Power supply system, program, and control method

Abstract

In a power supply system (10) equipped with a plurality of modules (20, 20A, 20B, 20C), each module comprises: a sub-positive electrode connection unit (101, 201, 301) that can be connected to the positive electrode terminal of an electricity storage unit (103, 203, 303); a sub-negative electrode connection unit (102, 202, 302) that can be connected to the negative electrode terminal of the electricity storage unit; a main positive electrode connection unit (104, 204, 304); and a main negative electrode connection unit (105, 205, 305). At least one of the modules is provided with a power converter (110, 210, 310) connected to the sub-positive electrode connection unit and the sub-negative electrode connection unit. The modules are connected in series such that the main negative electrode connection unit included in each module on the higher potential side and the main positive electrode connection unit included in each module on the lower potential side are connected to each other.

Description

Power Supply System, Program, Control Method Cross-Reference to Related Applications

[0001] This application is based on Japanese Application No. 2025-019944 filed on February 10, 2025, the contents of which are incorporated herein by reference.

[0002] The present disclosure relates to a power supply system, a program, and a control method.

[0003] Conventionally, as described in, for example, Patent Document 1, a power supply system including a power converter connected to a plurality of storage batteries and performing power exchange by controlling the power converter is known.

[0004] Japanese Patent No. 6470003

[0005] There is a power supply system including a plurality of modules connectable to a storage unit, with each module connected in series. In this system, a technique for adjusting the output voltage of the series connection of each module as desired is desired.

[0006] The present disclosure has been made to solve the above problems, and a main object thereof is to provide a power supply system, a program, and a control method capable of adjusting the output voltage of the series connection of each module.

[0007] In a power supply system including a plurality of modules, each of the modules includes a sub-positive connection part connectable to the positive terminal of the storage unit, a sub-negative connection part connectable to the negative terminal of the storage unit, a main positive connection part, and a main negative connection part. At least one of the modules includes a power converter connected to the sub-positive connection part and the sub-negative connection part. The modules are connected in series such that the main negative connection part included in the module on the high potential side is connected to the main positive connection part included in the module on the low potential side.

[0008] According to this disclosure, the output voltage of the modules can be adjusted by controlling the power converter. Therefore, the potential difference between the main negative electrode connection of the module with the lowest potential and the main positive electrode connection of the module with the highest potential can be adjusted.

[0009] The above-mentioned objectives and other objectives, features and advantages of this disclosure will become clearer from the following detailed description with reference to the attached drawings. The drawings are as follows: Figure 1 is a configuration diagram of the power supply system according to the first embodiment; Figure 2 is a configuration diagram of the power converter; Figure 3 is a flowchart of the control process of the power converter during discharge; Figure 4 is a diagram showing specific examples of the state of each battery, etc., during discharge; Figure 5 is a time chart showing the changes in SOC and current, etc., of each battery during discharge; Figure 6 is a flowchart of the control process of the power converter during charging; Figure 7 is a configuration diagram of the power supply system according to a modification of the first embodiment; Figure 8 is a configuration diagram of the power supply system according to a modification of the first embodiment; Figure 9 is a configuration diagram of the power supply system according to the second embodiment; Figure 10 is a configuration diagram of the power supply system according to the third embodiment; Figure 11 is a configuration diagram of the power supply system according to the fourth embodiment; and Figure 12 is a configuration diagram of the power converter according to the fifth embodiment. Figure 13 shows the operating modes of the power converter, Figure 14 shows the operating mode of the power converter when a positive voltage is output, Figure 15 shows the operating mode of the power converter when a negative voltage is output, Figure 16 shows the operating mode in the first quadrant, Figure 17 shows the operating mode in the second quadrant, Figure 18 shows the operating mode in the third quadrant, Figure 19 shows the operating mode in the fourth quadrant, Figure 20 is a configuration diagram of the power supply system according to the sixth embodiment, Figure 21 is a configuration diagram of the power supply system according to the seventh embodiment, Figure 22 is a flowchart of the control processing of the power converter, Figure 23 is a flowchart of the control processing of the power converter according to a modified example of the seventh embodiment, Figure 24 is a configuration diagram of the power converter according to another embodiment, and Figure 25 is a configuration diagram of the power converter according to another embodiment.

[0010] Multiple embodiments will be described with reference to the drawings. In multiple embodiments, functionally and / or structurally corresponding and / or related parts may be given the same reference numeral, or reference numerals that differ by hundreds or more digits. For corresponding and / or related parts, refer to the descriptions of other embodiments.

[0011] <First Embodiment> Hereinafter, a first embodiment of the power supply system according to the present disclosure will be described with reference to the drawings. The power supply system of this embodiment is, for example, a stationary system or a system mounted on a mobile body. The mobile body is, for example, a vehicle (e.g., an electric vehicle or a hybrid vehicle), an aircraft, or a ship.

[0012] Figure 1 shows a configuration diagram of the power supply system 10. The power supply system 10 comprises a unit 20 which includes multiple modules. In this embodiment, the unit 20 includes, as an example, three modules 100, 200, and 300.

[0013] The first, second, and third modules 100, 200, and 300 each include sub-positive terminals 101, 201, and 301 that can be connected to the positive terminals of the first, second, and third storage batteries (corresponding to the "storage units") 103, 203, and 303, and sub-negative terminals 102, 202, and 302 that can be connected to the negative terminals of the storage batteries 103, 203, and 303. Each storage battery 103, 203, and 303 is a rechargeable secondary battery, such as a lithium-ion battery or a nickel-metal hydride battery. In this embodiment, the rated voltage (for example, 400V) of each storage battery 103, 203, and 303 is the same.

[0014] The power supply system 10 comprises a main high-potential path 21H, a main low-potential path 21L, a smoothing capacitor 22, and electrical equipment 23. The smoothing capacitor 22 connects the main high-potential path 21H and the main low-potential path 21L. The smoothing capacitor 22 is connected in parallel to the electrical equipment 23.

[0015] The first, second, and third modules 100, 200, and 300 are configured to connect each module 100, 200, and 300 in series, and each module includes a main positive electrode connection section 104, 204, and 304, and a main negative electrode connection section 105, 205, and 305.

[0016] The main positive electrode connection 104 of the first module 100, which is the module with the highest potential, is connected to the main high-potential path 21H. The main negative electrode connection 305 of the third module 300, which is the module with the lowest potential, is connected to the main low-potential path 21L. As a result, the unit 20 is connected in parallel to the electrical equipment 23.

[0017] For example, if the power supply system 10 is a stationary system, the electrical equipment 23 is an ADC converter that converts AC power supplied from the grid power supply into DC power and supplies it to the unit 20. The ADC converter can also convert the DC power supplied from the unit 20 into AC power and supply it to the grid power supply.

[0018] Furthermore, for example, in the case of a system in which the power supply system 10 is mounted on a mobile body (e.g., an in-vehicle system), the electrical equipment 23 includes an inverter and a rotating electric machine having armature windings connected to the inverter. The inverter controls the current flowing through the armature windings of each phase. The rotating electric machine is an in-vehicle main machine, and the rotor of the rotating electric machine is capable of transmitting power to the drive wheels of the vehicle. The rotating electric machine is, for example, a permanent magnet synchronous machine. The electrical equipment 23 may also include, for example, a DC-DC converter, an external charger, or a heater.

[0019] Each module 100, 200, and 300 is equipped with a power converter 110, 210, and 310, respectively. Hereinafter, the power converters 110, 210, and 310 provided in the first, second, and third modules 100, 200, and 300 may be referred to as the first, second, and third power converters 110, 210, and 310.

[0020] The connection relationship between the battery and the power converter in each module 100, 200, and 300 will be explained in detail. The configurations of each module 100, 200, and 300 are basically the same. Therefore, the following explanation will focus on the first module 100.

[0021] In the first module 100, the first power converter 110 includes a first high-potential terminal 111H, a first low-potential terminal 111L, a second high-potential terminal 112H, and a second low-potential terminal 112L. The first high-potential terminal 111H is connected to a sub-positive terminal connection 101, and the first low-potential terminal 111L is connected to a sub-negative terminal connection 102. The second high-potential terminal 112H is connected to a main positive terminal connection 104, and the second low-potential terminal 112L is connected to a sub-positive terminal connection 101.

[0022] Figure 2 shows an example of the first power converter 110. The first power converter 110 is a center-tapped, isolated DC-DC converter. The first power converter 110 comprises a primary circuit 120 and a secondary circuit 130. Specifically, the primary circuit 120 of the first power converter 110 is connected in parallel to the first battery 103. The secondary circuit 130 of the first power converter 110 is connected in series to the first battery 103.

[0023] The primary side circuit 120 includes first and second upper arm switches S1H and S2H, and first and second lower arm switches S1L and S2L. In this embodiment, the first and second upper arm switches S1H and S2H and the first and second lower arm switches S1L and S2L are semiconductor switching elements, more specifically N-channel MOSFETs. Each switch S1H, S2H, S1L, and S2L has a body diode D1H, D2H, D1L, and D2L. Note that each switch S1H, S2H, S1L, and S2L may be, for example, an IGBT. In this case, a freewheeling diode is connected in antiparallel to each switch S1H, S2H, S1L, and S2L.

[0024] The first high-potential terminal 111H is connected to the drain, which is the high-potential terminal of the first upper arm switch S1H, and to the drain, which is the high-potential terminal of the second upper arm switch S2H. The drain of the first lower arm switch S1L is connected to the source, which is the low-potential terminal of the first upper arm switch S1H, and the drain of the second lower arm switch S2L is connected to the source of the second upper arm switch S2H. The first low-potential terminal 111L is connected to the sources of the first and second lower arm switches S1L and S2L.

[0025] The first power converter 110 includes an isolation transformer 140 that connects the primary circuit 120 and the secondary circuit 130. The isolation transformer 140 includes a primary coil 141 and a secondary coil 142 having a center tap 143. The first end of the primary coil 141 is connected to the connection point between the first upper arm switch S1H and the first lower arm switch S1L, and the second end of the primary coil 141 is connected to the connection point between the second upper arm switch S2H and the second lower arm switch S2L. The first end of the secondary coil 142 is connected to the source of the first switch SA, and the second end of the secondary coil 142 is connected to the source of the second switch SB. The center tap 143 of the secondary coil 142 is connected to the second low-potential terminal 112L.

[0026] The primary circuit 120 includes a first capacitor 121. The secondary circuit 130 includes a second capacitor 131. The first capacitor 121 is connected to a first high-potential terminal 111H and a first low-potential terminal 111L. The second capacitor 131 is connected to a second high-potential terminal 112H and a second low-potential terminal 112L.

[0027] The secondary circuit 130 includes a first switch SA and a second switch SB. The first switch SA and the second switch SB are semiconductor switching elements, specifically N-channel MOSFETs. Each switch SA and SB has body diodes DA and DB.

[0028] The first end of the reactor 132 is connected to the second high-potential terminal 112H. The second end of the reactor 132 is connected to the drain of the first switch SA and the drain of the second switch SB. The source of the first switch SA is connected to the first end of the secondary coil 142. The source of the second switch SB is connected to the second end of the secondary coil 142. In this embodiment, the secondary circuit 130 is configured to be able to execute only the positive voltage mode out of the positive voltage mode and negative voltage mode.

[0029] As shown in Figure 1, the second and third power converters 210 and 310 of the second and third modules 200 and 300 are center-tapped isolated DC-DC converters, similar to the first power converter 110, and are equipped with first high-potential terminals 211H, 311H and first low-potential terminals 211L, 311L.

[0030] The first module 100 includes a first drive circuit 160. The first drive circuit 160 turns on and off the first and second upper arm switches S1H and S2H, the first and second lower arm switches S1L and S2L, and the first and second switches SA and SB of the first power converter 110. The first drive circuit 160 charges and discharges the gates of each switch S1H, S2H, S1L, S2L, SA, and SB, and is controlled by a control device 170 provided in the power supply system 10. The second and third modules 200 and 300 also include second and third drive circuits 260 and 360, similar to the first module 100.

[0031] The power supply system 10 includes a main voltage sensor 30 and a main current sensor 31. The main voltage sensor 30 detects the system voltage, which is the potential difference between the main high-potential path 21H and the main low-potential path 21L. The main current sensor 31 detects the current flowing through the electrical equipment 23. In the example shown in Figure 1, the main current sensor 31 detects the current flowing through the portion of the main low-potential path 21L that is closer to the electrical equipment 23 than the connection point with the smoothing capacitor 22. The detected values ​​of each sensor 30 and 31 are input to the control device 170. The main current sensor 31 may also detect the current flowing through the portion of the main high-potential path 21H that is closer to the electrical equipment 23 than the connection point with the smoothing capacitor 22.

[0032] The first, second, and third modules 100, 200, and 300 are equipped with first, second, and third individual current sensors 161, 261, and 361, respectively. The first, second, and third individual current sensors 161, 261, and 361 are provided in correspondence with the first, second, and third storage batteries 103, 203, and 303, and detect the current flowing through the storage batteries 103, 203, and 303. The detected values ​​of each individual current sensor 161, 261, and 361 are input to the control device 170.

[0033] The first, second, and third modules 100, 200, and 300 are equipped with first, second, and third battery monitoring devices 162, 262, and 362, respectively, for monitoring the battery status. The first, second, and third battery monitoring devices 162, 262, and 362 are provided in correspondence with the first, second, and third storage batteries 103, 203, and 303, and acquire information on the battery status of the first, second, and third storage batteries 103, 203, and 303. The battery status information includes, for example, the terminal voltages of the first, second, and third storage batteries 103, 203, and 303, the temperatures of the first, second, and third storage batteries 103, 203, and 303, the state of charge (SOC) of the first, second, and third storage batteries 103, 203, and 303, and the state of heat (SOH) of the first, second, and third storage batteries 103, 203, and 303. The detected values ​​and acquired information from each battery monitoring device 162, 262, and 362 are input to the control device 170. In this embodiment, the first, second, and third battery monitoring devices 162, 262, and 362 correspond to "battery voltage sensors".

[0034] As shown in Figure 2, each power converter 110, 210, 310 is equipped with a first voltage sensor 151 and a second voltage sensor 154 (corresponding to a "secondary voltage sensor"), and a first current sensor 152 and a second current sensor 153. The first voltage sensor 151 detects the primary voltage, which is the potential difference between the first high-potential terminal 111H and the first low-potential terminal 111L. The second voltage sensor 154 detects the secondary voltage, which is the potential difference between the second high-potential terminal 112H and the second low-potential terminal 112L. The first current sensor 152 detects the primary current flowing through the primary circuit 120. The second current sensor 153 detects the secondary current flowing through the secondary circuit 130 (for example, the reactor 132). The detection values ​​from the sensors 151, 154, 152, and 153 of each power converter 110, 210, and 310 are input to the control device 170.

[0035] As shown in Figure 1, the control device 170 is an electronic control unit (ECU) that performs various controls on the power supply system 10, and comprises a processor 171 as hardware, a storage unit 172, and a communication bus 173 that connects the processor 171 and the storage unit 172.

[0036] The memory unit 172 includes memory and storage as hardware. The memory is a storage device for storing data used in processing by the control device 170. The memory provides the processor 171 with a temporary workspace for use when the processor 171 performs processing. The memory includes, for example, ROM or RAM. The storage is a storage device that stores various programs and data for the processor 171 to read and execute, and is a non-transitory tangible storage medium. The storage includes, for example, an HDD or flash memory. The storage stores program information and the like for processing described later.

[0037] For example, program information stored on a non-transitional physical recording medium is installed in the storage unit 172. The recording medium is, for example, a USB memory stick, a CD-ROM, or a DVD. Also, for example, program information transmitted via a communication network, such as OTA (Over The Air), is installed in the storage unit 172.

[0038] The control device 170 controls the switching of the primary circuit 120 and secondary circuit 130 of each power converter 110, 210, and 310 based on the input detected values. As a result, in each power converter 110, 210, and 310, the secondary voltages Vor1, Vor2, and Vor3 detected by the second voltage sensor 154 are controlled to target voltages Vo1*, Vo2*, and Vo3*. Consequently, in the first, second, and third modules 100, 200, and 300, the voltages VM1, VM2, and VM3 of the first, second, and third modules, which are the potential differences between the main positive electrode connection parts 104, 204, and 304 and the main negative electrode connection parts 105, 205, and 305, can be adjusted.

[0039] The main negative electrode connection 105 of the first module 100, which is on the relatively higher potential side, is connected to the main positive electrode connection 204 of the second module 200, which is on the relatively lower potential side. Similarly, the main negative electrode connection 205 of the second module 200, which is on the relatively higher potential side, is connected to the main positive electrode connection 304 of the third module 300, which is on the relatively lower potential side. As a result, modules 100, 200, and 300 are connected in series.

[0040] According to this embodiment, the module voltages VM1, VM2, and VM3 can be adjusted by switching control of each power converter 110, 210, and 310. Therefore, the unit voltage, which is the potential difference between the main negative electrode connection 305 of the third module 300 (the lowest potential side) and the main positive electrode connection 104 of the first module 100 (the highest potential side), can be adjusted.

[0041] In particular, in this embodiment, since each module 100, 200, and 300 is equipped with a power converter 110, 210, and 310, the range of adjustment for the unit voltage can be increased.

[0042] When the control device 170 of this embodiment charges and discharges each of the storage batteries 103, 203, and 303, it executes a process for reducing the variation in the SOC of each of the storage batteries 103, 203, and 303. This process will be described below.

[0043] First, the process when DC power is supplied from the unit 20 to the electrical device 23 will be described using FIG. 3. This process is repeatedly executed at a predetermined cycle.

[0044] In step S10, the detection information of each of the sensors 161, 261, 361, 151, 154, 152, and 153 and the acquired information of each of the battery monitoring devices 162, 262, and 362 are acquired.

[0045] In step S11, based on the information acquired in step S10, the total battery voltage VU, which is the total value of the terminal voltages of each of the storage batteries 103, 203, and 303, is calculated.

[0046] In step S12, the total adjustment voltage Vppctl is calculated by subtracting the calculated total battery voltage VU from the target system voltage Vbus*. The total adjustment voltage Vppctl is the total value of the target voltages Vo1*, Vo2*, and Vo3* of the secondary-side voltages in each of the power converters 110, 210, and 310.

[0047] In step S13, based on the calculated total adjustment voltage Vppctl and the SOC1, SOC2, and SOC3 of each of the storage batteries 103, 203, and 303 acquired in step S10, the target voltages Vo1*, Vo2*, and Vo3* are calculated. Specifically, the target voltages Vo1*, Vo2*, and Vo3* are calculated such that the discharge current increases as the stored power (specifically, SOC) in each of the storage batteries 103, 203, and 303 increases.

[0048] In step S14, switching control of each of the power converters 110, 210, and 310 is performed to control the secondary-side voltages Vor1, Vor2, and Vor3 to the calculated target voltages Vo1*, Vo2*, and Vo3*. Thereby, when each of the storage batteries 103, 203, and 303 discharges, the SOC of each of the storage batteries 103, 203, and 303 can be equalized.

[0049] Furthermore, the control device 170 may acquire the temperature sensor readings for the first, second, and third power converters 110, 210, and 310, and use the acquired temperature readings to calculate the target voltages Vo1*, Vo2*, and Vo3* in step S13. More specifically, the control device 170 may perform a process to limit (specifically, for example, reduce) the target voltage of the power converter among the first, second, and third power converters 110, 210, and 310 whose temperature exceeds a temperature threshold.

[0050] Using Figures 4 and 5, we will explain a specific example of the process described in Figure 3. In the example shown in Figure 4, the terminal voltages of each battery 103, 203, and 303 vary. Specifically, the terminal voltage Vb1 of the first battery 103 is 400V, the terminal voltage Vb2 of the second battery 203 is 390V, and the terminal voltage Vb3 of the third battery 303 is 380V.

[0051] Since the target system voltage Vbus* is 1200V, the total adjustment voltage Vppctl is 30V. In the example shown in Figure 4, the SOC1 of the first battery 103 is the largest, and the SOC3 of the third battery 303 is the smallest. Therefore, the target voltage Vo1* of the first power converter 110 is set to the highest value (20V) so that the discharge current Ib1 of the first battery 103 is the largest, and the target voltage Vo3* of the third power converter 310 is set to the lowest value so that the discharge current Ib3 of the third battery 303 is the smallest. In the example shown in Figure 4, the target voltage Vo3* of the third power converter 310 is set to 0V, so the switching control of the third power converter 310 is stopped. In Figure 4, Ib2 is the discharge current of the second battery 203.

[0052] As a result, as shown in Figure 5, the variation in SOC1, SOC2, and SOC3 of each battery 103, 203, and 303 is reduced over time. Figure 5 shows that, due to the reduction in variation, the degree of timing difference in when SOC1, SOC2, and SOC3 of each battery 103, 203, and 303 reach the lower limit of SOC, SLlim, is reduced.

[0053] Next, using Figure 6, we will explain the process when DC power is supplied from the electrical equipment 23 to the unit 20. This process is executed repeatedly at a predetermined cycle.

[0054] The processing in steps S20 to S22 is the same as the processing in steps S10 to S12 in Figure 5.

[0055] In step S23, target voltages Vo1*, Vo2*, and Vo3* are calculated based on the calculated total adjustment voltage Vppctl and the SOC1, SOC2, and SOC3 of each battery 103, 203, and 303 obtained in step S20. Specifically, the target voltages Vo1*, Vo2*, and Vo3* are calculated so that the charging current decreases as the amount of stored energy (specifically SOC) increases in each battery 103, 203, and 303.

[0056] In step S24, switching control of each power converter 110, 210, and 310 is performed to control the secondary voltages Vor1, Vor2, and Vor3 to the calculated target voltages Vo1*, Vo2*, and Vo3*. This makes it possible to equalize the state of charge (SOC) of each battery 103, 203, and 303 when each battery 103, 203, and 303 is charged.

[0057] <Modification of the First Embodiment> The rated voltages of each battery 103, 203, and 303 may be different. For example, the batteries housed in the unit 20 may be reused. Reused batteries may have different rated voltages and degradation states. Even in this case, according to the process shown in Figures 3 and 6, the SOC1, SOC2, and SOC3 of each battery 103, 203, and 303 can be properly adjusted along with the unit voltage.

[0058] As shown in Figure 7, the battery connected to the module may be a parallel connection of multiple batteries. Figure 7 shows an example in which the first battery 103 is configured as a parallel connection of three batteries, and the second battery 203 is configured as a parallel connection of two batteries. For example, if the rated capacity of the battery connected to the first module 100 (for example, a reused battery) is small, the rated capacity of the first battery 103 can be brought closer to the rated capacity of the third battery 303 by connecting multiple batteries with small rated capacities in parallel. In this case, batteries with similar degrees of degradation (e.g., State of Health) may be connected in parallel.

[0059] As shown in Figure 8, the individual current sensors for each module 100, 200, and 300 may be shared. Figure 8 shows an example in which only the first individual current sensor 161 is provided. This reduces the number of current sensors. In Figure 8, PT1 to PT7, shown by dot hatching, are examples of current paths in which current sensors can be set. Figure 8 shows an example in which the first individual current sensor 161 is provided in PT2.

[0060] Furthermore, the detection values ​​of the first individual current sensor 161 are used in the switching control of each power converter 110, 210, and 310. This suppresses the influence of detection errors of the current sensors on the switching control. As a result, the voltage control accuracy of each power converter 110, 210, and 310 can be improved.

[0061] <Second Embodiment> The second embodiment will now be described, focusing on the differences from the first embodiment, with reference to the drawings. In this embodiment, as shown in Figure 9, power converters are provided in only some of the modules among the multiple modules. In the example shown in Figure 9, the power converter 110 is provided only in the first module 100. The control device 170 can perform voltage control in the same way as the processes shown in Figures 3 and 6.

[0062] Furthermore, since the second and third batteries 203 and 303 connected to the second and third modules 200 and 300, which do not have power converters, cannot have their input and output power adjusted by a power converter, it is desirable that they be batteries with similar rated capacity and degradation levels.

[0063] Furthermore, it is desirable that the first battery 103 connected to the first module 100 equipped with a power converter 110 be a battery with a larger rated capacity or a lower degree of degradation (in other words, a higher state of health) than the second and third batteries 203 and 303.

[0064] <Third Embodiment> The third embodiment will now be described, focusing on the differences from the first embodiment, with reference to the drawings. In this embodiment, as shown in Figure 10, the first and second modules 100 and 200 are multi-modules equipped with multiple power converters. In order to increase the adjustable power between each battery, the secondary side circuits 130 of each power converter are connected in series in the multi-module.

[0065] In the example shown in Figure 10, the first module 100 includes three power converters, namely the first A, first B, and first C power converters 110A, 110B, and 110C, as a plurality of individual converters. In this embodiment, each power converter 110A, 110B, and 110C has the same configuration as the first power converter 110 in the first embodiment. Of the power converters 110A, 110B, and 110C, the downstream power converter is the first A power converter 110A, and the upstream power converter is the first C power converter 110C.

[0066] The main negative electrode connection section 105 is connected to the first low-potential side terminal 111L of each power converter 110A, 110B, and 110C. The sub positive electrode connection section 101 is connected to the first high-potential side terminal 111H of each power converter 110A, 110B, and 110C. The sub positive electrode connection section 101 is also connected to the second low-potential side terminal 112L of the downstream first A power converter 110A.

[0067] The second high-potential terminal 112H of the downstream first A power converter 110A is connected to the second low-potential terminal 112L of the intermediate first B power converter 110B. The second high-potential terminal 112H of the first B power converter 110B is connected to the second low-potential terminal 112L of the upstream first C power converter 110C.

[0068] The more power converters among the three power converters 110A, 110B, and 110C connected in series that perform the processing shown in Figure 3 or Figure 6, the greater the adjustment range of the module voltage.

[0069] Even if the first switch SA or the second switch SB in any of the secondary circuits 130 of each power converter 110A, 110B, or 110C experiences a short-circuit failure, the module voltage adjustment function can be maintained.

[0070] The second module 200 includes two power converters, the second A and second B power converters 210A and 210B. The connection relationship of the second A and second B power converters 210A and 210B is the same as that of the first module 100, so the explanation is omitted. Also, in Figure 10, the drive circuits and other components of the first A, first B, and first C power converters 110A, 110B, and 110C, and the second A and second B power converters 210A and 210B are not shown.

[0071] <Fourth Embodiment> The fourth embodiment will now be described, focusing on the differences from the first embodiment, with reference to the drawings. In this embodiment, as shown in Figure 11, the power supply system 10 is equipped with first, second, and third individual voltage sensors 163, 263, and 363. The first, second, and third individual voltage sensors 163, 263, and 363 detect the first, second, and third module voltages. The detected values ​​from the first, second, and third individual voltage sensors 163, 263, and 363 are input to the control device 170.

[0072] Next, we will explain the module abnormality detection process executed by the control device 170. The following explanation will use the first module 100 as an example.

[0073] The control device 170 determines whether or not an abnormality has occurred in the first module 100 based on the secondary voltage Vor1 detected by the second voltage sensor 154, the terminal voltage Vb1 of the first storage battery 103 detected by the first battery monitoring device 162, and the first module voltage VM1 detected by the first individual voltage sensor 163. Specifically, for example, if the control device 170 determines that the difference between "VM1" and "Vb1 + Vor1" exceeds a threshold, it may determine that an abnormality has occurred in the first module 100 (for example, the first power converter 110, the second voltage sensor 154, the first battery monitoring device 162, or the first individual voltage sensor 163). This determination method takes into account that if no abnormality occurs in the first module 100, the relationship "VM1 = Vb1 + Vor1" holds true.

[0074] <Fifth Embodiment> The fifth embodiment will now be described, focusing on the differences from the first embodiment, with reference to the drawings. In this embodiment, the configuration of the secondary circuit 130 has been changed, as shown in Figure 12. This configuration is for selecting and executing either a positive voltage mode in which the voltage of the second high-potential terminal 112H is increased relative to the second low-potential terminal 112L, or a negative voltage mode in which the voltage of the second high-potential terminal 112H is decreased relative to the second low-potential terminal 112L.

[0075] The secondary circuit 130 includes first to fourth switches SW1 to SW4. In this embodiment, the first to fourth switches SW1 to SW4 are semiconductor switching elements, more specifically N-channel MOSFETs. Each of the switches SW1 to SW4 also has body diodes D1 to D4.

[0076] The drain of the second switch SW2 is connected to the second end of reactor 132. The source of the first switch SW1 is connected to the source of the second switch SW2. The drain of the fourth switch SW4 is connected to the second end of reactor 132. The source of the third switch SW3 is connected to the source of the fourth switch SW4. The first end of the secondary coil 142 is connected to the drain of the first switch SW1. The drain of the third switch SW3 is connected to the second end of the secondary coil 142.

[0077] The control device 170 performs one of the first to fourth quadrant operations in the switching control of each power converter 110, 210, and 310. As shown in Figure 13, the first quadrant operation is the operation of discharging the battery while setting the secondary voltage Vor to a positive voltage. The second quadrant operation is the operation of discharging the battery while setting the secondary voltage Vor to a negative voltage. The third quadrant operation is the operation of charging the battery while setting the secondary voltage Vor to a negative voltage. The fourth quadrant operation is the operation of charging the battery while setting the secondary voltage Vor to a positive voltage. The first and fourth quadrant operations are positive voltage modes, and the second and third quadrant operations are negative voltage modes. The positive voltage mode is the mode when the target voltage of the secondary voltage is set to a positive value. The negative voltage mode is the mode when the target voltage of the secondary voltage is set to a negative value. Note that in the circuit shown in Figure 2 above, only the first and fourth quadrant operations are possible.

[0078] In positive voltage mode, the control device 170 keeps the first switch SW1 and the third switch SW3 ON, as shown in Figure 14. On the other hand, in negative voltage mode, the control device 170 keeps the second switch SW2 and the fourth switch SW4 ON, as shown in Figure 15.

[0079] If the control device 170 determines that the target voltage is a positive value, it performs either a first quadrant operation (see Figure 16) which transmits power from the primary circuit 120 to the secondary circuit 130, or a fourth quadrant operation (see Figure 19) which transmits power from the secondary circuit 130 to the primary circuit 120.

[0080] On the other hand, if the control device 170 determines that the target voltage is a negative value, it performs either a second quadrant operation (see Figure 17) in which power is transmitted from the secondary circuit 130 to the primary circuit 120, or a third quadrant operation (see Figure 18) in which power is transmitted from the primary circuit 120 to the secondary circuit 130.

[0081] Figure 16 shows the current path when the first quadrant operation is performed in the power converter. The following explanation will use the first power converter 110 as an example. When the control device 170 performs the first quadrant operation, it keeps the first switch SW1 and the third switch SW3 ON, and keeps the second switch SW2 and the fourth switch SW4 OFF, and performs switching control of the primary circuit 120 and the secondary circuit 130 so as to transmit power P from the primary circuit 120 to the secondary circuit 130. In this case, current flows to the secondary circuit 130 so that the first battery 103 is discharged. Specifically, the battery current Ia is output from the positive terminal of the first battery 103 and flows to the electrical equipment 23 side via the secondary circuit 130. The converter current Ib flows from the first battery 103 to the primary circuit 120.

[0082] In the first quadrant operation, power P is transmitted from the primary circuit 120 to the secondary circuit 130 with the charging direction of the first battery 103 blocked in the secondary circuit 130. In this case, the current flowing in the charging direction is blocked in the secondary circuit 130. As a result, the secondary voltage becomes a positive voltage while the first battery 103 is discharged.

[0083] Figure 17 shows the current path when the second quadrant operation is performed. When the control device 170 performs the second quadrant operation, it keeps the second switch SW2 and the fourth switch SW4 ON, and keeps the first switch SW1 and the third switch SW3 OFF, and performs switching control of the primary circuit 120 and the secondary circuit 130 so as to transmit power P from the secondary circuit 130 to the primary circuit 120. In this case, current flows to the secondary circuit 130 so that the first battery 103 is discharged. Specifically, the battery current Ia is output from the positive terminal of the first battery 103 and input to the secondary circuit 130. The converter current Ib flows from the primary circuit 120 to the secondary circuit 130. The battery current Ia and converter current Ib input to the secondary circuit 130 flow to the electrical equipment 23.

[0084] In the second quadrant operation, power P is transmitted from the secondary circuit 130 to the primary circuit 120 with the discharge direction of the first battery 103 blocked in the secondary circuit 130. In this case, the current flowing in the discharge direction of the first battery 103 is controlled in the secondary circuit 130, and power P is transmitted to the primary circuit 120. As a result, the first battery 103 is discharged while the secondary voltage becomes a negative voltage. In the second quadrant operation in negative voltage mode, the discharge current of the first battery 103 is smaller than in the first quadrant operation in positive voltage mode.

[0085] Figure 18 shows the current path when third quadrant operation is performed. When the control device 170 performs third quadrant operation, it keeps the second switch SW2 and the fourth switch SW4 ON, and keeps the first switch SW1 and the third switch SW3 OFF, and performs switching control of the primary circuit 120 and the secondary circuit 130 so as to transmit power P from the primary circuit 120 to the secondary circuit 130. In this case, current flows to the secondary circuit 130 so that the first storage battery 103 is charged. Specifically, the battery current Ia and the converter current Ib are input to the secondary circuit 130 from the electrical equipment 23. The battery current Ia input to the secondary circuit 130 flows to the positive terminal of the first storage battery 103. The converter current Ib is input to the primary circuit 120.

[0086] In the third quadrant operation, power P is transmitted from the primary circuit 120 to the secondary circuit 130 with the discharge direction of the first battery 103 blocked in the secondary circuit 130. In this case, the current flowing in the discharge direction is blocked in the secondary circuit 130. As a result, the first battery 103 is charged while the secondary voltage becomes a negative voltage.

[0087] Figure 18 shows the current path when the fourth quadrant operation is performed. When the control device 170 performs the fourth quadrant operation, it keeps the first switch SW1 and the third switch SW3 ON, and keeps the second switch SW2 and the fourth switch SW4 OFF, and performs switching control of the primary circuit 120 and the secondary circuit 130 so as to transmit power P from the secondary circuit 130 to the primary circuit 120. In this case, current flows to the secondary circuit 130 so that the first storage battery 103 is charged. Specifically, the battery current Ia is output from the electrical equipment 23 and input to the secondary circuit 130. The power input to the secondary circuit 130 is transmitted to the primary circuit 120, and the converter current Ib is output from the primary circuit 120. The battery current Ia and the converter current Ib flow to the positive terminal of the first storage battery 103.

[0088] In the fourth quadrant operation, power P is transmitted from the secondary circuit 130 to the primary circuit 120 with the charging direction of the first battery 103 blocked in the secondary circuit 130. In this case, the current flowing in the charging direction of the first battery 103 is controlled in the secondary circuit 130, and power P is transmitted to the primary circuit 120. As a result, the first battery 103 is charged while the secondary voltage becomes a positive voltage. In the third quadrant operation in negative voltage mode, the charging current of the first battery 103 is smaller than in the fourth quadrant operation in positive voltage mode.

[0089] This embodiment, which can perform both positive and negative voltage modes, allows for a wider range of adjustment of the unit voltage.

[0090] In this embodiment, in the process shown in Figure 3, the control device 170 performs a first quadrant operation in positive voltage mode in the secondary circuit 130 of the power converter connected to the battery with the largest SOC among the power converters 110, 210, and 310, and performs a second quadrant operation in negative voltage mode in the secondary circuit 130 of the power converter connected to the battery with the smallest SOC. The control device 170 may perform either the first quadrant operation or the second quadrant operation, or leave it non-operating (through), in the secondary circuit 130 of the power converter connected to the battery with an intermediate SOC among the power converters 110, 210, and 310.

[0091] When the positive voltage mode is executed, the discharge current of the battery is greater than when the negative voltage mode is executed. Therefore, variations in SOC1, SOC2, and SOC3 of each battery 103, 203, and 303 can be reduced early on.

[0092] In this embodiment, in the process shown in Figure 6, the control device 170 performs a negative voltage mode third quadrant operation in the secondary circuit 130 of the power converter connected to the battery with the largest SOC among the power converters 110, 210, and 310, and performs a positive voltage mode fourth quadrant operation in the secondary circuit 130 of the power converter connected to the battery with the smallest SOC. The control device 170 may perform a first quadrant operation or a second quadrant operation, or leave it non-operating (through), in the secondary circuit 130 of the power converter connected to the battery with the intermediate SOC among the power converters 110, 210, and 310.

[0093] When the positive voltage mode is executed, the charging current of the battery is greater than when the negative voltage mode is executed. Therefore, variations in SOC1, SOC2, and SOC3 of each battery 103, 203, and 303 can be reduced early on.

[0094] Furthermore, this embodiment may also be applied to the configuration shown in Figure 9.

[0095] <Sixth Embodiment> The sixth embodiment will now be described, focusing on the differences from the first embodiment, with reference to the drawings. In this embodiment, as shown in Figure 20, the configuration of each module 100, 200, and 300 has been changed. The configuration of each module 100, 200, and 300 is basically the same. Therefore, the following description will focus on the first module 100.

[0096] The main positive electrode connection section 104 and the sub positive electrode connection section 101 are connected to the first high-potential terminal 111H. The sub negative electrode connection section 102 is connected to the first low-potential terminal 111L and the second high-potential terminal 112H. The main negative electrode connection section 105 is connected to the second low-potential terminal 112L.

[0097] As described above, the same effects as those of the first embodiment can be achieved. The configuration of this embodiment may also be applied to the second to fifth embodiments.

[0098] <Seventh Embodiment> The seventh embodiment will now be described, focusing on the differences from the above embodiments, with reference to the drawings. In this embodiment, as shown in Figure 21, the power supply system 10 comprises multiple units. Figure 21 shows an example in which the power supply system 10 comprises three units 20A, 20B, and 20C. The configuration of each unit 20A, 20B, and 20C is basically the same.

[0099] In the first, second, and third units 20A, 20B, and 20C, the main positive electrode connection portion 104 (corresponding to the "end positive electrode connection portion") of the first module 100, which is on the highest potential side, is connected to the main high-potential path 21H. In the first, second, and third units 20A, 20B, and 20C, the main negative electrode connection portion 305 (corresponding to the "end negative electrode connection portion") of the third module 300, which is on the lowest potential side, is connected to the main low-potential path 21L. As a result, the first, second, and third units 20A, 20B, and 20C are connected in parallel. Consequently, the battery capacity for the electrical equipment 23 can be increased.

[0100] Next, we will explain the control performed by the control device 170.

[0101] The control device 170 switches the first, second, and third power converters 110, 210, and 310 provided in the first, second, and third units 20A, 20B, and 20C so that the difference between the highest and lowest voltages of the first, second, and third units 20A, 20B, and 20C is less than or equal to a predetermined value ΔVth. This makes it possible to equalize the voltages of the first, second, and third units. As a result, it suppresses the occurrence of inrush current or circulating current flowing from a unit with a relatively high unit voltage to a unit with a relatively low unit voltage among the first, second, and third units 20A, 20B, and 20C. The predetermined value ΔVth is set to a value that allows it to determine that the voltages of the first, second, and third units have equalized. For example, if Vsta is the rated voltage of each battery 103, 203, and 303 (for example, the minimum value among each battery 103, 203, and 303), then the predetermined value ΔVth should be set to "0 ≤ ΔVth ≤ Vsta / 40", "Vsta / 100 ≤ ΔVth ≤ Vsta / 40", or "Vsta / 100 ≤ ΔVth ≤ Vsta / 50".

[0102] Using Figure 22, the process when DC power is supplied to the electrical equipment 23 from each unit 20A, 20B, and 20C will be explained. This process is executed repeatedly at a predetermined cycle.

[0103] In step S30, detection and acquisition information from each of the sensors 161, 261, 361, 162, 262, 362, 151, 154, 152, and 153 provided by each of the units 20A, 20B, and 20C is acquired.

[0104] In step S31, based on the information acquired in step S30, the first total battery voltage VU1, which is the sum of the terminal voltages of each battery 103, 203, and 303 housed in the first unit 20A, is calculated. Also, based on the information acquired in step S30, the second total battery voltage VU2, which is the sum of the terminal voltages of each battery 103, 203, and 303 housed in the second unit 20B, is calculated. Furthermore, based on the information acquired in step S30, the third total battery voltage VU3, which is the sum of the terminal voltages of each battery 103, 203, and 303 housed in the third unit 20C, is calculated.

[0105] In step S32, the maximum total battery voltage among the calculated total battery voltages VU1, VU2, and VU3 is calculated as the target system voltage Vbus*.

[0106] In step S33, the variable N is set to 1. The variable N is a parameter used to identify one of the first, second, and third units 20A, 20B, and 20C. For example, if N = 1, the first unit 20A is identified.

[0107] In step S34, the nth total adjustment voltage Vppctl(N) of the nth unit is calculated by subtracting the nth total battery voltage VU(N) calculated in step S31 from the target system voltage Vbus* calculated in step S32.

[0108] In step S35, based on the calculated Nth total adjustment voltage Vppctl(N) and the SOC1, SOC2, and SOC3 of each battery 103, 203, and 303 obtained in step S30, the target voltages Vo1*, Vo2*, and Vo3* in the Nth unit are calculated in the same manner as in step S13 of Figure 3.

[0109] Furthermore, in the unit with the highest total battery voltage among the total battery voltages VU1, VU2, and VU3, the total adjustment voltage Vppctl becomes 0, and therefore the switching control of each power converter 110, 210, and 310 is stopped.

[0110] In step S36, the variable N is incremented by 1.

[0111] In step S37, it is determined whether the calculation of the target voltages Vo1*, Vo2*, and Vo3* has been completed for all units. Specifically, it is determined whether the variable N has reached the number of units "3".

[0112] In step S38, switching control of each power converter 110, 210, and 310 is performed in each unit 20A, 20B, and 20C to control the secondary voltages Vor1, Vor2, and Vor3 to the calculated target voltages Vo1*, Vo2*, and Vo3*.

[0113] This makes it possible to equalize the SOC of each battery 103, 203, and 303 in each unit 20A, 20B, and 20C while suppressing the generation of inrush current or circulating current.

[0114] Furthermore, the control device 170 can perform the same processing as in Figure 22 not only when discharging each unit 20A, 20B, and 20C, but also when charging each unit 20A, 20B, and 20C. In this case, the control device 170 can calculate the target voltages Vo1*, Vo2*, and Vo3* in the Nth unit, similar to step S33 in Figure 6.

[0115] <Modification of the 7th Embodiment> The control device 170 may perform ripple temperature rise control processing in conjunction with the processing shown in Figure 22. This processing involves raising the temperature of each storage battery 103, 203, 303 by charging and discharging current between each unit 20A, 20B, 20C. For example, when charging and discharging between the first and second units 20A and 20B, the control device 170 can switch the power converters 110, 210, 310 of the first and second units 20A and 20B so as to alternately switch the relative magnitudes of the voltages of the first and second units.

[0116] - The unit may be equipped with a secondary circuit 130 capable of executing a negative voltage mode. In this case, the control device 170 may, in the process of step S32 in Figure 22, calculate the target system voltage Vbus* from among the calculated total battery voltages VU1, VU2, and VU3, excluding the maximum value.

[0117] - When the process shown in Figure 22 is applied to the configuration shown in Figure 10, the control device 170 may, as shown in Figure 23, determine the number of power converters to be switched controlled in step S39 after the calculation of the target voltages Vo1*, Vo2*, Vo3* is completed. For example, the control device 170 determines the number M of power converters to be switched controlled from the first A, first B, and first C power converters 110A, 110B, and 110C. The control device 170 can then set the target voltage of the power converters to be switched controlled to "Vo1* / M" (M = 1, 2, 3).

[0118] <Other Embodiments> The above embodiments may be modified and implemented as follows.

[0119] The secondary circuit of the power converter is not limited to the above configuration, but may also have one of the following configurations (A) to (D).

[0120] (A) In the secondary circuit 130 shown in Figure 15, the first switch SW1 and the second switch SW2 may be swapped, and the fourth switch SW4 and the third switch SW3 may be swapped. In this case, the drain of the first switch SW1 is connected to the drain of the second switch SW2, and the drain of the third switch SW3 is connected to the drain of the fourth switch SW4.

[0121] (B) The switch in the secondary circuit 130 shown in Figure 2.15 may be an N-channel IGBT instead of an N-channel MOSFET. In this case, a freewheeling diode is connected in antiparallel to the switch.

[0122] (C) As shown in Figure 24, the secondary circuit 130 comprises a first switch section R1 and a second switch section R2. The first end of the secondary coil 142 and the second low-potential terminal 112L are connected by the first switch section R1. The second end of the secondary coil 142 and the second low-potential terminal 112L are connected by the second switch section R2. The first and second switch sections R1 and R2 are reverse-blocking IGBTs (RB-IGBTs). The first switch section R1 comprises a first H switch RH1 and a first L switch RL1 connected in antiparallel to the first H switch RH1. The second switch section R2 comprises a second H switch RH2 and a second L switch RL2 connected in antiparallel to the second H switch RH2. The secondary circuit 130 shown in Figure 24 is configured to be selectable and executable in either a positive voltage mode or a negative voltage mode.

[0123] (D) The secondary circuit 130 is not limited to a center-tapped circuit, but may be, for example, a full-bridge circuit as shown in Figure 25. The secondary circuit 130 includes a first switch section U1, a second switch section U2, a third switch section U3, and a fourth switch section U4. The first switch section U1 includes a series connection of a first H switch UH1 and a first L switch UL1. The first H switch UH1 and the first L switch UL1 are semiconductor switching elements, specifically N-channel MOSFETs. The source of the first H switch UH1 and the source of the first L switch UL1 are connected. The second switch section U2 includes a series connection of a second H switch UH2 and a second L switch UL2, with their sources connected to each other. The third switch section U3 includes a series connection of a third H switch UH3 and a third L switch UL3, with their sources connected to each other. The fourth switch section U4 comprises a series connection of the fourth H switch UH4 and the fourth L switch UL4, with their sources connected to each other. Each switch UH1, UL1, UH2, UL2, UH3, UL3, UH4, UL4 has body diodes DH1, DL1, DH2, DL2, DH3, DL3, DH4, DL4.

[0124] The second end of reactor 132 is connected to the second low-potential terminal 112L via a series connection of the first switch section U1 and the second switch section U2. The second end of reactor 132 is also connected to the second low-potential terminal 112L via a series connection of the third switch section U3 and the fourth switch section U4. The first end of secondary coil 142 is connected to the connection point of the first switch section U1 and the second switch section U2. The second end of secondary coil 142 is connected to the connection point of the third switch section U3 and the fourth switch section U4.

[0125] The primary circuit of the power converter is not limited to the configuration described above.

[0126] The power converter is not limited to isolated DC-DC converters; it may also be a non-isolated DC-DC converter such as a resonant DC-DC converter or a buck converter.

[0127] The number of modules a unit has may be two, or four or more.

[0128] In the seventh embodiment, the number of units provided by the power supply system 10 may be two or four or more.

[0129] The energy storage unit in each module is not limited to a battery; for example, it may include a large-capacity electric double-layer capacitor, or both a battery and an electric double-layer capacitor. Furthermore, the energy storage unit may also be a fuel cell.

[0130] In this disclosure or claims, the term "processor" means one or more hardware processors configured to execute processing defined by computer program code (i.e., one or more instructions of a computer program) contained in a computer program by reading the computer program code each time. In other words, a "processor" is a hardware device that executes one or more programmed processes. Therefore, computer program code can also be said to be software that can define the processing of the processor according to its content. A "processor" can be a general-purpose or specific-purpose processor, and may be, but is not limited to, a CPU, microprocessor, GPU, and DFP (Data Flow Processor).

[0131] In this disclosure or claims, the term “memory” means one or more hardware memories that are non-transitional tangible recording media configured to record computer program code and / or data in a manner accessible from a processor. “Memory” can be implemented by memory technology such as SRAM, SDRAM, non-volatile / flash type memory, or other types of memory. The computer program code that constitutes the program is recorded in memory and executed by a processor, thereby enabling the processor to perform the various functions described above.

[0132] In this disclosure or claims, the term “circuit” refers to one or more logic circuits as hardware, configured to perform specific processing defined by a pre-designed circuit configuration. In other words (and, in contrast to “processor”), “circuit” in this disclosure or claims refers to a hardware device that performs specific processing based on a circuit configuration, rather than processing defined by software such as the computer program code described above. For example, “circuit” may include custom ICs such as ASICs (Application Specific Integrated Circuits) and FPGAs (Field Programmable Gate Arrays) designed with Hardware Description Language (HDL). That is, “circuit” in this disclosure or claims includes all hardware circuits except for the processors described above that perform processing by reading computer program code.

[0133] In this disclosure or claims, the expression "at least one of the circuit and processor" should be interpreted as disjunctive (logical OR) and not as "at least one circuit and at least one processor." Therefore, in this disclosure or claims, "at least one of the circuit and processor causes the system to perform functions" includes cases where the circuit alone causes the system to perform all functions. Also, "at least one of the circuit and processor causes the system to perform functions" includes cases where the processor alone causes the system to perform all functions. Furthermore, "at least one of the circuit and processor causes the system to perform functions" includes cases where the circuit causes the system to perform some functions and the processor causes the system to perform the remaining functions. In the last example, for example, if the system performs functions A through C, functions A and B may be implemented by the circuit, and the remaining function C may be implemented by the processor.

[0134] The following describes the characteristic configurations extracted from each of the embodiments described above. [Configuration 1] A power supply system (10) comprising a plurality of modules (20, 20A, 20B, 20C), wherein each module comprises: a sub-positive connection part (101, 201, 301) connectable to the positive terminal of a power storage unit (103, 203, 303); a sub-negative connection part (102, 202, 302) connectable to the negative terminal of the power storage unit; a main positive connection part (104, 204, 304); and a main negative connection part (105, 205, 305), wherein at least one of the modules comprises a power converter (110, 210, 310) connected to the sub-positive connection part and the sub-negative connection part, and the modules are connected in series such that the main negative connection part of the module on the high potential side is connected to the main positive connection part of the module on the low potential side. [Configuration 2] The power converter comprises: a primary circuit (120) including first high-potential terminals (111H, 211H, 311H) connected to the sub-positive terminal connection and first low-potential terminals (111L, 211L, 311L) connected to the sub-negative terminal connection; a secondary circuit (130) including second high-potential terminals (112H, 212H, 312H) connected to the main positive terminal connection and second low-potential terminals (112L, 212L, 312L) connected to the sub-positive terminal connection; and an isolation transformer (140) connecting the primary circuit and the secondary circuit, wherein the power converter is the power supply system according to Configuration 1. [Configuration 3] The power converter comprises: a primary circuit (120) including first high-potential terminals (111H, 211H, 311H) connected to the main positive terminal connection and first low-potential terminals (111L, 211L, 311L) connected to the sub-negative terminal connection; a secondary circuit (130) including second high-potential terminals (112H, 212H, 312H) connected to the sub-negative terminal connection and second low-potential terminals (112L, 212L, 312L) connected to the main negative terminal connection; and an isolation transformer (140) connecting the primary circuit and the secondary circuit, wherein the power converter is the power supply system according to Configuration 1.[Configuration 4] The power supply system according to Configuration 2 or 3, wherein each module is equipped with the power converter. [Configuration 5] The power supply system according to any one of Configurations 2 to 4, wherein at least two of the modules are equipped with the power converter and a control device (170), and the control device controls the power converter so that, when the modules are discharged, the discharge current of the energy storage unit with a relatively large amount of stored energy, which is connected to each module equipped with the power converter, is greater than the discharge current of the energy storage unit with a relatively small amount of stored energy. [Configuration 6] The power supply system according to any one of Configurations 2 to 5, wherein at least two of the modules are equipped with the power converter and a control device (170), and the control device controls the power converter so that, when the modules are charged, the charging current of the energy storage unit with a relatively large amount of stored energy, which is connected to each module equipped with the power converter, is less than the charging current of the energy storage unit with a relatively small amount of stored energy. [Configuration 7] The power supply system according to Configuration 5 or 6, wherein the secondary circuit is configured to be able to select and execute either a positive voltage mode in which the voltage at the second high potential terminal is higher than the voltage at the second low potential terminal, or a negative voltage mode in which the voltage at the second low potential terminal is higher than the voltage at the second high potential terminal, and the control device controls the power converter so that the secondary circuit of the module connected to the energy storage unit with a relatively large amount of stored energy is set to the positive voltage mode, and the secondary circuit of the module connected to the energy storage unit with a relatively small amount of stored energy is set to the negative voltage mode. [Configuration 8] The power supply system according to Configuration 2 or 3, wherein some of the modules are equipped with the power converter, and in the modules that are not equipped with the power converter, the sub-positive electrode connection is connected to the main positive electrode connection and the sub-negative electrode connection is connected to the main negative electrode connection.[Configuration 9] The power supply system according to Configuration 8, wherein at least two of the modules are equipped with the power converter and a control device (170), and the control device controls the power converter so that, when the modules are discharged, the discharge current of the energy storage unit with a relatively large amount of stored energy, which is connected to each of the modules equipped with the power converter, is greater than the discharge current of the energy storage unit with a relatively small amount of stored energy. [Configuration 10] The power supply system according to Configuration 8 or 9, wherein at least two of the modules are equipped with the power converter and a control device (170), and the control device controls the power converter so that, when the modules are charged, the charging current of the energy storage unit with a relatively large amount of stored energy, which is connected to each of the modules equipped with the power converter, is less than the charging current of the energy storage unit with a relatively small amount of stored energy. [Configuration 11] The power supply system according to Configuration 9 or 10, wherein the secondary circuit is configured to be able to select and execute either a positive voltage mode in which the voltage at the second high potential terminal is higher than the voltage at the second low potential terminal, or a negative voltage mode in which the voltage at the second low potential terminal is higher than the voltage at the second high potential terminal, and the control device controls the power converter such that the secondary circuit of the module connected to the energy storage unit with a relatively large amount of stored energy is set to the positive voltage mode, and the secondary circuit of the module connected to the energy storage unit with a relatively small amount of stored energy is set to the negative voltage mode. [Configuration 12] The secondary circuit is configured to be able to select and execute either a positive voltage mode in which the voltage at the second high potential terminal is higher than the voltage at the second low potential terminal, or a negative voltage mode in which the voltage at the second low potential terminal is higher than the voltage at the second high potential terminal, and the control device controls the power converter so that when each module is being charged, the secondary circuit of the module connected to the energy storage unit with a relatively large amount of stored energy is set to the negative voltage mode, and the secondary circuit of the module connected to the energy storage unit with a relatively small amount of stored energy is set to the positive voltage mode, the power supply system according to any one of Configurations 9 to 11.[Configuration 13] A power supply system according to any one of Configurations 2 to 12, wherein a multimodule, which is at least some of the modules, comprises a plurality of power converters, and in the multimodule, the secondary side circuits of each power converter are connected in series. [Configuration 14] A power supply system according to any one of Configurations 2 to 13, comprising: a secondary voltage sensor (154) that detects the potential difference between the second high-potential side terminal and the second low-potential side terminal; battery voltage sensors (162, 262, 362) that detect the potential difference between the positive terminal and the negative terminal of the energy storage unit; individual voltage sensors (163, 263, 363) that detect the potential difference between the main positive terminal connection and the main negative terminal connection; and a control device (170), wherein the control device determines whether or not an abnormality has occurred in the module based on the detected values ​​of the secondary voltage sensor, the battery voltage sensor and the individual voltage sensor. [Configuration 15] A power supply system according to any one of Configurations 2 to 14, comprising a plurality of units (20A, 20B, 20C) which are series connections of each of the modules, wherein the main positive electrode connection of the module with the highest potential among the modules is used as the end positive electrode connection, and the main negative electrode connection of the module with the lowest potential among the modules is used as the end negative electrode connection, wherein the end positive electrode connections of each unit are connected to each other, and the end negative electrode connections of each unit are connected to each other. [Configuration 16] A power supply system according to Configuration 15, comprising a control device (170), wherein the control device controls the power converter so that the unit voltage, which is the potential difference between the end positive electrode connection and the end negative electrode connection, is the same for each unit. [Configuration 17] The power supply system according to Configuration 16, wherein at least two of the modules are equipped with the power converter, and the control device controls the power converter such that, when each module is discharged, the discharge current of the energy storage unit connected to each module equipped with the power converter, the energy storage unit with a relatively large energy storage capacity, is greater than the discharge current of the energy storage unit with a relatively small energy storage capacity.[Configuration 18] The power supply system according to Configuration 16 or 17, wherein at least two of the modules are equipped with the power converter, and the control device controls the power converter such that, when each module is being charged, the charging current of the energy storage unit connected to each module equipped with the power converter, the energy storage unit with a relatively large energy storage capacity, is smaller than the charging current of the energy storage unit with a relatively small energy storage capacity.

[0135] This disclosure is described in accordance with the embodiments, but it is understood that this disclosure is not limited to such embodiments or structures. This disclosure also includes various modifications and variations within the equivalence. In addition, various combinations and forms, as well as other combinations and forms that include only one, more, or fewer of those elements, fall within the scope and concept of this disclosure.

Claims

1. A power supply system (10) comprising a plurality of modules (20, 20A, 20B, 20C), wherein each module comprises: a sub-positive connection portion (101, 201, 301) connectable to the positive terminal of a power storage unit (103, 203, 303); a sub-negative connection portion (102, 202, 302) connectable to the negative terminal of the power storage unit; a main positive connection portion (104, 204, 304); and a main negative connection portion (105, 205, 305), wherein at least one of the modules comprises a power converter (110, 210, 310) connected to the sub-positive connection portion and the sub-negative connection portion, and the modules are connected in series such that the main negative connection portion of the module on the high-potential side is connected to the main positive connection portion of the module on the low-potential side.

2. The power converter comprises: a primary circuit (120) including first high-potential terminals (111H, 211H, 311H) connected to the sub-positive terminal connection and first low-potential terminals (111L, 211L, 311L) connected to the sub-negative terminal connection; a secondary circuit (130) including second high-potential terminals (112H, 212H, 312H) connected to the main positive terminal connection and second low-potential terminals (112L, 212L, 312L) connected to the sub-positive terminal connection; and an isolation transformer (140) connecting the primary circuit and the secondary circuit, the power supply system according to claim 1.

3. The power converter comprises: a primary circuit (120) including first high-potential terminals (111H, 211H, 311H) connected to the main positive terminal connection and first low-potential terminals (111L, 211L, 311L) connected to the sub-negative terminal connection; a secondary circuit (130) including second high-potential terminals (112H, 212H, 312H) connected to the sub-negative terminal connection and second low-potential terminals (112L, 212L, 312L) connected to the main negative terminal connection; and an isolation transformer (140) connecting the primary circuit and the secondary circuit, the power supply system according to claim 1.

4. The power supply system according to claim 2 or 3, wherein each module comprises the power converter.

5. The power supply system according to claim 2 or 3, wherein at least two of the modules are equipped with the power converter and a control device (170), the control device controls the power converter such that, when each module is discharged, the discharge current of the energy storage unit connected to each module equipped with the power converter, the energy storage unit with a relatively large energy storage capacity, is greater than the discharge current of the energy storage unit with a relatively small energy storage capacity.

6. The power supply system according to claim 2 or 3, wherein at least two of the modules are equipped with the power converter and a control device (170), and the control device controls the power converter during charging of each module such that the charging current of the energy storage units connected to each module equipped with the power converter, the energy storage units with a relatively large amount of stored energy, is smaller than the charging current of the energy storage units with a relatively small amount of stored energy.

7. The power supply system according to claim 5, wherein the secondary circuit is configured to be able to select and execute either a positive voltage mode in which the voltage at the second high potential terminal is higher than the voltage at the second low potential terminal, or a negative voltage mode in which the voltage at the second low potential terminal is higher than the voltage at the second high potential terminal, and the control device controls the power converter such that the secondary circuit of the module connected to the energy storage unit with a relatively large amount of stored energy is set to the positive voltage mode, and the secondary circuit of the module connected to the energy storage unit with a relatively small amount of stored energy is set to the negative voltage mode.

8. The power supply system according to claim 2 or 3, wherein some of the modules are equipped with the power converter, and in the modules that are not equipped with the power converter, the sub-positive electrode connection is connected to the main positive electrode connection and the sub-negative electrode connection is connected to the main negative electrode connection.

9. The power supply system according to claim 8, wherein at least two of the modules are equipped with the power converter and a control device (170), the control device controls the power converter such that, when each module is discharged, the discharge current of the energy storage unit connected to each module equipped with the power converter, the energy storage unit with a relatively large energy storage capacity, is greater than the discharge current of the energy storage unit with a relatively small energy storage capacity.

10. The power supply system according to claim 8, wherein at least two of the modules are equipped with the power converter and a control device (170), the control device controls the power converter during charging of each module such that the charging current of the energy storage units connected to each module equipped with the power converter, the energy storage units with a relatively large amount of stored energy, is smaller than the charging current of the energy storage units with a relatively small amount of stored energy.

11. The power supply system according to claim 9, wherein the secondary circuit is configured to be able to select and execute either a positive voltage mode in which the voltage at the second high potential terminal is higher than the voltage at the second low potential terminal, or a negative voltage mode in which the voltage at the second low potential terminal is higher than the voltage at the second high potential terminal, and the control device controls the power converter such that, when each module is discharged, the secondary circuit of the module connected to the energy storage unit with a relatively large amount of stored energy is set to the positive voltage mode, and the secondary circuit of the module connected to the energy storage unit with a relatively small amount of stored energy is set to the negative voltage mode.

12. The power supply system according to claim 9, wherein the secondary circuit is configured to be able to select and execute either a positive voltage mode in which the voltage at the second high potential terminal is higher than the voltage at the second low potential terminal, or a negative voltage mode in which the voltage at the second low potential terminal is higher than the voltage at the second high potential terminal, and the control device controls the power converter such that, when charging each module, the secondary circuit of the module connected to the energy storage unit with a relatively large amount of stored energy is set to the negative voltage mode, and the secondary circuit of the module connected to the energy storage unit with a relatively small amount of stored energy is set to the positive voltage mode.

13. The power supply system according to claim 2 or 3, wherein a multimodule, which is at least some of the modules, comprises a plurality of power converters, and in the multimodule, the secondary side circuits of each power converter are connected in series.

14. A power supply system according to claim 2 or 3, comprising: a secondary voltage sensor (154) for detecting the potential difference between the second high-potential terminal and the second low-potential terminal; battery voltage sensors (162, 262, 362) for detecting the potential difference between the positive terminal and the negative terminal of the energy storage unit; individual voltage sensors (163, 263, 363) for detecting the potential difference between the main positive terminal connection and the main negative terminal connection; and a control device (170), wherein the control device determines whether or not an abnormality has occurred in the module based on the detected values ​​of the secondary voltage sensor, the battery voltage sensor and the individual voltage sensor.

15. The power supply system according to claim 2 or 3, comprising a plurality of units (20A, 20B, 20C) which are series connections of the respective modules, wherein the main positive electrode connection of the module with the highest potential among the modules is designated as the end positive electrode connection, and the main negative electrode connection of the module with the lowest potential among the modules is designated as the end negative electrode connection, wherein the end positive electrode connections of each unit are connected to each other, and the end negative electrode connections of each unit are connected to each other.

16. The power supply system according to claim 15, comprising a control device (170), wherein the control device controls the power converter so that the unit voltage, which is the potential difference between the positive terminal connection portion and the negative terminal connection portion, is the same for each unit.

17. The power supply system according to claim 16, wherein at least two of the modules are equipped with the power converter, and the control device controls the power converter such that, when each module is discharged, the discharge current of the energy storage unit connected to each module equipped with the power converter, the energy storage unit with a relatively large energy storage capacity, is greater than the discharge current of the energy storage unit with a relatively small energy storage capacity.

18. The power supply system according to claim 16, wherein at least two of the modules are equipped with the power converter, and the control device controls the power converter such that, when each module is being charged, the charging current of the energy storage unit connected to each module equipped with the power converter, the energy storage unit with a relatively large energy storage capacity, is smaller than the charging current of the energy storage unit with a relatively small energy storage capacity.

19. In a program applied to a power supply system (10) comprising multiple modules (20, 20A, 20B, 20C), each module comprises: sub-positive connection parts (101, 201, 301) connectable to the positive terminals of the energy storage units (103, 203, 303); sub-negative connection parts (102, 202, 302) connectable to the negative terminals of the energy storage units; main positive connection parts (104, 204, 304); and main negative connection parts (105, 205, 305). At least two of the modules comprises power converters (110, 210, 310) connected to the sub-positive and sub-negative connection parts. The power converters adjust the module voltage, which is the potential difference between the main positive and main negative connection parts, by controlling the power converters. The modules are connected in series such that the main negative electrode connection portion of the high-potential module and the main positive electrode connection portion of the low-potential module are connected, and a program causes at least one of the processor (171) and the circuit to execute a process to control the power converter during the discharge of each module such that, among the energy storage units connected to each module equipped with the power converter, the discharge current of the energy storage unit with a relatively large energy storage capacity is greater than the discharge current of the energy storage unit with a relatively small energy storage capacity.

20. In a program applied to a power supply system (10) comprising multiple modules (20, 20A, 20B, 20C), each module comprises: sub-positive connection parts (101, 201, 301) connectable to the positive terminals of the energy storage units (103, 203, 303); sub-negative connection parts (102, 202, 302) connectable to the negative terminals of the energy storage units; main positive connection parts (104, 204, 304); and main negative connection parts (105, 205, 305). At least two of the modules comprises power converters (110, 210, 310) connected to the sub-positive and sub-negative connection parts. The power converters adjust the module voltage, which is the potential difference between the main positive and main negative connection parts, by controlling the power converters. The modules are connected in series such that the main negative electrode connection portion of the high-potential module and the main positive electrode connection portion of the low-potential module are connected, and a program causes at least one of the processor (171) and the circuit to execute a process to control the power converter during charging of each module such that the charging current of the energy storage unit with a relatively large energy storage capacity is smaller than the charging current of the energy storage unit with a relatively small energy storage capacity, among the energy storage units connected to each module equipped with the power converter.

21. A control method applied to a power supply system (10) comprising a plurality of modules (20, 20A, 20B, 20C), wherein each module comprises: a sub-positive connection portion (101, 201, 301) connectable to the positive terminal of a power storage unit (103, 203, 303); a sub-negative connection portion (102, 202, 302) connectable to the negative terminal of the power storage unit; a main positive connection portion (104, 204, 304); and a main negative connection portion (105, 205, 305), wherein at least two of the modules comprises power converters (110, 210, 310) connected to the sub-positive and sub-negative connection portions, and the power converter adjusts the module voltage, which is the potential difference between the main positive and main negative connection portions, by controlling the power converter. A control method comprising: each of the modules being connected in series such that the main negative electrode connection portion of the high-potential module and the main positive electrode connection portion of the low-potential module are connected; and causing at least one of the processor (171) and the circuit to execute a process to control the power converter during the discharge of each module such that, among the energy storage units connected to each of the modules equipped with the power converter, the discharge current of the energy storage unit with a relatively large energy storage capacity is greater than the discharge current of the energy storage unit with a relatively small energy storage capacity.

22. A control method applied to a power supply system (10) comprising a plurality of modules (20, 20A, 20B, 20C), wherein each module comprises: a sub-positive connection portion (101, 201, 301) connectable to the positive terminal of a power storage unit (103, 203, 303); a sub-negative connection portion (102, 202, 302) connectable to the negative terminal of the power storage unit; a main positive connection portion (104, 204, 304); and a main negative connection portion (105, 205, 305), wherein at least two of the modules comprises power converters (110, 210, 310) connected to the sub-positive and sub-negative connection portions, and the power converter adjusts the module voltage, which is the potential difference between the main positive and main negative connection portions, by controlling the power converter. A control method comprising: each of the modules is connected in series such that the main negative electrode connection portion of the high-potential module and the main positive electrode connection portion of the low-potential module are connected; and at least one of the processor (171) and the circuit executes a process to control the power converter during charging of each module such that, among the energy storage units connected to each of the modules equipped with the power converter, the charging current of the energy storage unit with a relatively large energy storage capacity is smaller than the charging current of the energy storage unit with a relatively small energy storage capacity.

Images