power storage device 130, the AC power supplied from the power system 200 to the demand side 100 can be reduced. As a result, the demand side 100 can contribute to suppressing the demand for power requested from the power company and can receive compensation corresponding to the contribution amount.

[0061] In addition, when receiving the DR increase instruction from the aggregator server 210, the control device 23 controls the bidirectional converter 8 so as to perform the charging operation of accumulating DC power in the power storage device 130. Thus, by supplying the total power of the AC power supplied to the load 120 and the power stored in the power storage device 130 from the power system 200, the AC power supplied from the power system 200 to the demand side 100 can be increased. As a result, the demand side 100 can contribute to the increase in the power demand amount requested by the power company and can obtain compensation corresponding to the contribution amount.

[0062] However, the SOC (State Of Charge) of the power storage device 130 changes by charging and discharging the power storage device 130 according to the DR instruction from the aggregator server 210. Therefore, when a power outage occurs in the power system 200 during or after the execution of DR, the power storage device 130 may not store the power required for power outage compensation. In this case, the original power outage compensation function of the MPC 110 is damaged, and thus stable AC power may not be supplied to the load 120.

[0063] To avoid this, MPC 110 of the present embodiment performs charge and discharge control of power storage device 130 so as to contribute to supply and demand adjustment of power system 200 requested by the power company while ensuring power outage compensation for load 120 .

[0064] <MPC Operation>

[0065] Next, Figure 1 The operation of the MPC 110 shown will be described.

[0066] Figure 3 as well as Figure 4 This is a diagram for explaining the operation during normal operation of the MPC 110. During normal operation, VCB1 and 5 are turned on, and VCB6 (not shown) is turned off. Figure 3 The arrows in FIG. 1 indicate the flow of power supplied from MPC 110 to load 120 when power system 200 is healthy. When power system 200 is healthy, HSS2 is turned on, AC power is supplied from power system 200 to load 120 via VCB1, HSS2, and VCB5, and load 120 operates.

[0067] Furthermore, AC power is supplied from power grid 200 to power converter 7 via VCB1 , HDD 2 , and VCB 21 , and the AC power is converted into DC power by bidirectional converter 8 and stored in power storage device 130 .

[0068] Control device 23 controls bidirectional converter 8 so that DC voltage (battery voltage) VB at DC terminal T3 becomes reference DC voltage VBr. Reference DC voltage VBr is set based on the OCV of power storage device 130 when power storage device 130 is fully charged (SOC=100%) in its OCV-SOC curve.

[0069] exist Figure 3 2 shows a case where the power consumption of load 120 is 100% and 100% of the power is supplied from power system 200. It is assumed that power storage device 130 is fully charged and the current flowing to power storage device 130 is sufficiently small.

[0070] Figure 4 Flow of electric power supplied from MPC 110 to load 120 when power grid 200 fails is indicated by arrows. When power grid 200 fails, HSS 2 is shut down, and power grid 200 and load 120 are disconnected.

[0071] Control device 23 controls bidirectional converter 8 so that AC voltage VO at output terminal T2 becomes reference AC voltage VOr. Thus, 100% of the power is supplied from power storage device 130 to power converter 7, and 100% of the power is supplied from power converter 7 to load 120. Therefore, operation of load 120 continues.

[0072] Figure 5 1 is a diagram for explaining the operation of the MPC 110 when a DR reduction instruction is received from the aggregator server 210 . Figure 5 Flow of electric power supplied from MPC 110 to load 120 is indicated by arrows.

[0073] exist Figure 5 In the embodiment of the present invention, when the power consumption of the load 120 is 100%, 80% of the power is supplied from the power system 200 to the load 120 by reducing the DR. The control device 23 controls the bidirectional converter 8 so that the AC voltage VO of the output terminal T2 becomes the reference AC voltage VOr. As a result, 20% of the power is supplied from the power storage device 130 to the load 120 via the power converter 7. That is, 80% of the power supplied from the power system 200 and 20% of the power supplied from the power storage device 130 are added together, and thus 100% of the power is supplied to the load 120.

[0074] Figure 6 1 is a diagram for explaining the charge and discharge control of power storage device 130 when the DR is reduced. Figure 6 The diagram schematically shows how the SOC of power storage device 130 changes due to charge and discharge control.

[0075] like Figure 6As shown, the SOC of power storage device 130 is set with determination values ​​SOCmin, SOCbackup, SOCwait, and SOCmax which are reference values ​​for controlling charging and discharging of power storage device 130. SOC=0% corresponds to an empty state of power storage device 130, and SOC=100% corresponds to a fully charged state of power storage device 130.

[0076] A prohibition region is set for SOC, in which discharge of power storage device 130 is prohibited in order to prevent overdischarge. SOCmin is set based on this prohibition region. When SOC<SOCmin, discharge of power storage device 130 is prohibited.

[0077] A prohibited area is further set for the SOC, in which charging of the power storage device 130 is prohibited during the execution of DR. When charging a secondary battery such as a lithium-ion battery, generally speaking, constant current charging is switched to constant voltage charging according to the SOC. Specifically, constant current charging is performed to keep the charging current constant at the initial stage of charging. Then, during the execution of constant current charging, when the SOC reaches a specified value, constant current charging is switched to constant voltage charging to keep the battery voltage constant.

[0078] During the execution of constant voltage charging, the charging current becomes smaller than that of constant current charging, so the charging power is limited. Therefore, during the execution of the DR increase described later, the power storage device 130 switches from constant current charging to constant voltage charging, which may cause the power storage device 130 to be unable to receive power corresponding to the power adjustment amount (DR increase amount) requested from the aggregator. If SOC>SOCmax is achieved during the execution of DR increase for the stabilization of power adjustment, the control device 23 stops the charging of the power storage device 130. SOCmax corresponds to an embodiment of the "SOC upper limit value". SOCmax can be set, for example, based on the SOC when the power storage device 130 switches from constant current charging to constant voltage charging.

[0079] SOCbackup is an SOC used to guarantee the function of MPC110 as a backup power source when the power system 200 is out of power (power outage compensation function). SOCbackup is set to a storage capacity greater than or equal to the power outage compensation capacity. The power outage compensation capacity refers to the storage capacity required to continue to supply power from the power storage device 130 to the load 120 over a predetermined compensation time when a power outage occurs in the power system 200. Therefore, in order to guarantee the power outage compensation function, the SOC needs to be maintained at or above SOCbackup when the power system 200 is healthy. SOCbackup corresponds to an embodiment of the "SOC reference value".

[0080] SOCbackup is set to be greater than SOCmin and less than SOCmax. Figure 5 As shown, when the DR is reduced, the power storage device 130 can bear part of the power supplied to the load 120 while ensuring the storage capacity for power outage compensation. In addition, when the DR is increased as described later, part of the power supplied from the power system 200 can be stored in the power storage device 130 while ensuring the storage capacity for power outage compensation.

[0081] SOCwait is set to be larger than SOCbackup and smaller than SOCmax. SOCwait corresponds to a "standby SOC" which is a state in which power storage device 130 is previously made capable of responding to either a charging operation or a discharging operation in order to execute DR.

[0082] Figure 6 The relationship between the SOC of the power storage device 130 and the DC voltage (battery voltage) VB of the DC terminal T3 is shown. The battery voltage VB is based on the OCV-SOC curve of the power storage device 130. The voltage VB1 corresponds to the OCV when the SOC becomes SOCmin in the OCV-SOC curve. The voltage VB2 corresponds to the OCV when the SOC becomes SOCbackup in the OCV-SOC curve. The voltage VB3 corresponds to the OCV when the SOC becomes SOCwait in the OCV-SOC curve. The voltage VB4 corresponds to the OCV when the SOC becomes SOCmax in the OCV-SOC curve. The voltage VB5 corresponds to the OCV when SOC=100% in the OCV-SOC curve.

[0083] During normal operation, the control device 23 sets the target voltage of the battery voltage VB, that is, the reference DC voltage VBr, to VB5, and controls the bidirectional converter 8 so that the battery voltage VB becomes the reference DC voltage VBr (=VB5). As a result, the SOC of the power storage device 130 is maintained at 100% (fully charged state). However, when the DR starts to be increased in response to a request from the aggregator, if the SOC of the power storage device 130 is in the fully charged state, the power storage device 130 becomes unable to receive a part of the power supplied from the power system 200.

[0084] Therefore, when the control device 23 receives a DR notification signal announcing the start of DR from the aggregator server 210 before the execution of DR, it controls the bidirectional converter 8 so that the total power of the AC power supplied from the power system 200 and the AC power supplied from the power storage device 130 via the bidirectional converter 8 is supplied to the load 120.

[0085] The bidirectional converter 8 performs the discharge operation of the power storage device 130, thereby reducing the SOC of the power storage device 130. When the SOC is reduced to SOCwait, the control device 23 stops the operation of the bidirectional converter 8, thereby stopping the discharge of the power storage device 130. In addition, the timing at which the aggregator server 210 transmits the DR notice signal can be set to a timing of a predetermined time reversed from the start timing of DR.

[0086] Thus, when receiving the DR advance signal, the SOC of power storage device 130 is reduced to SOCwait before executing DR, so that when DR is increased, power storage device 130 can receive part of the power supplied from power system 200. In addition, since SOCwait is greater than SOCbackup, the storage amount for power outage compensation can be ensured.

[0087] exist Figure 6 In the embodiment, when receiving the DR reduction instruction after receiving the DR notice signal, the control device 23 controls the bidirectional converter 8 according to the power adjustment amount (DR reduction amount) requested from the aggregator so that the total power of the AC power supplied from the power system 200 and the AC power supplied from the power storage device 130 via the bidirectional converter 8 is supplied to the load 120. The bidirectional converter 8 performs the discharge operation of the power storage device 130, thereby reducing the SOC of the power storage device 130.

[0088] When the SOC of the power storage device 130 decreases below SOCbackup, the control device 23 transmits a DR disabled signal to the aggregator server 210 to indicate that the DR cannot be further reduced. Then, the control device 23 stops the discharge of the power storage device 130 by stopping the operation of the bidirectional converter 8.

[0089] In the case where a power outage of the power system 200 occurs after the execution of the DR reduction, as shown in FIG. Figure 4 As shown, bidirectional converter 8 discharges power storage device 130, thereby supplying power from power storage device 130 to load 120 via power converter 7. At this time, since power storage device 130 has a power failure compensation amount stored, load 120 can be driven over the compensation time.

[0090] Figure 7 This is a diagram for explaining the operation of the MPC 110 when receiving a DR increase instruction from the aggregator server 210 . Figure 7 Flow of electric power supplied from MPC 110 to load 120 is indicated by arrows.

[0091] exist Figure 7In the embodiment, when the power consumption of the load 120 is 100%, 120% of the power is supplied from the power system 200 by increasing the execution of DR. The control device 23 sets the reference DC voltage VBr to VB4, and controls the bidirectional converter 8 so that the battery voltage VB becomes the reference DC voltage VBr (=VB4). Thus, 100% of the 120% of the power supplied from the power system 200 is supplied to the load 120, and the remaining 20% ​​of the power is supplied to the power storage device 130 via the power converter 7.

[0092] Figure 8 1 is a diagram for explaining the charge and discharge control of power storage device 130 when the DR is increased. Figure 8 The diagram schematically shows how the SOC of power storage device 130 changes due to charge and discharge control.

[0093] Before receiving the DR notice signal from the aggregator server 210, the control device 23 sets the reference DC voltage VBr, which is the target voltage of the battery voltage VB, to VB5 and controls the bidirectional converter 8 so that the battery voltage VB becomes the reference DC voltage VBr (= VB5). Thus, the SOC of the power storage device 130 is maintained at 100%.

[0094] When receiving the DR warning signal, the control device 23 controls the bidirectional converter 8 so that the total power of the AC power supplied from the power system 200 and the AC power supplied from the power storage device 130 via the bidirectional converter 8 is supplied to the load 120. The SOC of the power storage device 130 is reduced by the bidirectional converter 8 performing the discharge operation of the power storage device 130. When the SOC of the power storage device 130 is reduced to SOCwait, the control device 23 stops the operation of the bidirectional converter 8, thereby stopping the discharge of the power storage device 130.

[0095] When receiving a DR increase instruction after receiving the DR advance signal, the control device 23 controls the bidirectional converter 8 according to the DR increase amount requested from the aggregator so that part of the AC power supplied from the power system 200 is supplied to the power storage device 130. By performing the charging operation of the power storage device 130 by the bidirectional converter 8, the SOC of the power storage device 130 increases.

[0096] When the SOC of the power storage device 130 reaches SOCmax, the control device 23 transmits a DR impossible signal to the aggregator server 210 to indicate that the DR cannot be further increased. Then, the control device 23 stops the operation of the bidirectional converter 8 to stop charging of the power storage device 130.

[0097] Fig. 9 as well as Fig.101 is a flowchart showing the processing steps of the charge and discharge control of the power storage device 130 in the present embodiment. This flowchart is called from the main routine and executed when a predetermined condition is satisfied, for example. In the figure, the left side shows the processing executed by the aggregator server 210, and the right side shows the processing executed by the MPC 110 (control device 23). Each step is implemented by software processing performed by the aggregator server 210 or the control device 23, but can also be implemented by hardware configured in the aggregator server 210 or the control device 23. Hereinafter, the step is abbreviated as S.

[0098] In S01, when the aggregator server 210 requests the power company to adjust the supply and demand of the power system 200, it obtains the content of the power adjustment. The content of the power adjustment includes the type of DR (increasing DR, reducing DR), the DR amount (power adjustment amount), and the DR period (DR start time and DR end time).

[0099] In S02, the aggregator server 210 sets the type of DR, the amount of DR, and the DR period requested for each demand party. After the processing of S02, the aggregator server 210 waits for the start of the DR period.

[0100] In S03, the aggregator server 210 determines whether it is the DR forecast timing. The DR forecast timing is a timing that is calculated backwards by a predetermined time from the DR start time.

[0101] When the DR forecast timing comes (when it is determined to be yes in S03), the aggregator server 210 sends a DR forecast signal to the demand side 100 in S04. The DR forecast signal is a signal that forecasts the start of DR. After sending the DR forecast signal, when it is the start time of the DR reduction period (when it is determined to be yes in S05), the aggregator server 210 sends a DR reduction instruction to the demand side 100 in S06.

[0102] In MPC 110 , when control device 23 receives the DR notice signal from aggregator server 210 (YES in S21 ), control device 23 controls bidirectional converter 8 in S22 to perform a discharge operation of supplying power stored in power storage device 130 to load 120 .

[0103] During discharge, control device 23 determines in S23 whether SOC of power storage device 130 decreases to or below SOCwait. If SOC decreases to or below SOCwait (YES in S23), control device 23 stops the operation of bidirectional converter 8 in S24, thereby stopping discharge of power storage device 130.

[0104] After receiving the DR notice signal, when the control device 23 receives a DR reduction instruction from the aggregator server 210 (if it is determined to be YES in S25), in S26, the control device 23 controls the bidirectional converter 8 according to the DR reduction instruction to perform a discharge operation of supplying the power stored in the power storage device 130 to the load 120 (see Figure 5 ).

[0105] During the execution of the DR reduction, in S27, the control device 23 determines whether the DR reduction period has ended. If the DR reduction period has not ended (when the determination in S27 is No), in S28, the control device 23 determines whether the SOC of the power storage device 130 has fallen below SOCbackup. If the SOC exceeds SOCbackup (when the determination in S28 is No), the process returns to S27. On the other hand, if the SOC falls below SOCbackup (when the determination in S28 is Yes), the process proceeds to S29, and the control device 23 sends a DR impossibility signal to the aggregator server 210.

[0106] When a DR disabled signal is transmitted in S29 or the DR reduction period ends (YES in S27 ), control device 23 stops the operation of bidirectional converter 8 in S30 , thereby stopping the discharge of power storage device 130 .

[0107] During the DR reduction, the aggregator server 210 determines in S07 whether a DR disallowed signal is received from the control device 23. If no DR disallowed signal is received (No in S07), the aggregator server 210 determines in S08 whether the DR reduction period has ended.

[0108] When receiving a DR impossible signal (when it is determined as YES in S07 ) or when the DR reduction period ends (when it is determined as YES in S08 ), the aggregator server 210 ends the execution of DR reduction in S09 .

[0109] In MPC110, the control device 23 is Fig.10 S37 determines whether a power outage has occurred in the power system 200. If the AC voltage VI supplied from the power system 200 is lower than the lower limit value, S37 determines yes. On the other hand, if the AC voltage VI is higher than the lower limit value, S37 determines no.

[0110] When the power system 200 is healthy (when the determination in S37 is NO), in S41, the control device 23 controls the bidirectional converter 8 to charge the power storage device 130 (see Figure 3During charging, in S42, the control device 23 determines whether the SOC of the power storage device 130 is 100% or more. If the SOC is 100% or more (if it is determined to be YES in S42), in S43, the control device 23 stops the operation of the bidirectional converter 8, thereby stopping the discharge of the power storage device 130.

[0111] Returning to S37, when a power outage occurs in the power system 200 (if it is determined to be YES in S37), in S38, the control device 23 controls the bidirectional converter 8 to perform a discharge operation of the power storage device 130 (see Figure 4 During discharge, in S39, the control device 23 determines whether the SOC of the power storage device 130 is less than or equal to SOCmin. When the SOC is less than or equal to SOCmin (if it is determined to be YES in S39), in S40, the control device 23 stops the operation of the bidirectional converter 8, thereby stopping the discharge of the power storage device 130.

[0112] Return to S05, and if it is not the start time of the DR reduction period (if the determination in S05 is No), proceed to Fig.10 In S10, the aggregator server 210 determines whether it is the start time of the DR period to be increased. If it is not the start time of the DR period to be increased (when it is determined to be No in S10), the process returns to S05.

[0113] After the DR notice signal is transmitted, when the time for increasing the DR period comes to start (when it is determined as YES in S10 ), in S11 , the aggregator server 210 transmits a DR increase instruction to the demand side 100 .

[0114] In the MPC 110, when the DR increase instruction is received from the aggregator server 210 (if it is determined to be YES in S31), in S32, the control device 23 controls the bidirectional converter 8 to perform the charging operation of the power storage device 130 (see Figure 7 ).

[0115] During the execution of the DR increase, the control device 23 determines in S33 whether the DR increase period has ended. If the DR increase period has not ended (if the determination is No in S33), the control device 23 determines in S34 whether the SOC of the power storage device 130 is greater than or equal to SOCmax. If the SOC is less than SOCmax (if the determination is No in S34), the process returns to S33. If the SOC is greater than or equal to SOCmax (if the determination is Yes in S34), the control device 23 sends a DR impossibility signal to the aggregator server 210 in S35.

[0116] When a DR disabled signal is sent in S35 or the DR enhancement period ends (YES in S33 ), control device 23 stops the operation of bidirectional converter 8 in S36 , thereby stopping the discharge of power storage device 130 .

[0117] During the execution of DR enhancement, the aggregator server 210 determines in S12 whether a DR disabled signal is received from the control device 23. If no DR disabled signal is received (No in S12), the aggregator server 210 determines in S13 whether the DR enhancement period has ended.

[0118] When receiving a DR impossible signal (when it is determined as YES in S12 ) or when it is the end time of the DR increase period (when it is determined as YES in S13 ), the aggregator server 210 ends the execution of DR increase in S14 .

[0119] As described above, according to the power supply device of the present embodiment, it is possible to contribute to the supply and demand adjustment of the power system 200 requested by the power company while ensuring power failure compensation for the load 120 .

[0120] In addition, in the above-mentioned embodiment, the MPC 110 is described as one form of the power supply device of the present embodiment, but the power supply device is not limited to the MPC 11, and may be a UPS. Fig.11 FIG. 2 is a diagram showing a configuration of a power supply device according to a modified example of the present embodiment. Fig.11 In the present invention, UPS is described as another type of power supply device.

[0121] like Fig.11 As shown, UPS150 and Figure 1 The MPC 110 shown is different in that it includes a converter 31, an inverter 33, and a bidirectional chopper 32 instead of VCB 1, 5, 21, HSS 2, and power converter 7. In addition, the UPS 150 receives a three-phase AC voltage from the power system 200 and supplies the three-phase AC voltage to the load 120, but in order to simplify the drawings and descriptions, Fig.11 Only one phase of the circuit is shown.

[0122] The converter 31 has an AC terminal 31a, a positive voltage terminal 31b, and a negative voltage terminal 31c. The bidirectional chopper 32 has a DC terminal 32a, a positive voltage terminal 32b, and a negative voltage terminal 32c. The inverter 33 has an AC terminal 33a, a positive voltage terminal 33b, and a negative voltage terminal 33c.

[0123] The AC terminal 31a of the converter 31 is connected to the input terminal T1. The current detector 13 detects the instantaneous value of the current Ii flowing between the input terminal T1 and the AC terminal 1a, and sends a signal Iif indicating the detected value to the control device 23.

[0124] The DC terminal 32a of the bidirectional chopper 32 is connected to the DC terminal T3. The current detector 15 detects the instantaneous value of the DC current IB flowing between the DC terminal T2 and the DC terminal 2a, and sends a signal IBf indicating the detected value to the control device 23.

[0125] The AC terminal 33a of the inverter 33 is connected to the output terminal T2. The current detector 14 detects the instantaneous value of the current Io flowing between the AC terminal 34a and the output terminal T2, and sends a signal Iof indicating the detected value to the control device 23.

[0126] One terminal of the DC lines L1 and L2 is connected to the positive voltage terminal 31b and the negative voltage terminal 31c of the converter 31. The other terminals of the DC lines L1 and L2 are connected to the positive voltage terminal 33b and the negative voltage terminal 33c of the inverter 33. In addition, the DC lines L1 and L2 are connected to the positive voltage terminal 32a and the negative voltage terminal 32c of the bidirectional chopper 32, respectively.

[0127] The capacitor C1 is connected between the DC lines L1 and L2 to stabilize and smooth the DC voltage VD between the DC lines L1 and L2. The instantaneous value of the DC voltage VD is detected by the control device 23.

[0128] The converter 31 is controlled by the control device 23, and when the power system 200 is healthy, the AC voltage VI supplied from the power system 200 via the input terminal T1 is converted into a DC voltage VD, and outputted between the DC lines L1 and L2. When the power system 200 is out of power, the operation of the converter 31 is stopped. When the power system 200 is healthy, the control device 23 controls the converter 31 so that the DC voltage VD between the DC lines L1 and L2 becomes the reference voltage VDr. The converter 31 corresponds to an embodiment of the "second power converter".

[0129] The bidirectional chopper 32 is controlled by the control device 23. When the power system 200 is healthy, the bidirectional chopper 32 stores the DC power supplied from the converter 31 via the DC lines L1 and L2 in the power storage device 130. When the power system 200 is out of power, the bidirectional chopper 32 converts the DC voltage VB of the power storage device 130 into a DC voltage VD, and outputs it between the positive voltage terminal 32b and the negative voltage terminal 32c. The bidirectional chopper 32 is configured to selectively perform a charging operation for storing DC power in the power storage device 130 and a discharging operation for outputting the DC power of the power storage device 130 between the DC lines L1 and L2. The bidirectional chopper 32 corresponds to an embodiment of the “first power converter”.

[0130] When the power system 200 is healthy, the control device 23 controls the bidirectional chopper 32 so that the DC voltage VB becomes the reference DC voltage VBr. The reference DC voltage VBr is set based on the OCV when the power storage device 130 is in a fully charged state (SOC=100%) in the OCV-SOC curve of the power storage device 130. When the power system 200 is out of power, the control device 23 controls the bidirectional chopper 32 so that the DC voltage VD becomes the reference voltage VDr.

[0131] The inverter 33 is controlled by the control device 23. When the power system 200 is healthy, the inverter 33 converts the DC voltage VD supplied from the converter 31 via the DC lines L1 and L2 into the AC voltage VO, and supplies it to the load 120. When the power system 200 is out of power, the inverter 33 converts the DC voltage VD supplied from the power storage device 130 via the bidirectional chopper 32 and the DC lines L1 and L2 into the AC voltage VO, and supplies it to the load 120. The output voltage VO of the inverter 33 can be controlled to a desired value. The control device 23 controls the inverter 33 so that the AC output voltage VO becomes the reference AC voltage VOr. The inverter 33 corresponds to an embodiment of the "third power converter".

[0132] The control device 23 controls the entire UPS 150 based on the AC voltage VI, the AC current Ii, the DC voltages VD and VB, the DC current IB, the AC voltage VO, the AC current Io, a signal from the operation unit 22, and the like.

[0133] When the power system 200 is healthy, when a DR notice signal is received from the aggregator server 210, the control device 23 controls the bidirectional chopper 32 so that the total power of the AC power supplied from the power system 200 via the converter 31 and the inverter 33 and the AC power supplied from the power storage device 130 via the bidirectional chopper 32 and the inverter 33 is supplied to the load 120. When the SOC of the power storage device 130 decreases to SOCwait, the control device 23 stops the discharge of the power storage device 130. That is, the control device 23 discharges the power storage device 130 while ensuring the power storage amount for power outage compensation before the start of DR. Thereby, when DR is to increase DR, the power storage device 130 can receive a part of the power supplied from the power system 200 during the execution of DR.

[0134] After receiving the DR notice signal, when receiving the DR reduction instruction from the aggregator server 210, the control device 23 controls the bidirectional chopper 32 so that the total power of the AC power supplied from the power system 200 via the converter 31 and the inverter 33 and the AC power supplied from the power storage device 130 via the bidirectional chopper 32 and the inverter 33 is supplied to the load 120. As a result, the AC power supplied from the power system 200 to the demand side 100 can be reduced, so it can contribute to the suppression of the demand amount of power requested by the power company of the demand side 100. However, when the SOC of the power storage device 130 decreases to less than SOCbackup, the control device 23 sends a DR non-permitted signal to the aggregator server 210, thereby ensuring the power storage amount of the power storage device 130 for power outage compensation.

[0135] After receiving the DR notice signal, when receiving the DR increase instruction from the aggregator server 210, the control device 23 controls the bidirectional chopper 32 to perform a charging operation to store DC power in the power storage device 130. As a result, the AC power supplied from the power system 200 to the demand side 100 can be increased, so the demand side 100 can contribute to the increase in the demand for power requested by the power company. In addition, by discharging the power storage device 130 while ensuring the power storage amount for power outage compensation in response to the DR notice signal, the power storage device 130 can receive a part of the power supplied from the power system 200 during the execution of the DR increase.

[0136] The embodiments disclosed this time should be considered as illustrative in all aspects and not restrictive. The scope of the present invention is indicated by the claims, and it is intended to include all modifications within the meaning and scope equivalent to the claims.

[0137] Description of Reference Numerals

[0138] 1, 5, 6, 21: VCB, 2: high-speed switch, 7: power converter, 8: bidirectional converter, 10, 13-15: current detector, 11: reactor, 12, C1: capacitor, 20: transformer, 22: operation unit, 23, 212: control device, 31: converter, 32: bidirectional chopper, 33: inverter, 100: demand side, 110: MPC, 120: load, 130 load storage device, 140, 216: communication device, 150: UPS, 200: power system, 210: aggregator server, 214: storage device, 230: CPU, 232: memory, 234: I / O circuit, T1: input terminal, T2: output terminal, T3: DC terminal, L1, L2: DC line.

Claims

1. A power supply device connected between a power system and a load, supplying a first AC power supplied from the power system to the load when the power system is healthy, and supplying a second AC power to the load when the power system is out of power, comprising: a first power converter configured to selectively perform a charging operation of converting a portion of the first AC power into DC power and storing the converted power in a power storage device, and a discharging operation of converting the DC power of the power storage device into the second AC power; and A control device is communicatively connected to a server for adjusting the supply and demand of electricity in the power system, When the power system is out of power, the control device is: controlling the discharge operation in the first power converter so that the second AC power is supplied to the load, The power storage device is provided with an SOC reference value and a standby SOC greater than the SOC reference value, wherein the SOC reference value is greater than or equal to the SOC required for the power storage device to supply the second AC power to the load until a predetermined compensation time has passed since a power outage occurred in the power system, When the power system is sound, the control device is: controlling the charging operation in the first power converter so that the power storage device is in a fully charged state, When a demand response forecast signal for adjusting the demand amount in the power system is received from the server, controlling the discharge operation in the first power converter so that a total of the first AC power and the second AC power is supplied to the load, stopping the discharging operation in response to the SOC of the power storage device decreasing to the standby SOC, The discharging action or the charging action in the first power converter is controlled according to the demand response instruction received from the server.

2. The power supply device according to claim 1, wherein: After receiving the advance signal, when receiving a demand reduction response instruction to reduce the demand in the power system from the server, the control device is: controlling the discharge operation in the first power converter so that a total of the first AC power and the second AC power is supplied to the load, The discharging operation is stopped in response to the SOC of the power storage device decreasing to the SOC reference value.

3. The power supply device according to claim 2, wherein: In case the demand reduction response instruction is received from the server, the control device is: In response to the SOC of the power storage device decreasing to the SOC reference value, a demand response impossible signal is transmitted to the server.

4. The power supply device according to claim 1, wherein: After receiving the advance signal, when receiving a demand response enhancement instruction to increase the demand in the power system from the server, the control device is: controlling the charging operation in the first power converter, The charging operation is stopped in response to the SOC of the power storage device reaching an upper limit SOC value that is smaller than that in the fully charged state.

5. The power supply device according to claim 4, wherein: In case the demand-increasing response instruction is received from the server, the control device is: In response to the SOC of the power storage device reaching the SOC upper limit value, a demand response impossible signal is transmitted to the server.

6. The power supply device according to claim 4, wherein: The control device is configured to switch the charging operation of the power storage device from constant current charging to constant voltage charging according to the SOC of the power storage device, The SOC upper limit value is set based on the SOC when switching from the constant current charging to the constant voltage charging.

7. The power supply device according to any one of claims 1 to 6, wherein: The power supply device further includes a switch having a first terminal connected to the power system and a second terminal connected to the load. The control device is configured to turn on the switch when the power system is healthy, and to turn off the switch when the power system is out of power. The first power converter is connected between the second terminal and the power storage device.

8. The power supply device according to any one of claims 1 to 6, wherein: The power supply device further comprises: a second power converter, which converts the first AC power into DC power and supplies it to the DC line when the power system is healthy, and stops operating when the power system fails; as well as The third power converter converts the DC power received from the DC line into a third AC power and supplies the third AC power to the load. The first power converter is connected between the DC line and the power storage device.

9. The power supply device according to any one of claims 1 to 6, wherein: The power storage device is a lithium-ion battery.

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