Power supply system

Abstract

In the power supply system, the control device is configured to adjust the SOC of each of the AC battery string and the DC battery string through exchange of electric power between the AC battery string and the DC battery string before performing the required energy management.

Description

Technical Field

[0001] This disclosure relates to power systems, and more particularly to power systems using multiple battery strings. Background Technology

[0002] Japanese Patent Application Publication No. 2018-074709 discloses a control circuit for controlling a battery string. The battery string includes multiple battery circuit modules interconnected. Each battery circuit module in the battery string includes a battery, a first switch connected in parallel with the battery, a second switch connected in series with the battery, and a first output terminal and a second output terminal to which the battery voltage is applied when the first switch is in an off state and the second switch is in a conducting state. By controlling the first and second switches of each battery circuit module in the battery string, the control circuit can adjust the output voltage of the battery string to a desired level. Summary of the Invention

[0003] Japanese Patent Application Publication No. 2018-074709 discloses a power supply system that uses the battery string described above to output DC power. However, Japanese Patent Application Publication No. 2018-074709 does not conduct any research on the power waveform (AC power) output using the battery string. Furthermore, Japanese Patent Application Publication No. 2018-074709 also does not conduct any research on energy management using the battery string.

[0004] This disclosure provides a power system capable of using battery strings for appropriate energy management.

[0005] The power system disclosed herein includes a first power supply circuit, a second power supply circuit, and a control device. The first power supply circuit includes a DC battery string for direct current (DC) power and a converter for converting the DC power output from the DC battery string into alternating current (AC) power, configured to output first AC power using the DC battery string and the converter. The second power supply circuit includes an AC battery string for alternating current (AC) power, configured to output second AC power using the AC battery string. The control device is configured to control the first and second power supply circuits. The AC and DC battery strings are configured to exchange power with each other. Each of the AC and DC battery strings includes multiple battery circuit modules connected in series. Each of the multiple battery circuit modules includes a battery, an output terminal for outputting the battery voltage, a first switch connected to the output terminal and in parallel with the battery, and a second switch connected in series with the battery, configured such that when the first switch is in an off state and the second switch is in an on state, the battery voltage is applied to the output terminal. The control device is configured to adjust the SOC (State of Charge) of the AC and DC battery strings respectively by exchanging power between the AC and DC battery strings before performing the required energy management.

[0006] The aforementioned power supply system can easily output various types of AC power using the first and second power supply circuits. Specifically, the first power supply circuit can use a converter to generate a power waveform (AC power) based on the DC power output from the DC battery string. The second power supply circuit can adjust the number of batteries connected to the circuit by controlling the first and second switches of each battery circuit module included in the AC battery string. Furthermore, different types of batteries (e.g., high-capacity batteries / high-output batteries) can be used in the AC and DC battery strings. Therefore, according to the above structure, it becomes easy to expand the output voltage range (V) and power range (kW) or extend the output time in the design of the power supply system. Thus, the aforementioned power supply system has a structure that easily responds to various energy management requirements.

[0007] Furthermore, in the aforementioned power system, the state of charge (SOC) of both the AC and DC battery strings is adjusted before performing the required energy management. This ensures that both the AC and DC battery strings are in a state compliant with the required energy management, making it easier to respond to the requested energy management. Additionally, since SOC adjustment is performed through power exchange between the AC and DC battery strings, SOC adjustment can be performed without relying on an external power supply.

[0008] The aforementioned control device can be configured such that, when the required energy management is AC power output and the required output power is less than a first reference value, power is supplied from the DC battery string to the AC battery string in such a way that the SOC of the AC battery string becomes greater than or equal to the first SOC value, and after the SOC of the AC battery string becomes greater than or equal to the first SOC value, the required AC power is output from the second power supply circuit.

[0009] According to the above structure, the second power supply circuit can easily perform a small AC power output as required (the output power is smaller than the first reference value). In the above structure, the AC battery string receives power from the DC battery string before performing the required AC power output. Therefore, sufficient state of charge (SOC) for energy management (discharge) can be easily ensured in the AC battery string.

[0010] The aforementioned control device can be configured such that, when the required energy management is AC power output and the required output power is greater than a first reference value, after adjusting the respective SOC of the AC battery string and DC battery string in a manner that enables the first power supply circuit and the second power supply circuit to simultaneously output AC power for a period of time greater than a first time, the required AC power is output from the first power supply circuit and the second power supply circuit.

[0011] Based on the above structure, the first and second power supply circuits can easily execute the required large-capacity AC power output (AC power output greater than the first reference value). In this structure, the SOC of the AC and DC battery strings is adjusted before executing the required AC power output. The SOC of the AC and DC battery strings is adjusted in a balanced manner to sufficiently extend the time during which the first and second power supply circuits can simultaneously output AC power (first AC power and second AC power). For example, the target SOC of each AC and DC battery string can be determined by considering the power consumption per unit time of each battery string during energy management execution. Therefore, long-term energy management (large-capacity AC power output) can be easily executed.

[0012] The aforementioned control device can be configured to determine a first SOC value and a first time based on the period of the requested AC power output. By performing the aforementioned SOC adjustment based on the determined first SOC value and first time, the power supply system can easily continue the requested AC power output during the requested period.

[0013] The control device described above can be configured such that, when the required energy management is AC power input and the required input power is less than a second reference value, power is supplied from the AC battery string to the DC battery string in such a way that the SOC of the AC battery string becomes less than or equal to the second SOC value, and after the SOC of the AC battery string becomes less than or equal to the second SOC value, the required AC power is input to the second power supply circuit.

[0014] According to the above structure, the second power supply circuit can easily perform a small AC power input as required (the input power is smaller than the second reference value). In the above structure, the power output from the AC battery string is input to the DC battery string before performing the required AC power input. Therefore, sufficient capacity (idle capacity) for energy management (charging) is easily ensured in the AC battery string.

[0015] The aforementioned control device can be configured such that, when the required energy management is AC power input and the required input power is greater than a second reference value, after adjusting the respective SOC of the AC battery string and DC battery string in such a way that the time for simultaneously inputting AC power to the first power circuit and the second power circuit is a second time or more, the required AC power is input to the first power circuit and the second power circuit.

[0016] According to the above structure, the first and second power supply circuits can easily execute the required large AC power input (AC power input greater than the second reference value). In this structure, the SOC of the AC and DC battery strings is adjusted before executing the required AC power input. The SOC of the AC and DC battery strings is adjusted in a balanced manner to sufficiently extend the time for simultaneously inputting AC power to the first and second power supply circuits. For example, the target SOC of each AC and DC battery string can be determined by considering the energy storage capacity of each battery string per unit time during energy management execution. Therefore, long-term energy management (large AC power input) can be easily executed.

[0017] The aforementioned control device can be configured to determine a second SOC value and a second time based on the period of the required AC power input. By performing the aforementioned SOC adjustment based on the determined second SOC value and second time, the power system can easily continue the required AC power input during the required period.

[0018] The power density of batteries in a DC battery string can be higher than that of batteries in an AC battery string. Furthermore, the energy density of batteries in an AC battery string can be higher than that of batteries in a DC battery string.

[0019] Based on the above structure, various types of AC power can be output using the first power supply circuit and the second power supply circuit. For example, by using a high-capacity battery (a battery with high energy density), long-term power supply can be easily achieved. In addition, by using a high-output battery (a battery with high power density), high-speed power supply can be easily achieved.

[0020] Hereinafter, each battery in a DC battery string will also be referred to as a "DC battery". The power density of a DC battery can be above 1000W / kg, above 1500W / kg but less than 5000W / kg, or above 5000W / kg. The energy density of a DC battery can be less than 300Wh / kg, less than 100Wh / kg, or above 50Wh / kg but less than 500Wh / kg.

[0021] Hereinafter, each battery in an AC battery string will also be referred to as an "AC battery". The energy density of an AC battery can be above 300Wh / kg, above 500Wh / kg but less than 1000Wh / kg, or above 1000Wh / kg. The power density of an AC battery can be less than 1000W / kg, or above 300W / kg but less than 1000W / kg.

[0022] In any of the aforementioned power supply systems, the first power supply circuit and the second power supply circuit can each be electrically connected to an external power source that will supply power to the building and to the electrical wiring connecting the building. The aforementioned energy management can be power regulation of the external power source.

[0023] According to the above structure, AC power can be supplied to the building from both the first and second power supply circuits. Furthermore, since power from an external power source can be used to charge the AC and DC batteries, each of the first and second power supply circuits can store power as needed. This power system can function as an emergency power source for the building. The external power source can be an electrical system.

[0024] Any of the aforementioned power systems may further include an insulation filter disposed between the first power circuit and the aforementioned wires. The converter may be a reused product that has been used for other purposes.

[0025] In a system where the converter is a reused component, the desired AC power waveform may not be obtained using the converter. Therefore, in the above structure, an insulation filter is provided between the first power supply circuit and the aforementioned wires. With such an insulation filter, the desired AC power waveform can be easily obtained, and the noise contained in the output (AC power) of the first power supply circuit can be easily reduced.

[0026] For example, a reusable component (i.e., a converter removed from the xEV after use) that can be used as a driving converter in an electric vehicle (hereinafter also referred to as "xEV") can be used as the aforementioned converter. A driving converter is, for example, a converter that drives a driving electric motor in an xEV. An xEV is a vehicle that uses electricity as its power source, either entirely or partially. xEVs include BEVs (battery electric vehicles), PHEVs (plug-in hybrid electric vehicles), and FCEVs (fuel cell electric vehicles).

[0027] The first power supply circuit may include: a first driving circuit for driving a first switch and a second switch included in a DC battery string; and a first control circuit for sending signals to the first driving circuit for driving the first switch and the second switch respectively according to instructions from a control device. The second power supply circuit may include: a second driving circuit for driving the first switch and the second switch included in an AC battery string; and a second control circuit for sending signals to the second driving circuit for driving the first switch and the second switch respectively according to instructions from a control device.

[0028] Based on the above structure, the AC battery string and the DC battery string can be properly controlled by the first control circuit and the second control circuit.

[0029] In the aforementioned power system, the converter can be a three-phase converter. The control device can be configured to send commands for controlling the DC battery strings to a first control circuit and control the converter, in a manner that outputs three-phase AC power from a first power supply circuit. The AC battery strings can include a U-phase battery string, a V-phase battery string, and a W-phase battery string that are Y-connected. The control device can be configured to send commands for controlling the U-phase battery string, the V-phase battery string, and the W-phase battery string to a second control circuit, in a manner that outputs three-phase AC power from a second power supply circuit.

[0030] Based on the above structure, three-phase AC power can be output from both the first power supply circuit and the second power supply circuit. The voltage of the three-phase AC power can be above 190V and below 300V, or it can be 200V.

[0031] According to the above-described scheme of this disclosure, a power system capable of using battery strings for appropriate energy management can be provided. Attached Figure Description

[0032] The features, advantages, and technical and industrial significance of exemplary embodiments of the present invention will be described below with reference to the accompanying drawings, in which the same reference numerals denote the same elements, wherein:

[0033] Figure 1 This is a diagram illustrating the structure of a power supply system according to an embodiment of the present disclosure.

[0034] Figure 2 It is shown Figure 1 The diagram shows the structure of each scanning unit in the power supply system.

[0035] Figure 3 Is Figure 2 The scan unit shown is a timeline illustrating an example of the operation of a battery circuit module controlled by a gate signal.

[0036] Figure 4 Is Figure 2 The diagram shown illustrates the battery circuit module in its operational state within the scanning unit.

[0037] Figure 5 Is Figure 2 The scan unit shown illustrates the state of the battery circuit module during the delay period.

[0038] Figure 6 Is Figure 2 The scan unit shown illustrates the state of the battery circuit module during the stop period.

[0039] Figure 7 It is used for in Figure 2 The diagram illustrates an example of scan control performed in the scan unit shown.

[0040] Figure 8 It is shown Figure 1 A diagram showing the detailed structure of the converter.

[0041] Figure 9 This is a diagram showing the structure of the second power supply circuit.

[0042] Figure 10 It is shown Figure 1 A diagram showing the detailed structure of the switching device.

[0043] Figure 11 It is shown Figure 10 A diagram illustrating an example of the operation of the switching device.

[0044] Figure 12 Is Figure 1 The flowchart shown illustrates an example of the processing performed by the GCU (control unit) in a remotely powered-on state in the power system.

[0045] Figure 13 It is shown Figure 12 The flowchart shows the details of the SOC adjustment.

[0046] Figure 14 It is shown in Figure 1 The flowchart shown is an example of the processing performed by the GCU (control unit) when it performs power adjustment according to a prescribed charging and discharging plan. Detailed Implementation

[0047] Hereinafter, embodiments of this disclosure will be described with reference to the accompanying drawings. Figure 1 The following is a detailed explanation. It should be noted that the same or similar parts in the diagram will be labeled with the same reference numerals without repeated explanations. Hereinafter, the String Control Unit (SCU) will be referred to as "SCU," and the Group Control Unit (GCU) as "GCU." Additionally, alternating current (AC) is sometimes referred to as "AC," and direct current (DC) as "DC."

[0048] Figure 1This diagram illustrates the structure of the power supply system according to this embodiment. The power supply system 1 includes a first power supply circuit 2, a second power supply circuit 3, insulation filters T1 and T2, relays R1 and R2, a distribution board C1, a switching device C3, and a GCU 100. The GCU 100 corresponds to an example of the "control device" of this disclosure. The GCU 100 can be a computer. The GCU 100 includes, for example, a processor, RAM (Random Access Memory), and a storage device (none shown). Various processes are performed by executing programs stored in the storage device through the processor. However, the various processes in the GCU 100 are not limited to software-based execution; they can also be performed using dedicated hardware (electronic circuits). In this embodiment, the power supply system 1 is applied to a building 300 such as a residence, school, hospital, commercial facility, or station.

[0049] The power system PG supplies electricity to building 300 via power lines PGL. The power system PG is a power grid constructed from transmission and distribution equipment. Multiple power plants are connected to the power system PG. The power system PG receives power from these power plants. In this embodiment, the power company maintains and manages the power system PG (commercial power source). The power company is equivalent to the TSO (System Operator). The power system PG supplies three-phase AC power to building 300. The power system PG is equivalent to an example of the "external power source" of this disclosure. The supply and demand status of the power system PG is managed by server 200. Server 200 is configured to communicate with GCU 100. In this embodiment, server 200 belongs to the power company. However, it is not limited to this; server 200 may also be a server belonging to an integrator, or a server that trades in the electricity market (e.g., a supply and demand adjustment market).

[0050] The first power supply circuit 2 and the second power supply circuit 3 are each configured to receive and transmit power to the power system PG. The first power supply circuit 2 and the second power supply circuit 3 sometimes receive power from the power system PG and sometimes supply power to the power system PG. The first power supply circuit 2 and the second power supply circuit 3 are each electrically connected to the wire PGL (the wire connecting the power system PG and the building 300) via the distribution board C1. However, a relay R1 and an insulation filter T1 are installed between the wire PGL and the first power supply circuit 2 (more specifically, between the distribution board C1 and the first power supply circuit 2). Additionally, a relay R2 and an insulation filter T2 are installed between the wire PGL and the second power supply circuit 3 (more specifically, between the distribution board C1 and the second power supply circuit 3).

[0051] The distribution board C1 is equipped with a residual current device (RCD) and / or a circuit breaker. Additionally, power sensors C1a and C1b are installed on the distribution board C1. Power sensor C1a includes a current sensor that detects the current (input / output current) flowing between the first power circuit 2 and the wire PGL, and a voltage sensor that detects the input / output voltage of the first power circuit 2. Power sensor C1b includes a current sensor that detects the current (input / output current) flowing between the second power circuit 3 and the wire PGL, and a voltage sensor that detects the input / output voltage of the second power circuit 3. The detection results of power sensors C1a and C1b are output to the GCU100. The distribution board C1 may also include an electric force meter (not shown).

[0052] The distribution board C2, installed within building 300, is configured to receive power from both the power system PG and the power supply system 1. The distribution board C2 is connected to the building wiring and distributes power supplied from at least one of the power system PG and the power supply system 1 to the building wiring.

[0053] The first power supply circuit 2 includes battery strings St1, St2, and St3, converters 11, 21, and 31, and SCUs 12, 22, and 32. The second power supply circuit 3 includes battery strings St4 to St9 and SCUs 41 to 46. The battery strings in the first power supply circuit 2 and the second power supply circuit 3 constitute a scanning unit SU.

[0054] Figure 2 This is a diagram showing the structure of the scanning unit SU. (and...) Figure 1 Refer to together Figure 2 In the power system 1 of this embodiment, the battery string St (equivalent to Figure 1 The battery strings St1 to St9 shown, and the multiple drive circuits SUA that drive the switches (SW51 and SW52 described later) within the battery string St. Figure 1 (not shown in the diagram) and the SCU (equivalent to) that sends control signals to the drive circuit SUA. Figure 1 The SCUs 12, 22, 32, and 41-46 shown are modular scanning units SU mounted on the first power supply circuit 2 and the second power supply circuit 3, respectively. It should be noted that multiple drive circuits SUA can also be integrated onto a single substrate. Alternatively, the scanning unit SU can also be a single circuit board.

[0055] The battery string St has multiple battery circuit modules M connected in series. In this embodiment, the battery string St contains approximately 20 battery circuit modules M, but this number is arbitrary and can be 5 to 50, or even more than 100. In this embodiment, each battery string in the first power circuit 2 and the second power circuit 3 contains the same number of battery circuit modules M, but the number of battery circuit modules M may differ for each battery string.

[0056] Each battery circuit module M includes a power circuit SUB and a housing Cg. Housing Cg contains a battery B and a monitoring unit BS. The power circuit SUB and battery B are connected to form a battery circuit module M containing battery B. A drive circuit SUA is provided for each battery circuit module M. Furthermore, the drive circuit SUA is configured to drive the switches (more specifically, SW51 and SW52, described later) included in the battery circuit module M. Details regarding battery B will be described later. In this embodiment, different types of batteries are used in the first power circuit 2 and the second power circuit 3.

[0057] like Figure 2 As shown, each battery circuit module M also includes cut-off devices RB1 and RB2 (hereinafter referred to as "cut-off devices RB" without distinction). The power circuit SUB and the cartridge Cg are interconnected via cut-off devices RB1 and RB2. The SCU is configured to switch the connection state (on / off) between the power circuit SUB and the cartridge Cg by controlling the on / off state of each cut-off device RB according to control commands from the GCU100. The cut-off device RB can be an electromagnetic mechanical relay. The cut-off device RB can also be configured to be manually on / off by the user.

[0058] In this embodiment, the box Cg is configured to be detachable from the power circuit SUB. For example, the user can remove the box Cg from the power circuit SUB even when the cutters RB1 and RB2 are both in the open state (off state). The battery string St can operate even with empty boxes, so the user can easily increase or decrease the number of boxes Cg contained in the battery string St. Such a battery string St is suitable for battery reuse.

[0059] In the housing Cg, the monitoring unit BS is configured to detect the state of battery B (e.g., voltage, current, and temperature) and output the detection results to the SCU. The monitoring unit BS includes a voltage sensor for detecting the voltage of battery B, a current sensor for detecting the current of battery B, and a temperature sensor for detecting the temperature of battery B. Alternatively, the monitoring unit BS may also be a BMS (Battery Management System) with SOC estimation, SOH (State of Health) estimation, battery voltage equalization, diagnostic functions, and communication functions, in addition to the aforementioned sensor functions. The SCU obtains the state of each battery B (e.g., temperature, current, voltage, SOC, and internal resistance) based on the output of each monitoring unit BS and outputs the obtained state of each battery B to the GCU100. It should be noted that SOC (State Of Charge) represents the remaining charge capacity, for example, expressed as the ratio of the current charge capacity to the charge capacity at full charge, ranging from 0% to 100%.

[0060] The battery circuit modules M contained in the battery string St are connected by a common wire PL. The wire PL contains the output terminals OT1 and OT2 of each battery circuit module M. The battery circuit modules M contained in the battery string St are connected to each other through the output terminal OT2 of the battery circuit module M and the output terminal OT1 of the adjacent battery circuit module M.

[0061] The power circuit SUB includes a first switching element 51 (hereinafter referred to as "SW51"), a second switching element 52 (hereinafter referred to as "SW52"), a first diode 53, a second diode 54, a choke coil 55, a capacitor 56, and output terminals OT1 and OT2. Each of SW51 and SW52 is driven by a drive circuit SUB. In this embodiment, SW51 and SW52 correspond to examples of the "first switch" and "second switch" of this disclosure, respectively.

[0062] A SW51, a capacitor 56, and a battery B are connected in parallel between the output terminals OT1 and OT2 of the power circuit SUB. SW51 is located on wire PL and is configured to switch the connection state (on / off) between output terminals OT1 and OT2. Output terminal OT1 is connected to the positive terminal of battery B via wire BL1, and output terminal OT2 is connected to the negative terminal of battery B via wire BL2. Cut-off devices RB1 and RB2 are respectively located on wires BL1 and BL2. SW52 and a choke coil 55 are also located on wire BL1. In the battery circuit module M, when SW52, connected in series with battery B, is in the on state (conducting state) and SW51, connected in parallel with battery B, is in the off state (disconnecting state), the voltage of battery B is applied between output terminals OT1 and OT2.

[0063] A capacitor 56 is provided between the output terminals OT1 and OT2 and the battery B, and is connected to wires BL1 and BL2 respectively. One end of the capacitor 56 is connected to wire BL1 between SW52 and choke coil 55. The capacitor 56 smooths the voltage of the battery B and outputs it between the output terminals OT1 and OT2.

[0064] SW51 and SW52 are each, for example, FETs (Field-Effect Transistors). First diode 53 and second diode 54 are connected in parallel with respect to SW51 and SW52, respectively. SW52 is located between the output terminal OT1 and the choke coil 55. The choke coil 55 is located between SW52 and the positive terminal of battery B. Battery B, choke coil 55, and capacitor 56 form an RLC filter. This RLC filter aims to average the current. It should be noted that SW51 and SW52 are not limited to FETs; they can also be switches other than FETs.

[0065] The SCU sends signals to the drive circuit SUA to drive SW51 and SW52 according to instructions from GCU100. Specifically, the SCU generates a gate signal according to control instructions from GCU100. This gate signal is equivalent to the signal used to drive SW51 and SW52 according to instructions from GCU100. The SCU then sends the gate signal to the drive circuit SUA. The drive circuit SUA includes a GD (gate driver) 81 that drives SW51 and SW52 according to the gate signal and a delay circuit 82 that delays the gate signal. The SW51 and SW52 included in the battery circuit module M are each turned on / off according to the gate signal.

[0066] Figure 3 This is a timing diagram illustrating an example of the operation of the battery circuit module M controlled by a gate signal. In this embodiment, a rectangular wave signal is used as the gate signal for driving SW51 (first switch) and SW52 (second switch). Figure 3 The "Low" and "High" gate signals shown represent the L level and H level of the gate signal (rectangular wave signal), respectively. Additionally, "output voltage" refers to the voltage output between output terminals OT1 and OT2.

[0067] In the initial state of battery circuit module M, no gate signal is input to drive circuit SUA (gate signal = L level), and SW51 and SW52 are in the on and off states, respectively. If a gate signal is input to drive circuit SUA, GD81 drives SW51 and SW52 according to the input gate signal. Figure 3In the example shown, at time t1, the gate signal rises from level L to level H, and simultaneously with the rise of the gate signal, SW51 switches from the ON state to the OFF state. Furthermore, at time t2, which is a predetermined time delay (hereinafter referred to as "dt1") from the rise of the gate signal, SW52 switches from the OFF state to the ON state. Thus, the battery circuit module M becomes operational. Hereinafter, the period from the rise of the gate signal to the passage of dt1 will also be referred to as the "first delay period".

[0068] Figure 4 This is a diagram showing the battery circuit module M in its operating state. (Refer to...) Figure 4 In the battery circuit module M in operation, with SW51 in the off state and SW52 in the on state, the voltage of battery B is applied between output terminals OT1 and OT2. The voltage of battery B is applied between output terminals OT1 and OT2 via capacitor 56, and voltage Vm is output between output terminals OT1 and OT2.

[0069] Refer again Figure 3 At time t3, if the gate signal drops from H level to L level, SW52 switches from the ON state to the OFF state simultaneously with the drop in the gate signal. This puts the battery circuit module M into a stopped state. In the stopped state of the battery circuit module M, SW52 is in the OFF state, and the voltage of battery B is no longer applied between output terminals OT1 and OT2. Then, at time t4, which is a predetermined time delay (hereinafter referred to as "dt2") from the drop in the gate signal, SW51 switches from the OFF state to the ON state. dt1 and dt2 can be the same or different. In this embodiment, dt1 and dt2 are each set to 100n seconds. However, dt1 and dt2 can be arbitrarily set.

[0070] Hereinafter, the period from the fall of the gate signal to the passage of dt2 will also be called the "second delay period". In addition, the period from the end of the second delay period to the battery circuit module M entering the working state will also be called the "stop period".

[0071] Figure 5 This is a diagram showing the state of battery circuit module M during the delay period. (Example) Figure 5 As shown, during both the first and second delay periods, SW51 and SW52 are in a disconnected state.

[0072] Figure 6 This is a diagram showing the state of battery circuit module M during the shutdown period. (Example) Figure 6 As shown, during the stop period, SW51 becomes the ON state and SW52 becomes the OFF state, just like in the initial state.

[0073] Regardless of whether it is during the aforementioned delay period or the stop period, the battery circuit module M is in a stopped state. In the stopped state, no voltage is applied between the output terminals OT1 and OT2. By setting the first delay period and the second delay period, it is possible to prevent SW51 and SW52 from simultaneously becoming on (i.e., the battery circuit module M becoming short-circuited).

[0074] The battery string St is configured to output a voltage from 0V up to the sum of the voltages of the individual batteries B within the battery string St. In the scanning unit SU, the scanning control unit (SCU) controls the output voltage of the battery string St by adjusting the number of battery circuit modules M that are simultaneously in operation. In this embodiment, the SCU controls the voltage of the battery string St through scanning control.

[0075] Figure 7 This is a diagram used to illustrate an example of scan control. (and) Figure 2 and Figure 3 Refer to together Figure 7 In the battery string St under scanning control, a specified number (in Figure 7 In the example shown, three batteries B are connected to the circuit, while the other batteries B are disconnected from the circuit. In battery circuit module M, if SW51 is in the off state and SW52 is in the on state, battery B is connected to the circuit, and its voltage is applied to the circuit. In battery circuit module M, if SW51 is in the on state and SW52 is in the off state, battery B is disconnected from the circuit, and its voltage is no longer applied to the circuit (passes through). In the scan control, while swapping the batteries B connected to the circuit, a predetermined number (in...) are maintained. Figure 7 The example shown depicts three batteries (B) simultaneously connected to the circuit. The scanning unit SU, through one side... Figure 3 The gate signal delay shown is used to transmit the gate signal from one end (upstream) of the battery string St to the other end (downstream) to perform scan control. The gate signal is delayed by the delay circuit 82. Furthermore, GD81 drives SW51 and SW52 according to the gate signal. Therefore, the downstream battery B is connected to the circuit later than the upstream battery B. For example, as... Figure 7 As shown, the current and SOC of each battery B in the battery string St are equalized by connecting each battery B in the battery string St sequentially. It should be noted that the delay time of each delay circuit 82 is set by the GCU100. The delay time may be set to 0 (no delay). For example, in the scanning unit SU, if the delay time of all delay circuits 82 is set to 0, then the connection / passing of all batteries B is performed at the same timing.

[0076] The GCU100 can also control the input and output of the battery string St based on the period and duty cycle (the ratio of the H-level period to the period) of the gate signal. The GCU100 can select connection / disconnection for each cell Cg (battery B) in the battery string St. The disconnection instruction is sent from the GCU100 to the SCU. The GD81, which is instructed to disconnect from the SCU, can maintain the corresponding battery B in a through state regardless of the gate signal. Alternatively, the SCU can disconnect a battery B from the circuit by turning off cutters RB1 and RB2. The GCU100 can also adjust the load sharing of each battery B based on its capacity (or SOC). The GCU100 can also prevent the discharge or charging of specific batteries B based on their SOC. For example, the GCU100 can prevent the discharge of batteries B that are likely to be over-discharged, or prevent the charging of batteries B that are likely to be over-charged. Furthermore, the GCU100 can perform constant load-based degradation diagnosis for specified batteries B in the battery string St. The GCU100 can also keep battery B disconnected from the circuit by prohibiting its use (or battery B with severe degradation). (See reference) Figure 6 ).

[0077] Figure 1 The first power supply circuit 2 and the second power supply circuit 3 shown each have a number of the aforementioned scanning units SU corresponding to the number of battery strings. Specifically, the first power supply circuit 2 includes three scanning units SU (hereinafter referred to as "SU1", "SU2", and "SU3") corresponding to battery strings St1 to St3. SCU12, 22, and 32 together with battery strings St1, St2, and St3 respectively constitute SU1, SU2, and SU3. The battery strings, drive circuit, and SCUs of the scanning units SU included in the first power supply circuit 2 are respectively equivalent to an example of the "DC battery string", "first drive circuit", and "first control circuit" of this disclosure. The second power supply circuit 3 includes six scanning units SU (hereinafter referred to as "SU4" to "SU9") corresponding to battery strings St4 to St9. SCU41, 42, 43, 44, 45, and 46 together with battery strings St4, St5, St6, St7, St8, and St9 respectively constitute SU4, SU5, SU6, SU7, SU8, and SU9. The battery string, drive circuit, and SCU of the scanning unit SU included in the second power circuit 3 are respectively equivalent to an example of the "AC battery string", "second drive circuit", and "second control circuit" of this disclosure.

[0078] By controlling SU1 to SU3, GCU100 can enable each of battery strings St1 to St3 to output DC power (constant voltage power) at a desired voltage. GCU100 can determine the output voltage (DC power voltage) of each of battery strings St1 to St3 based on information obtained from the user or server 200. By controlling SU4 to SU9, GCU100 can enable each of battery strings St4 to St9 to output AC power (power with periodically changing voltage magnitude) with a desired voltage waveform. GCU100 can determine the output voltage waveform of each of battery strings St4 to St9 based on information obtained from the user or server 200. The user can also input power supply conditions and / or charging conditions to GCU100.

[0079] In this embodiment, each DC battery (battery B) included in the DC battery strings (battery strings St1, St2, and St3) is a high-output type battery. Specifically, each DC battery is a nickel-metal hydride secondary battery with a power density of 1500 W / kg or more and less than 5000 W / kg and an energy density of 50 Wh / kg or more and less than 500 Wh / kg. Furthermore, each AC battery (battery B) included in the AC battery strings (battery strings St4 to St9) is a high-capacity type battery. Specifically, each AC battery is a lithium-ion secondary battery with a power density of 300 W / kg or more and less than 1000 W / kg and an energy density of 500 Wh / kg or more and less than 1000 Wh / kg. However, different types of lithium-ion secondary batteries are used in battery strings St4, St6, and St8, and battery strings St5, St7, and St9. Each battery B included in battery strings St4, St6, and St8 is a ternary lithium-ion secondary battery (NMC). In addition, each battery B included in battery strings St5, St7 and St9 uses lithium-ion secondary batteries based on iron phosphate (LFP).

[0080] However, the types (e.g., construction and materials) and characteristics (e.g., power density and energy density) of batteries are not limited to those described above and can be appropriately varied. For example, sometimes power-type (high-output) batteries and energy-type (high-capacity) batteries are defined based on a Ragone diagram with power density (W / kg) on ​​the vertical axis and energy density (Wh / kg) on ​​the horizontal axis. Batteries classified as high-output in the Ragone diagram can also be used as DC batteries, and batteries classified as high-capacity in the Ragone diagram can be used as AC batteries. Furthermore, multiple types of rechargeable batteries can be mixed in a single battery string. The battery can also be a lithium-air battery, a lead-acid battery, a NAS (lithium-sulfur) battery, a redox flow battery, or an all-solid-state battery. Additionally, battery B can be manufactured by reusing rechargeable batteries used in xEVs by connecting them in series.

[0081] In the first power supply circuit 2, the DC power output from battery strings St1, St2, and St3 is input to converters 11, 21, and 31, respectively. Hereinafter, [the following will be used...] Figure 1 and Figure 8 The structure of the converter included in the first power supply circuit 2 will now be described. Converters 11, 21, and 31 have the same structure, therefore, the structure of converter 11 will be described as representative below.

[0082] Figure 8 This is a diagram showing the structure of the converter 11 included in the first power supply circuit 2. (And...) Figure 1 Refer to together Figure 8 The converter 11 is a three-phase converter, with switching elements q1 and q2 connected in series in the U-phase arm, switching elements q3 and q4 connected in series in the V-phase arm, and switching elements q5 and q6 connected in series in the W-phase arm. Diodes d1 to d6 are connected in anti-parallel between the collectors and emitters of the switching elements q1 to q6, respectively. In this embodiment, the converter 11 is a three-phase converter previously used to drive a three-phase synchronous motor for xEV. The converter 11 is configured to enable bidirectional power conversion.

[0083] The midpoints of each phase arm of converter 11 are connected to the insulation filter T1, and are also connected to the wire PGL (see reference) via relay R1 and distribution board C1. Figure 1 The switching elements q1 to q6 of converter 11 are controlled by control commands from GCU100. Each switching element of converter 11 is turned on / off, for example, by PWM (Pulse Width Modulation).

[0084] Converter 11 converts the DC power output from battery string St1 into AC power (three-phase AC power) and supplies it to the power line PGL. Converter 11 functions as a DC / AC conversion circuit. The AC power output from converter 11 is supplied to the power line PGL after passing through insulation filter T1, relay R1, and distribution board C1. SU1 can output power from any battery B among the multiple batteries B contained in battery string St1 by controlling SW51 and SW52 of each battery circuit module M contained in battery string St1. For example, SU1 outputs power from a designated battery B to converter 11 according to instructions from GCU100. In SU2 and SU3, power is also output from batteries B contained in battery strings St2 and St3 to converters 21 and 31, respectively, in the same manner as described above. GCU100 is configured to send commands for controlling battery strings St1, St2 and St3 to SCU12, 22 and 32 and control converters 11, 21 and 31 by outputting three-phase AC power from the first power supply circuit 2.

[0085] Converter 11 converts the AC power (three-phase AC power) input from the power system PG through the power line PGL, distribution board C1, relay R1, and insulation filter T1 into DC power and outputs it to the battery string St1. SU1 can use the DC power supplied from converter 11 to charge the battery B in the battery string St1. At this time, GCU 100 controls SU1 so that the voltage of the battery string St1 is slightly lower than the AC voltage supplied from the power system PG. SU1 can charge any one of the multiple batteries B in the battery string St1 by controlling SW51 and SW52 of each battery circuit module M included in the battery string St1. For example, SU1 charges a designated battery B according to instructions from GCU 100. In SU2 and SU3, the batteries B included in the battery strings St2 and St3 are charged in the same way as described above. GCU100 is configured to send instructions for controlling battery strings St1, St2 and St3 to SCU12, 22 and 32 and control converters 11, 21 and 31 in a manner that allows the specified batteries B contained in battery strings St1, St2 and St3 to be charged.

[0086] like Figure 1 As shown, converters 11, 21, and 31 are connected in parallel with respect to the isolation filter T1. Specifically, the midpoint of each phase arm of converters 11, 21, and 31 (refer to...) Figure 8The first power supply circuit 2 is connected to the insulation filter T1 via wires. It uses parallel-connected battery strings St1, St2, and St3 and converters 11, 21, and 31 to output three-phase AC power (first AC power). In this embodiment, the first power supply circuit 2 includes three parallel-connected DC battery strings (battery strings St1, St2, and St3). Increasing the number of parallel-connected DC battery strings makes it easier to stabilize the AC power waveform output from the first power supply circuit 2. However, the number of DC battery strings included in the first power supply circuit 2 is not limited to three; it can be varied appropriately, and may include one or more than four. The first power supply circuit 2 can also be configured to output single-phase AC power.

[0087] Figure 9 This is a diagram showing the structure of the second power supply circuit 3. (Refer to...) Figure 9 Battery strings St4, St5, St6, St7, St8, and St9 correspond to the battery strings for the first U phase, the second U phase, the first V phase, the second V phase, the first W phase, and the second W phase, respectively.

[0088] The positive terminals of battery strings St4 and St5 are connected to wire PLU. The positive terminals of battery strings St6 and St7 are connected to wire PLV. The positive terminals of battery strings St8 and St9 are connected to wire PLw. Additionally, the negative terminals of each of battery strings St4 through St9 are connected to the neutral point N1. In the second power supply circuit 3, the parallel-connected battery strings St4 and St5, St6 and St7, and St8 and St9 are Y-connected.

[0089] SCU41-46 utilize control commands from GCU100 to... Figure 2 The SW51 and SW52 of each battery circuit module M shown are controlled by a switching frequency of tens of kHz to adjust the series voltage (output voltage) of each battery string St4 to St9 to become... Figure 9 The voltage waveform shown below is used for control. Figure 9 In the diagram, line L11 represents the series voltage of the battery strings (battery strings St4 and St5) for phase U. Line L12 represents the series voltage of the battery strings (battery strings St6 and St7) for phase V. Line L13 represents the series voltage of the battery strings (battery strings St8 and St9) for phase W. Lines L11, L12, and L13 are sine waves with a 120° phase shift, and their frequency corresponds to the frequency of the power system PG (e.g., 60Hz).

[0090] The series voltages of battery strings St4 to St9 are controlled as described above, and the line-to-line voltages of wires PLU, PLV, and PLW become... Figure 9The voltage waveform shown above. Figure 9 In the diagram, line L21 represents the voltage "Vuv" between wires Plu and Plv, line L22 represents the voltage "Vwu" between wires PLw and Plu, and line L23 represents the voltage "Vvw" between wires PLv and PLw. Each voltage is a sinusoidal alternating current waveform with its polarity (positive / negative) changing periodically.

[0091] As described above, the second power supply circuit 3 uses battery strings St4 to St9 to output three-phase AC power (second AC power). In the second power supply circuit 3, the battery strings for the U phase (battery strings St4 and St5), the battery strings for the V phase (battery strings St6 and St7), and the battery strings for the W phase (battery strings St8 and St9) are connected by a Y-connection, enabling the second power supply circuit 3 to output AC power (more specifically, three-phase AC power) without the use of an inverter. This reduces costs. In this embodiment of the second power supply circuit 3, multiple battery strings are connected in parallel as AC battery strings for each phase. The more parallel the number of AC battery strings, the easier it is to finely adjust the AC power waveform output from the second power supply circuit 3. However, the number of AC battery strings included in the second power supply circuit 3 is not limited to 6; it can be varied appropriately, and may also be 3 or even 1. Furthermore, the second power supply circuit 3 can also be configured to output single-phase AC power.

[0092] Refer again Figure 1 The SU1 to SU3 included in the first power supply circuit 2 and the SU4 to SU9 included in the second power supply circuit 3 are connected via the switching device C3. Figure 10 This is a diagram showing the detailed structure of the switching device C3.

[0093] and Figure 1 Refer to together Figure 10 One end of the switching device C3 is connected to the wires PL of the battery strings St1 to St3. Figure 2 At the other end of the switching device C3, wires PLU, PLv, and PLw are connected. Hereinafter, wire PL of battery string St1 will also be referred to as "wire PL1", wire PL of battery string St2 will also be referred to as "wire PL2", and wire PL of battery string St3 will also be referred to as "wire PL3". When the switching device C3 does not receive an instruction from GCU100, wires PL1 to PL3 are electrically insulated from wires PLU, PLv, and PLw. However, when the switching device C3 receives an instruction from GCU100, it will connect any one of wires PL1 to PL3 to any one of wires PLU, PLv, or PLw according to that instruction.

[0094] Specifically, the switching device C3 includes relay devices C31 and C32 and a wire SWL connecting the relay devices C31 and C32. The relay device C31 is configured to switch the connection / disconnection of each of the wires PL1 to PL3 with the wire SWL. In this embodiment, the relay device C31 has a relay for each wire. The relay device C31 can connect one or more selected wires from PL1 to PL3 to the wire SWL, or it can disconnect all of PL1 to PL3 from the wire SWL. The relay device C32 is configured to switch the connection / disconnection of each of the wires PLU, PLv, and PLw with the wire SWL. In this embodiment, the relay device C32 has a relay for each wire. The relay device C32 can connect one or more selected wires from PLU, PLv, and PLw to the wire SWL, or it can disconnect all of PLU, PLv, and PLw from the wire SWL.

[0095] In this embodiment, each of the relay devices C31 and C32 has a NO (Normally-Open) contact relay for each wire. Each NO contact relay in relay devices C31 and C32 is controlled by GCU100. However, this is not a limitation, and the structure of the switching device C3 can be appropriately modified. Each of the relay devices C31 and C32 may also include a relay that switches multiple contacts, such as a CO (Change-Over) contact relay.

[0096] Figure 11 This diagram illustrates an example of the operation of the switching device C3. (Refer to...) Figure 11When the GCU100 controls the switching device C3 by connecting wires PL1 and PLU, the GCU100 uses relay device C31 to connect wires PL1 and SWL, and relay device C32 to connect wires PLU and SWL. Thus, the positive terminals of battery string St1 and battery strings St4 and St5 are electrically connected, enabling power exchange between battery strings St1 and St4 and St5. In this way, in power system 1, the AC battery strings (battery strings St4 to St9) and DC battery strings (battery strings St1 to St3) are configured to exchange power. When charging battery B contained in the AC battery strings (e.g., battery strings St4 and St5) using the DC battery string (e.g., battery string St1), the GCU100 supplies power from the DC battery string to the AC battery string, making the voltage of the AC battery string lower than the voltage of the DC battery string. Conversely, when supplying power from the AC battery string to the DC battery string, the GCU100 makes the voltage of the DC battery string lower than the voltage of the AC battery string. In this embodiment, power exchange mainly occurs between DC battery strings and AC battery strings, but it is also possible to further exchange power between DC battery strings or between AC battery strings.

[0097] Refer again Figure 1 The AC power output from the first power supply circuit 2 is supplied to the power line PGL via an insulation filter T1, a relay R1, and a distribution board C1. The AC power output from the second power supply circuit 3 is supplied to the power line PGL via an insulation filter T2, a relay R2, and a distribution board C1. The power supply system 1 is configured such that, during system cooperative operation, three-phase AC power is supplied to the power system PG from at least one of the first power supply circuit 2 and the second power supply circuit 3 in a reverse flow manner.

[0098] Each of the insulation filters T1 and T2 includes, for example, an LCL filter and a three-phase transformer. Each of the insulation filters T1 and T2 utilizes an LCL filter to reduce noise components in the three-phase AC power, and uses a three-phase transformer to convert the three-phase AC power to a specified voltage (e.g., 200V) and provides insulation between the input and output sides. In this embodiment, each of the converters 11, 21, and 31 is a reused product used for other purposes (xEV drive), and its performance may not be high. Therefore, noise is easily included in the output of these converters. The insulation filter T1, disposed between the first power supply circuit 2 and the wire PGL, is configured to remove such noise. The insulation filter T1 may also have higher noise removal performance than the insulation filter T2.

[0099] Relays R1 and R2 are each, for example, electromagnetic mechanical relays. GCU100 is configured to switch the connection (parallel connection) / disconnection (splitting) of the first power supply circuit 2 with the power system PG by controlling the on / off state of relay R1. Furthermore, GCU100 is configured to switch the connection (parallel connection) / disconnection (splitting) of the second power supply circuit 3 with the power system PG by controlling the on / off state of relay R2.

[0100] Distribution board C1 supplies power from the power system PG to the first power circuit 2 and the second power circuit 3 respectively. Additionally, distribution board C1 supplies power from at least one of the first power circuit 2 and the second power circuit 3 to the power system PG and / or building 300 (distribution board C2). The AC power output from the first power circuit 2 and the second power circuit 3, together with the AC power output from the power system PG, is supplied to the wiring PGL, and then to the wiring within building 300 via distribution board C2.

[0101] The power supply system 1 is configured to perform a first output that outputs AC power (first AC power) only from the first power circuit 2 of the first power circuit 2 and the second power circuit 3, a second output that outputs AC power (second AC power) only from the second power circuit 3, and a dual output that outputs AC power (first AC power and second AC power) from both. In the dual output, the first power circuit 2 and the second power circuit 3 simultaneously output AC power. Furthermore, the power supply system 1 is configured to perform a first input that inputs AC power only to the first power circuit 2 of the first power circuit 2 and the second power circuit 3, a second input that inputs AC power only to the second power circuit 3, and a dual input that inputs AC power to both. In the dual input, AC power is simultaneously input to the first power circuit 2 and the second power circuit 3. In this embodiment, the GCU 100 selects and executes any one of the following: the first output, the second output, the dual output, the first input, the second input, and the dual input.

[0102] GCU100 is configured to switch between a first output, a second output, and both outputs. GCU100 is also configured to switch between a first input, a second input, and both inputs. During the execution of the first output or first input, GCU100 turns relay R1 on and relay R2 off. During the execution of the second output or second input, GCU100 turns relay R1 off and relay R2 on. During the execution of both outputs or both inputs, GCU100 turns both relays R1 and R2 on. When neither the first power supply circuit 2 nor the second power supply circuit 3 is performing any input or output, GCU100 turns both relays R1 and R2 off.

[0103] Figure 1 The server 200, as shown, requests power adjustments from the power system PG to the GCU 100 as needed. The server 200 can also implement DR (Demand Response). For example, the server 200 may prompt the user terminal with the conditions for the power adjustment. The conditions for the power adjustment indicate the content of the power adjustment (energy management) requested from the server 200. In this embodiment, the conditions for the power adjustment include the type of power adjustment (in this embodiment, either AC power output or AC power input), the adjustment period (indicating the start and end times of the adjustment), and the required power quantity (kW). Furthermore, if the user of power system 1 responds to the server 200 with an agreement in response to the notification of the aforementioned conditions, a power adjustment contract is established between the power company (TSO) and the user. The user's response of agreement signifies that the user agrees to the power adjustment with the prompted conditions. In this embodiment, the conditions for the power adjustment are prompted to the user from the TSO, but this is not a limitation. The conditions for the power adjustment may also be prompted to the user from an integrator or the electricity market.

[0104] If the user responds with the above agreement, the prompted power adjustment conditions are saved to the storage device of GCU100. The user terminal can be a vehicle-mounted terminal, a mobile terminal carried by the user, or GCU100. Examples of mobile terminals include laptops, smartphones, wearable devices, electronic keys, and service tools. The user terminal can be configured to respond to server 200 with a signal indicating either agreement or rejection based on the user's action upon receiving the notification of the above condition prompt from server 200. In the case where the user terminal is a vehicle-mounted terminal or a mobile terminal, the power adjustment conditions agreed to by the user are sent from the user terminal to GCU100. Alternatively, GCU100 can be configured to automatically determine agreement or rejection based on the prompted power adjustment conditions and the state of power system 1 upon receiving the notification of the above condition prompt from server 200, and reply to server 200 with its determination result. If an agreement is responded to, GCU100 saves the agreed power adjustment conditions to the storage device.

[0105] Server 200 remotely controls the input and output power of at least one of the first power supply circuit 2 and the second power supply circuit 3 by sending instructions to GCU 100 at the timed arrival of the aforementioned adjustment start time, thereby performing power adjustment of the power system PG. If GCU 100 receives an instruction from server 200 in a state where remote control is enabled (hereinafter also referred to as "remote on state"), it controls at least one of the first power supply circuit 2 and the second power supply circuit 3 according to the instruction from server 200. The aforementioned instruction may also be a signal representing the input and output current value (output current value or input current value). On the other hand, if GCU 100 receives an instruction from server 200 in a state where remote control is disabled (hereinafter also referred to as "remote off state"), it does not process the instruction from server 200.

[0106] The state of the GCU100 related to remote control (remote on / remote off state) can also be switched according to user settings. Alternatively, the user terminal can switch the GCU100 to the remote on state via wired or wireless communication when sending a response of agreement to the server 200. Furthermore, in the method of the GCU100 responding to the aforementioned agreement, it can also switch from the remote off state to the remote on state when the GCU100 has responded with agreement.

[0107] Figure 12 This is a flowchart illustrating an example of the processing performed by the GCU100 in the remote-on state. The processing shown in this flowchart begins when the GCU100 switches from the remote-off state to the remote-on state if there is a consented but unimplemented power adjustment (i.e., a power adjustment that has been consented to but not yet implemented). Hereinafter, each step in the flowchart will be abbreviated as "S".

[0108] and Figure 1 and Figure 2 Refer to together Figure 12 In S11, GCU100 adjusts the SOC of the DC battery strings (battery strings St1 to St3) included in the first power supply circuit 2 and the AC battery strings (battery strings St4 to St9) included in the second power supply circuit 3 based on agreed power adjustment conditions. Figure 13 This is a flowchart showing the details of S11 (SOC adjustment).

[0109] and Figure 1 and Figure 2 Refer to together Figure 13In S101, GCU100 sets the first SOC value, first time, second SOC value, and second time to be used in S111, S112, S121, and S122, respectively. Hereinafter, the first SOC value, second SOC value, first time, and second time will be referred to as "Vs1", "Vs2", "Vt1", and "Vt2", respectively.

[0110] In this embodiment, GCU100 uses the required adjustment period to determine Vs1, Vs2, Vt1, and Vt2. GCU100 may set Vs1 higher the longer the required AC power output period (adjustment period). GCU100 may set Vs2 lower the longer the required AC power input period (adjustment period). Furthermore, Vt1 and Vt2 can each be the same as the adjustment period, or they can be a period with a margin added to the adjustment period. In this embodiment, only one of Vs1, Vt1, Vs2, and Vt2 is used depending on the type of power adjustment required and the magnitude of the required power.

[0111] In the next step, S102, GCU100 determines whether the requested power adjustment is AC power output or AC power input. If the requested power adjustment is AC power output, the process proceeds to S103. If the requested power adjustment is AC power input, the process proceeds to S104.

[0112] In S103, GCU100 determines whether the requested output power (kW) is greater than a first reference value (hereinafter referred to as "Th1"). Th1 represents the range of output power that the second output can handle better than the outputs of both (the upper limit of the output power suitable for the second output). For example, a value that the user has pre-determined experimentally may be set as Th1.

[0113] When the required output power is below Th1 (not in S103), GCU100, in S111, performs power exchange between the AC battery string and the DC battery string in a manner that makes the SOC of the AC battery string (e.g., the average SOC of battery strings St4 to St9) above Vs1. Specifically, GCU100 controls the first power supply circuit 2, the second power supply circuit 3, and the switching device C3 in a manner that supplies power from the DC battery string (battery strings St1 to St3) to the AC battery string (battery strings St4 to St9). Figure 10 At this time, GCU100, together with switching device C3, controls SW51 and SW52 (including those in each battery string) by supplying power from DC batteries with high SOC to AC batteries with low SOC. Figure 2Therefore, the SOC of the AC battery string becomes above Vs1, and the SOC of each battery can be made equal.

[0114] If the required output power is greater than Th1 (in S103), GCU100 adjusts the SOC of each of the DC battery string (battery strings St1 to St3) and the AC battery string (battery strings St4 to St9) in S112 to ensure that the time for both outputs is greater than or equal to Vt1. Specifically, GCU100 considers the power consumption per unit time (predicted value) during both outputs and determines the target SOC of each of the AC and DC battery strings to ensure that the time for both outputs is greater than or equal to Vt1. Furthermore, GCU100 controls the switching device C3 ( Figure 10 The power exchange occurs between the AC battery string and the DC battery string. The GCU100 controls the first power circuit 2, the second power circuit 3, and the switching device C3 while bringing the SOC of each of the AC and DC battery strings close to the target SOC. Thus, the SOC of the DC battery string (e.g., the average SOC of battery strings St1 to St3) and the SOC of the AC battery string (e.g., the average SOC of battery strings St4 to St9) are adjusted in a balanced manner.

[0115] It should be noted that, in Figure 13 In the process shown, if the required output power is consistent with Th1, the process enters S111, but it can also be changed to enter S112 instead of S111.

[0116] In S104, GCU100 determines whether the requested input power (kW) is greater than a second reference value (hereinafter referred to as "Th2"). Th2 represents the range of input power that the second input provides a better response compared to both inputs (the upper limit of the input power suitable for the second input). For example, a value that the user has pre-determined experimentally could be set as Th2.

[0117] When the required input power is Th2 or less (not in S104), GCU100, in S121, performs power exchange between the AC battery string and the DC battery string in a manner that makes the SOC of the AC battery string (e.g., the average SOC of battery strings St4 to St9) less than Vs2. Specifically, GCU100 controls the first power supply circuit 2, the second power supply circuit 3, and the switching device C3 in a manner that supplies power from the AC battery string (battery strings St4 to St9) to the DC battery string (battery strings St1 to St3). Figure 10At this time, GCU100, together with switching device C3, controls SW51 and SW52 (see reference) in each battery string by supplying power from AC batteries with high SOC to DC batteries with low SOC, thereby controlling SW51 and SW52 (see reference). Figure 2 Therefore, the SOC of the AC battery string becomes below Vs2, and the SOC of each battery can be made equal.

[0118] If the required input power is greater than Th2 (in S104), GCU100 adjusts the SOC of each of the DC battery string (battery strings St1 to St3) and the AC battery string (battery strings St4 to St9) in S122 to ensure that the time for both inputs is greater than Vt2. Specifically, GCU100 considers the power consumption per unit time (predicted value) during both inputs and determines the target SOC of each of the AC and DC battery strings to ensure that the time for both inputs is greater than Vt2. Furthermore, GCU100 controls the switching device C3 ( Figure 10 The power exchange occurs between the AC battery string and the DC battery string. The GCU100 controls the first power circuit 2, the second power circuit 3, and the switching device C3 while bringing the SOC of each of the AC and DC battery strings close to the target SOC. Thus, the SOC of the DC battery string (e.g., the average SOC of battery strings St1 to St3) and the SOC of the AC battery string (e.g., the average SOC of battery strings St4 to St9) are adjusted in a balanced manner.

[0119] It should be noted that, in Figure 13 In the process shown, if the required input power is the same as Th2, the process proceeds to S121, but it can also be changed to proceed to S122 instead of S121.

[0120] After performing SOC adjustment in any of S111, S112, S121, and S122 above, Figure 13 The series of processes shown has ended, and processing has begun. Figure 12 S12.

[0121] Again with Figure 1 and Figure 2 Refer to together Figure 12In S12, GCU100 determines whether it has received an instruction from server 200. If GCU100 has not received the instruction (no in S12), the process proceeds to S14. In S14, GCU100 determines whether the remote control termination condition has been met. If the remote control termination condition has not been met (no in S14), the process returns to S12. For example, if GCU100 is in a remote shutdown state, the remote control termination condition is met. Additionally, the remote control termination condition is also met when a termination notification is received from server 200. However, this is not a limitation; the remote control termination condition can be arbitrarily set.

[0122] When GCU100 receives the above instruction (yes in S12), GCU100 performs input / output control according to the above instruction in S13.

[0123] For example, if the requested power adjustment is AC power output and the requested output power is less than Th1, GCU100 executes the second output according to the above instructions. Thus, the required AC power (i.e., the AC power according to the above instructions) is output from the second power supply circuit 3 (AC battery string) to the power system PG. As mentioned earlier, before the execution of the second output, an SOC adjustment is performed to make the SOC of the AC battery string greater than Vs1 (see [reference]). Figure 13 (S111). After the SOC of the AC battery string becomes above Vs1, the second output described above is executed.

[0124] When the requested power adjustment (energy management) is AC power output and the requested output power is greater than Th1, GCU100 executes the dual output according to the above instructions. Thus, the required AC power (i.e., AC power according to the above instructions) is output from the first power supply circuit 2 and the second power supply circuit 3 to the power system PG. As mentioned earlier, before the execution of the above dual output, the SOC adjustment of each AC battery string and DC battery string is performed (refer to...). Figure 13 (S112).

[0125] When the requested power adjustment is an AC power input and the requested input power is less than Th2, GCU100 executes the second input according to the above instructions. Thus, the required AC power (i.e., the AC power according to the above instructions) is input from the power system PG to the second power supply circuit 3 (AC battery string). As mentioned earlier, before the execution of the second input, an SOC adjustment is performed to make the SOC of the AC battery string below Vs2 (see [reference]). Figure 13 (S121). After the SOC of the AC battery string becomes below Vs2, the second input described above is executed.

[0126] When the requested power adjustment (energy management) is an AC power input and the requested input power is greater than Th2, GCU100 executes the dual input according to the above instructions. Thus, the required AC power (i.e., the AC power according to the above instructions) is input from the power system PG to the first power supply circuit 2 and the second power supply circuit 3. As mentioned earlier, before the execution of the above dual input, the SOC adjustment of each AC battery string and DC battery string is performed (refer to...). Figure 13 (S122).

[0127] After the input / output control according to the above instructions is executed in S13, the process proceeds to S14. During the period when the remote control termination condition is not met (no in S14), remote control based on instructions from server 200 (S12-S13) continues. Furthermore, if the remote control termination condition is met (yes in S14), then... Figure 12 The series of processes shown has ended. If the GCU100 is in the remote on state when the remote control termination condition is met, it can also switch from the remote on state to the remote off state after the GCU100 has switched off. Figure 12 The series of processes shown has ended.

[0128] The power adjustment of the power system PG by the power system 1 can also be performed by local control without relying on external commands. The GCU 100 can also obtain a charge / discharge plan for the power adjustment of the power system PG in advance from the server 200. For example, the charge / discharge plan can be included in the power adjustment conditions prompted by the server 200. The charge / discharge plan is information indicating the charge / discharge curve (i.e., the shift of the input and output power of the power system 1 relative to the power system PG) over a specified period. Furthermore, when the start time of the agreed power adjustment charge / discharge plan arrives, the GCU 100 can control the input and output power of at least one of the first power circuit 2 and the second power circuit 3 according to the charge / discharge plan.

[0129] Figure 14 This is a flowchart illustrating an example of the process performed when the GCU100 performs power adjustments according to a prescribed charge / discharge schedule. The process shown in the flowchart begins before the start time of the agreed-upon power adjustment charge / discharge schedule. For example, it can begin at a timing that traces back a predetermined time from the start time of the charge / discharge schedule (e.g., a time selected from a range of 15 minutes to 3 hours). Figure 14 The series of processes shown. In this embodiment, the SOC adjustment ( Figure 14 The time required for S21) is set to the time specified above.

[0130] and Figure 1 and Figure 2 Refer to together Figure 14 In S21, GCU100 performs SOC adjustment. In S21, with... Figure 12 Similarly, S11 executes... Figure 13 The process is shown below. Afterwards, in S22, GCU100 waits until the start time of the charge / discharge plan arrives. And, if the start time of the charge / discharge plan arrives, the process proceeds to S23.

[0131] In S23, GCU100 performs input / output control according to the aforementioned charge / discharge plan. At this time, GCU100 and the aforementioned... Figure 12 Similarly, in S13, the second output, dual output, second input, and dual input are switched according to the type of power adjustment requested and the magnitude of the requested power. After the input / output control according to the above-described charge / discharge plan is executed in S23, the process proceeds to S24. In S24, GCU100 determines whether the power adjustment termination condition has been met. The power adjustment termination condition is met when the end time of the charge / discharge plan arrives. The power adjustment termination condition may also be met when a termination notification is received from server 200. During the period when the power adjustment termination condition is not met (no in S24), the input / output control according to the above-described charge / discharge plan (S23) continues. Furthermore, if the power adjustment termination condition is met (yes in S24), then... Figure 14 The series of processes shown has ended.

[0132] As explained above, the power supply system 1 of this embodiment is configured to output AC power to the power supply object (electrical wire PGL). The power supply system 1 includes a first power supply circuit 2, a second power supply circuit 3, and a GCU 100 (control device). The first power supply circuit 2 includes a DC battery string (battery strings St1, St2, St3) for DC power and an converter (converter 11, 21, 31) for converting the DC power output from the DC battery string into AC power, configured to output the first AC power using the DC battery string and the converter. The second power supply circuit 3 includes an AC battery string (battery strings St4 to St9) for AC power, configured to output the second AC power using the AC battery string. The GCU 100 is configured to control the first power supply circuit 2 and the second power supply circuit 3. The AC battery string and the DC battery string are configured to exchange power (see reference). Figure 10 and Figure 11The AC battery string and the DC battery string each contain multiple battery circuit modules M connected in series. Each of the multiple battery circuit modules M contains a battery B, output terminals OT1 and OT2 for outputting the voltage of battery B, a first switch (SW51) connected to the output terminals OT1 and OT2 and in parallel with battery B, and a second switch (SW52) connected in series with battery B. The configuration is such that when the first switch is in the off state and the second switch is in the on state, the voltage of battery B is applied between the output terminals OT1 and OT2 (see reference). Figure 2 Furthermore, the GCU100 is configured to adjust the SOC (State of Charge) of the AC and DC battery strings respectively by exchanging power between the AC and DC battery strings before performing the required power adjustment (energy management). Figure 12 S11, Figure 13 and Figure 14 (S21).

[0133] Based on the above structure, before the execution of power regulation (energy management), both the AC battery string and the DC battery string are in a state that meets the required power regulation, making it easy to respond to the required power regulation. Furthermore, since SOC regulation is performed through the exchange of power between the AC and DC battery strings, SOC regulation can be performed without receiving power from an external power supply.

[0134] In the above embodiment, the power density of the batteries included in the DC battery string is higher than that of the batteries included in the AC battery string. Furthermore, the energy density of the batteries included in the AC battery string is higher than that of the batteries included in the DC battery string. In the power system 1 of this embodiment, by using high-capacity batteries at low-speed power supply or charging, long-term power supply or charging can be easily handled. Additionally, by using both high-output and high-capacity batteries at high-speed power supply or charging, long-term power supply or charging can be appropriately performed. By combining high-capacity and high-output batteries, fewer batteries are required compared to ensuring the same power supply or charging performance using only high-capacity batteries, thus reducing battery costs. In the power system 1 of the above embodiment, since the DC battery string is not used in low-speed input / output, the degradation of each DC battery (high-output battery) included in the DC battery string is suppressed.

[0135] In the aforementioned power adjustment (refer to) Figures 12-14 In this configuration, the second output, dual outputs, second input, and dual inputs are executed, but the first output and first input are not executed. The power supply system 1 can also be configured to execute either the first output or the first input according to a user's request. For example, the power supply system 1 can also supply power to the building 300 via the first output. However, it is not necessary for the power supply system 1 to be configured to execute both the first output and the first input.

[0136] Power generation equipment (e.g., naturally variable power sources such as solar or wind power generation equipment) may also be installed on building 300. Power system 1 may also be configured to store surplus electricity generated by the power generation equipment in a designated battery string. Alternatively, power system 1 may be configured to output power from the designated battery string to building 300 according to requests from building 300.

[0137] It should be considered that the embodiments disclosed herein are illustrative and not restrictive in all respects. The scope of the invention is defined not by the description of the above embodiments but by the claims, and is intended to include all modifications within the meaning and scope equivalent to the claims.

Claims

1. A power supply system, characterized in that, include: The first power supply circuit includes a DC battery string for DC power and a converter that converts the DC power output from the DC battery string into AC power, and outputs a first AC power using the DC battery string and the converter. The second power supply circuit has an AC battery string for AC power, and uses the AC battery string to output a second AC power. and The control device is configured to control the first power supply circuit and the second power supply circuit. The AC battery string and the DC battery string are configured to exchange power with each other. Each of the AC battery string and the DC battery string includes multiple battery circuit modules connected in series. Each of the plurality of battery circuit modules includes: Battery; The output terminal outputs the voltage of the battery. A first switch is connected to the output terminal and in parallel with the battery; and The second switch is connected in series with the battery. Each of the plurality of battery circuit modules is configured such that, when the first switch is in the off state and the second switch is in the on state, the voltage of the battery is applied to the output terminal. The control device is configured to adjust the SOC of the AC battery string and the DC battery string respectively by exchanging power between the AC battery string and the DC battery string before performing the required energy management.

2. The power supply system according to claim 1, characterized in that, The control device is configured to: supply power from the DC battery string to the AC battery string in such a way that the SOC of the AC battery string becomes greater than or equal to the first SOC value when the required energy management is AC power output and the required output power is less than a first reference value; and after the SOC of the AC battery string becomes greater than or equal to the first SOC value, output the required AC power from the second power supply circuit.

3. The power supply system according to claim 2, characterized in that, The control device is configured such that, when the required energy management is AC power output and the required output power is greater than the first reference value, after adjusting the respective SOC of the AC battery string and the DC battery string in a manner that enables the first power circuit and the second power circuit to simultaneously output AC power for a period of time greater than a first time, the required AC power is output from the first power circuit and the second power circuit.

4. The power supply system according to claim 3, characterized in that, The control device is configured to determine the first SOC value and the first time using the required period of the AC power output.

5. The power supply system according to any one of claims 1 to 4, characterized in that, The control device is configured to: supply power from the AC battery string to the DC battery string in such a way that the SOC of the AC battery string becomes below the second SOC value when the required energy management is AC power input and the required input power is less than a second reference value; and input the required AC power to the second power supply circuit after the SOC of the AC battery string becomes below the second SOC value.

6. The power supply system according to claim 5, characterized in that, The control device is configured such that, when the required energy management is AC power input and the required input power is greater than the second reference value, after adjusting the respective SOC of the AC battery string and the DC battery string in such a way that the time during which AC power can be simultaneously input to the first power circuit and the second power circuit becomes a second time or more, it inputs the required AC power to the first power circuit and the second power circuit.

7. The power supply system according to claim 6, characterized in that, The control device is configured to determine the second SOC value and the second time using the required period of the AC power input.

8. The power supply system according to any one of claims 1 to 7, characterized in that, The power density of the batteries in the DC battery string is higher than that of the batteries in the AC battery string. The energy density of the batteries in the AC battery string is higher than that of the batteries in the DC battery string.

9. The power supply system according to any one of claims 1 to 8, characterized in that, The first power supply circuit and the second power supply circuit are each electrically connected to an external power source that will supply power to the building and to the electrical wires connecting the building. The required energy management is the power regulation of the external power source.

10. The power supply system according to claim 9, characterized in that, It also includes an insulation filter disposed between the first power circuit and the wire. The converter is a reused product that has been used for other purposes.

11. The power supply system according to any one of claims 1 to 10, characterized in that, The first power supply circuit includes: a first driving circuit configured to drive the first switch and the second switch included in the DC battery string; and a first control circuit configured to send signals to the first driving circuit for driving the first switch and the second switch respectively according to instructions from the control device. The second power supply circuit includes: a second driving circuit configured to drive the first switch and the second switch included in the AC battery string; and a second control circuit configured to send signals to the second driving circuit for driving the first switch and the second switch respectively according to instructions from the control device.

12. The power supply system according to claim 11, characterized in that, The converter is a three-phase converter. The control device is configured to send commands for controlling the DC battery string to the first control circuit and control the converter by outputting three-phase AC power from the first power supply circuit. The AC battery string includes a battery string for the U phase, a battery string for the V phase, and a battery string for the W phase that are connected by a Y connection. The control device is configured to send commands for controlling the U-phase battery string, the V-phase battery string, and the W-phase battery string to the second control circuit in a manner that outputs three-phase AC power from the second power supply circuit.

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