Power supply system and control program

Abstract

To improve the accuracy of current control in a power supply system.SOLUTION: A power supply system (10) includes a storage battery (31, 61), a conversion circuit (40, 70) in which a primary side terminal pair (41, 42, 71, 72) is connected in parallel to the storage battery and a secondary side terminal pair (47, 48, 77, 78) is connected in series to the storage battery, and which converts power by driving a switching element, and a control unit (16b) that controls the charge / discharge current of the storage battery by driving the switching element on and off based on a switching command. The control unit can execute a plurality of control modes for calculating a switching command based on an output current command value for the conversion circuit, executes calculation of the switching command in the plurality of control modes in parallel, selects one switching command from a plurality of calculated switching commands, and drives the switching element based on the selected switching command.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a power supply system. [Background technology]

[0002] For example, there is a system in which the positive and negative electrodes of a storage battery are connected to a pair of input terminals of a conversion circuit, and the storage battery is connected in series to a pair of output terminals of the conversion circuit (see Patent Document 1). Patent Document 1 suggests that in order to discharge or charge the storage battery, control is switched based on whether it is discharging or charging, or on the state of the storage battery (SOC: State Of Charge). [Prior art documents] [Non-patent literature]

[0003] [Non-Patent Document 1] IEEE ECCE2019(P5783-P5790) Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the system described in Patent Document 1, when switching control, a delay in control response or a current overshoot may occur, which may reduce the current control accuracy. In particular, a system mounted on a vehicle to supply power to a load requires high current control accuracy.

[0005] The present invention has been made to solve the above-mentioned problems, and its main objective is to improve the accuracy of current control in a power supply system in which the primary terminal pair of a conversion circuit is connected in parallel to a storage battery and the secondary terminal pair is connected in series to the storage battery. [Means for solving the problem]

[0006] The first means for solving the above problem is a conversion circuit (40, 70) having a primary side terminal pair (41, 42, 71, 72) connected in parallel to the storage battery and a secondary side terminal pair (47, 48, 77, 78) connected in series to the storage battery, and converting power by driving switching elements (43-46, 54, 55, 143-146); and a control unit (16b) controlling a charge / discharge current of the storage battery by driving the switching elements on and off based on a switching command, The control unit is capable of executing a plurality of control modes for calculating the switching command based on an output current command value for the conversion circuit, executes the calculation of the switching command using the plurality of control modes in parallel, selects one of the calculated plurality of switching commands, and drives the switching element based on the selected switching command.

[0007] According to the above configuration, the conversion circuit has a primary terminal pair connected in parallel to the storage battery and a secondary terminal pair connected in series to the storage battery, and converts power by driving a switching element. Therefore, the sum of the output voltage Vb of the storage battery and the output voltage Vo of the conversion circuit becomes the output voltage Vm of the storage battery module including the storage battery and the conversion circuit. Therefore, compared with a storage battery module in which a storage battery is connected in parallel to the secondary terminal pair of the conversion circuit, the output voltage Vo required of the conversion circuit when the output voltage Vm is required of the storage battery module can be reduced. Therefore, the rated voltage of the conversion circuit can be reduced, and the rated capacity of the conversion circuit can be reduced, thereby making it possible to miniaturize the conversion circuit.

[0008] The control unit controls the charge / discharge current of the storage battery by driving the switching element on and off based on a switching command. The control unit can execute a plurality of control modes that calculate the switching command based on an output current command value for the conversion circuit. Therefore, when controlling the charge / discharge current of the storage battery, the control unit can switch between a plurality of control modes in response to a request to the power supply system.

[0009] Here, the control unit executes the calculation of the switching command according to the plurality of control modes in parallel. Therefore, regardless of which control mode is to be switched to, the switching command in the plurality of control modes can be calculated in advance. Then, the control unit selects one of the calculated plurality of switching commands and drives the switching element based on the selected switching command. Therefore, regardless of which control mode switching command is selected, the switching element can be quickly driven by the already calculated switching command. Therefore, it is possible to suppress the occurrence of a control response delay when switching the control mode, and to improve the control accuracy of the current.

[0010] In the second means, the control unit is capable of executing a plurality of the control modes when discharging or charging the storage battery, and selects the switching command with the earliest switching timing from the plurality of switching commands calculated when discharging or charging the storage battery.

[0011] According to the above configuration, the control unit can execute a plurality of the control modes when discharging or charging the storage battery. Therefore, when discharging or charging the storage battery, the control unit can switch between a plurality of control modes in response to a request to the power supply system. Then, the control unit selects the switching command having the earliest switching timing (e.g., rising timing of an on-off drive signal) from among the plurality of switching commands calculated for discharging or charging the storage battery. Therefore, when the switching command changes, the change in the switching command can be quickly reflected in the drive of the switching element. Therefore, the response delay of the control can be further reduced.

[0012] The third means includes a plurality of current sensors (19, 33, 52, 58, 63) that detect currents in different paths, and the plurality of control modes during discharging or charging include the control mode in which the switching command is calculated based on the detection values ​​of at least two current sensors among the plurality of current sensors. With this configuration, the plurality of current sensors can detect currents in different paths. Therefore, it is possible to execute control modes with different control methods based on the detection values ​​of at least two current sensors among the plurality of current sensors, and to improve the current control accuracy in each control mode.

[0013] In a fourth aspect, the multiple current sensors include at least two of a current sensor (52) that detects a primary current flowing through the primary terminal pair of the conversion circuit, a current sensor (58) that detects a secondary current flowing through the secondary terminal pair of the conversion circuit, and a current sensor (33, 63) that detects a current flowing through the storage battery. With this configuration, it is possible to execute a peak current mode based on a peak value of current and an input current, or execute an average current mode based on an average value of current and an output current.

[0014] In a fifth aspect, the plurality of control modes during discharging or charging include a peak current mode in which the switching command is calculated based on a peak value of a current flowing through the primary terminal pair of the conversion circuit, and an average current mode in which the switching command is calculated based on an average value of a current flowing through the secondary terminal pair of the conversion circuit. With this configuration, the peak current mode can improve the control response of the charge / discharge current of the storage battery, and the average current mode can improve the control accuracy of the charge / discharge current of the storage battery.

[0015] In a sixth aspect, at least one of the average current modes includes a continuous current mode in which a current flows continuously through the secondary terminal pair, and a discontinuous current mode including a period in which the current flows through the secondary terminal pair becomes 0, and the control unit has a correction term for the switching command that differs between the continuous current mode and the discontinuous current mode. With this configuration, it is possible to improve the accuracy of current control when the continuous current mode is executed and when the discontinuous current mode is executed.

[0016] In the seventh aspect, the control unit calculates the correction term based on the primary voltage between the primary terminal pair and the secondary voltage between the secondary terminal pair. With this configuration, the correction term can be properly calculated, and the current control accuracy can be improved when the continuous current mode is executed and when the discontinuous current mode is executed. The input voltage can be calculated by multiplying the output voltage by the turns ratio of the transformer.

[0017] In the eighth means, when only a predetermined control mode is executed at the current output current command value for the conversion circuit, the control unit does not execute the calculation of the switching command in the plurality of control modes in parallel, and prioritizes execution of the calculation of the switching command only at the predetermined control mode. With this configuration, when only a predetermined control mode is executed at the current output current command value for the conversion circuit, it is possible to omit the calculation of unnecessary switching commands. Therefore, it is possible to reduce the processing load of the control unit.

[0018] In a ninth means, the control unit selects a selectable switching command from the plurality of switching commands calculated based on the output current command value for the conversion circuit, and selects one of the selectable switching commands.

[0019] According to the above configuration, first, the selectable switching commands can be narrowed down from the calculated multiple switching commands based on the output current command value for the conversion circuit. Then, one switching command is selected from the selectable switching commands. Therefore, even if the calculated multiple switching commands are large in number, it is easy to select an appropriate switching command.

[0020] Specifically, in the tenth means, the control unit is capable of selecting, from the plurality of calculated switching commands, the switching command of the control mode that is executable when discharging the storage battery when the output current command value for the conversion circuit is greater than 0, and is capable of selecting, from the plurality of calculated switching commands, the switching command of the control mode that is executable when charging the storage battery when the output current command value for the conversion circuit is less than 0. With this configuration, it is possible to smoothly switch between the control mode during discharging and the control mode during charging, with the output current command value becoming 0 as the boundary.

[0021] An eleventh means includes a primary side current sensor (52) that detects a primary side current flowing through the primary side terminal pair of the conversion circuit, and a secondary side current sensor (58) that detects a secondary side current flowing through the secondary side terminal pair of the conversion circuit, the multiple control modes include a control mode that calculates the switching command based on the detection values ​​of the primary side current sensor and the secondary side current sensor, and the storage battery and the conversion circuit constitute a storage battery module (30, 60), and the storage battery module includes the primary side current sensor.

[0022] According to the above configuration, a switching command can be calculated based on a detection value of a primary side current sensor included in the storage battery module, so there is no need to provide a dedicated current sensor just for detecting the current flowing through the primary side terminal pair of the conversion circuit.

[0023] In a twelfth aspect, a secondary voltage sensor (59) is provided for detecting a voltage between the secondary terminal pair of the conversion circuit, and the control unit calculates the switching command based on the voltage detected by the secondary voltage sensor, or a bus voltage sensor (13) is provided for detecting a voltage of a power supply bus (11, 12) to which the storage battery and the conversion circuit are connected, and the control unit calculates the switching command based on the voltage detected by the bus voltage sensor. With this configuration, the switching command is calculated based on one of the secondary voltage sensor and the bus voltage sensor, so that the other can be omitted. Note that the voltage between the secondary terminal pair can be calculated by subtracting the voltage of the storage battery (i.e., the voltage between the primary terminal pair) from the voltage detected by the bus voltage sensor.

[0024] The thirteenth measure is: A control program applied to a power supply system (10, 210) including a storage battery (31, 61) and a conversion circuit (40, 70) that converts power by driving switching elements (43-46, 54, 55, 143-146), the control program comprising: A process of controlling a charge / discharge current of the storage battery by driving the switching element based on a switching command; A process of executing a plurality of control modes for calculating the switching command based on an output current command value for the conversion circuit; A process of calculating the switching commands in the plurality of control modes in parallel, selecting one of the plurality of switching commands thus calculated, and driving the switching element based on the selected switching command; The computer (16) executes the above.

[0025] According to the above configuration, by causing a computer to execute a control program applied to the power supply system, it is possible to achieve the same advantageous effects as the first means. [Brief description of the drawings]

[0026] [Figure 1] Circuit diagram of the power supply system. [Diagram 2] FIG. 4 is a circuit diagram showing an example of a conversion circuit. [Diagram 3] 5 is a flowchart showing a control mode switching procedure. [Figure 4] 4 is a timing chart showing current in continuous mode and discontinuous mode. [Diagram 5] FIG. 1 is a block diagram showing FF terms for continuous and discontinuous modes. [Figure 6] FIG. 4 is a block diagram showing a flow of outputting a drive signal based on switching timing. [Figure 7] 4 is a time chart showing the current command value and the primary side current in peak current mode during discharge. [Figure 8] 4 is a time chart showing the current command value and the secondary current in the average current mode during discharge. [Figure 9] 4 is a time chart showing an output current command value and an output current. [Figure 10] 4 is a time chart showing the current command value in the peak current mode during discharge and the primary side current in the average current mode during discharge. [Figure 11] FIG. 11 is a circuit diagram of a modified example of a power supply system. [Figure 12] FIG. 11 is a circuit diagram of another modified example of the power supply system. [Figure 13] FIG. 11 is a circuit diagram of another modified example of the power supply system. [Figure 14] FIG. 13 is a circuit diagram of a modified example of the conversion circuit. [Figure 15] FIG. 13 is a circuit diagram of another modified example of the conversion circuit. [Figure 16] FIG. 11 is a circuit diagram of a modified example of the storage battery module. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0027] Hereinafter, an embodiment of a power supply system that is mounted on a vehicle and supplies power to a load will be described with reference to the drawings.

[0028] 1, power supply system 10 includes buses 11 and 12 (power supply buses), a first storage battery module 30, a second storage battery module 60, a voltage sensor 13, a current sensor 19, an ECU (Electronic Control Unit) 16, etc. The positive side of the buses is referred to as bus 11, and the negative side of the buses is referred to as bus 12. Bus 12 is grounded.

[0029] A first storage battery module 30 (storage battery module), a second storage battery module 60 (storage battery module), a load 21, and a voltage sensor 13 are connected in parallel to the buses 11 and 12. The storage battery modules 30 and 60 input and output power to the buses 11 and 12. The load 21 inputs power from the buses 11 and 12, or inputs and outputs power to the buses 11 and 12. The voltage sensor 13 (bus voltage sensor) detects a bus voltage Vbus, which is a voltage between the buses 12 and 11. The current sensor 19 detects a current flowing through the bus 12 (load 21).

[0030] The load 21 is, for example, a combination of an inverter and a motor generator (MG) (motor unit with inverter), an electric heater, a DC-DC converter, or the like. The motor generator (MG) drives, for example, an electric vehicle with power supplied from the inverter, or performs regenerative power generation with a rotational force applied from the electric vehicle. The inverter converts power between the buses 11, 12 and the MG. The electric heater generates heat with, for example, a high voltage supplied from the buses 11, 12, and warms the interior of the vehicle or the battery. The DC-DC converter converts, for example, DC power supplied from the buses 11, 12 and supplies DC power, or converts DC power supplied from a solar panel or the like and supplies DC power to the buses 11, 12. The load 21 may be singular or plural.

[0031] The first storage battery module 30 includes a first storage battery 31, a first current sensor 33, a first drive circuit 35, a first conversion circuit 40, relays 40a, 40b, etc. The first storage battery 31 (storage battery) is a high-voltage secondary battery using, for example, a lithium-ion battery, a nickel-metal hydride battery, etc., and the type is arbitrary. The first current sensor 33 (current sensor) detects a current flowing through the first storage battery 31. A detection value by the first current sensor 33 is input to the ECU 16 and is used, for example, to calculate the state of charge (SOC) of the first storage battery 31. The first drive circuit 35 (drive circuit) drives a switching element (described later) included in the first conversion circuit 40 to turn on and off. The first drive circuit 35 is controlled by the ECU 16. The relays 40a, 40b disconnect and connect the storage battery module 30 to and from the buses 11, 12, respectively. The first storage battery 31 (storage battery) may be a secondary battery that is not a high voltage battery.

[0032] The first conversion circuit 40 (conversion circuit) includes a primary side positive terminal 41 and a negative terminal 42, which are a primary side terminal pair, and a secondary side positive terminal 47 and a negative terminal 48, which are a secondary side terminal pair. The negative electrode of the first storage battery 31 is connected to the bus 12. The primary side positive terminal 41 is connected to the positive electrode of the first storage battery 31, and the primary side negative terminal 42 is connected to the negative electrode of the first storage battery 31. In addition, the secondary side negative terminal 48 is connected to the positive electrode of the first storage battery 31. The secondary side positive terminal 47 is connected to the bus 11. That is, the positive electrode and the negative electrode of the first storage battery 31 are connected to the primary side terminal pair 41, 42 of the first conversion circuit 40, respectively (the first storage battery 31 is connected in parallel), and the first storage battery 31 is connected in series to the secondary side terminal pair 47, 48 of the first conversion circuit 40. The first conversion circuit 40 converts the power input from the first storage battery 31 to the primary side terminal pair 41, 42 and outputs it from the secondary side terminal pair 47, 48. The first conversion circuit 40 also converts the power input to the secondary side terminal pair 47, 48 and outputs it from the primary side terminal pair 41, 42. That is, the first conversion circuit 40 is a bidirectional conversion circuit.

[0033] The second storage battery module 60 has a similar configuration to the first storage battery module 30, and includes a second storage battery 61 (storage battery), a second current sensor 63 (current sensor), a second drive circuit 65 (drive circuit), a second conversion circuit 70, relays 70a, 70b, etc. The second conversion circuit 70 (conversion circuit) has a similar configuration to the first conversion circuit 40, and includes a primary side positive terminal 71 and a negative terminal 72, which are a primary side terminal pair, and a secondary side positive terminal 77 and a negative terminal 78, which are a secondary side terminal pair. The connection manner of these is also similar to that of the first storage battery module 30, so the above description of the first storage battery module 30 is used. Note that although the first storage battery module 30 and the second storage battery module 60 have configurations having similar functions, the ratings and withstand voltages of the respective configurations may be different from each other.

[0034] FIG. 2 shows an example of the first conversion circuit 40. The first conversion circuit 40 is a well-known center-tapped insulated DC-DC converter. The first conversion circuit 40 (first storage battery module 30) includes switching elements 43 to 46, 54, and 55, smoothing capacitors 50 and 57, a transformer 53, a reactor 56, voltage sensors 51 and 59, and current sensors 52 and 58. The switching elements 43 to 46, 54, and 55 are, for example, FETs and IGBTs (Insulated Gate Bipolar Transistors). The switching elements 43 to 46 form a full bridge circuit. A connection point between the switching element 43 and the switching element 44 and a connection point between the switching element 45 and the switching element 46 are connected to both ends of the primary coil of the transformer 53, respectively. The switching elements 54 and 55 are connected between both ends of the secondary coil of the transformer 53 and the reactor 56, respectively. The voltage sensor 51 (primary side voltage sensor) detects the voltage between the negative terminal 42 and the positive terminal 41 on the primary side, that is, the output voltage Vb (primary side voltage) of the first storage battery 31. The current sensor 52 (primary side current sensor) detects the input current Ii (primary side current) which is a current input (flowing) to the primary side circuit (primary side terminal pair 41, 42). The voltage sensor 59 (secondary side voltage sensor) detects the voltage between the negative terminal 48 and the positive terminal 47 on the secondary side, that is, the output voltage Vo (secondary side voltage) of the first conversion circuit 40. The current sensor 58 (secondary side current sensor) detects the current flowing through the reactor 56, that is, the output current Io (secondary side current flowing through the secondary side terminal pair 47, 48) of the first conversion circuit 40. The detection values ​​of the voltage sensors 51, 59 and the current sensors 52, 58 are input to the ECU 16.

[0035] The ECU 16 (control device) is configured as a microcomputer (computer) including, for example, a CPU, a ROM, a RAM, an input / output interface, etc. The ECU 16 controls the states of the relays 40a, 40b, 70a, 70b and the state of the load 21. Furthermore, the ECU 16 executes a control program applied to the power supply system 10 to realize the functions of a bus voltage setting unit 16a, a control unit 16b, etc.

[0036] The bus voltage setting unit 16a sets a bus voltage request value Vbus*, which is a voltage that is requested to be supplied from the buses 11 and 12 to the load 21. The bus voltage setting unit 16a sets the bus voltage request value Vbus* based on the state of the load 21.

[0037] The control unit 16b controls the output voltages Vo1 and Vo2 of the conversion circuits 40 and 70 so that the output voltages Vm1 and Vm2 of the storage battery modules 30 and 60 become the bus voltage request value Vbus* (approach the bus voltage request value Vbus*) during discharging. For example, the control unit 16b subtracts the first output voltage Vb1 of the first storage battery 31 from the bus voltage request value Vbus* to calculate the first output voltage request value Vo1* of the first conversion circuit 40. The control unit 16b calculates the first output current command value Io1* of the first conversion circuit 40 based on the first output voltage request value Vo1*. The control unit 16b calculates switching commands (duty command value Duty and drive signal G, which is an on-off pulse signal) in a plurality of control modes during discharging based on the first output current command value Io1* and the detection values ​​of the voltage sensors 51 and 59 and the current sensors 52 and 58. That is, the control unit 16b can execute a plurality of control modes that calculate a switching command based on an output current command value Io1* for the conversion circuit 40. The plurality of control modes include a peak current mode and an average current mode. The control unit 16b outputs a drive signal G to the first drive circuit 35 of the switching elements 43-46 to drive the switching elements 43-46 on and off. The plurality of control modes will be described later. Similarly, the control unit 16b controls the second output voltage Vo2 of the second conversion circuit 70 based on a second output current command value Io2* for the second conversion circuit 70.

[0038] Moreover, the control unit 16b controls the charging voltage or charging current of the storage batteries 31, 61 during charging. For example, the control unit 16b calculates a first output current command value Io1* as a charging current command value of the first conversion circuit 40 based on the state of charge (SOC: State Of Charge) of the storage battery 31. The control unit 16b calculates a switching command (a duty command value Duty and a driving signal G which is an on-off pulse signal) in a control mode during charging based on the first output current command value Io1* and the detection values ​​by the voltage sensors 51, 59 and the current sensors 52, 58. Then, the control unit 16b outputs the driving signal G to the first driving circuit 35 of the switching elements 54, 55 to drive the switching elements 54, 55 on and off. Similarly, the control unit 16b controls the charging voltage or charging current of the second storage battery 61 based on the second output current command value Io2* for the second conversion circuit 70.

[0039] 3 is a flowchart showing a procedure for switching the control mode. This series of processes is repeatedly executed at a predetermined cycle by the ECU 16 for each of the storage battery modules 30, 60. Here, the process for the first storage battery module 30 will be described as an example.

[0040] First, the output current command value Io* is obtained (S10), the input current sensor detection value is obtained (S11), and the output current sensor detection value is obtained (S12). The output current command value Io* is calculated by the control unit 16b as described above. The input current sensor detection value is the input current Ii detected by the current sensor 52. The output current sensor detection value is the output current Io detected by the current sensor 58.

[0041] Next, the calculation of switching timing commands (switching commands) according to a plurality of control modes is executed in parallel (S13, S14, S15).

[0042] In the process of S13, the switching timing command is calculated in the peak current mode during discharge. Since the peak current mode is a well-known control mode, a detailed description will be omitted and only an outline will be described. For example, the peak value of the input current Ii is set based on the acquired output current command value Io* and the turns ratio of the transformer 53, and the input current command value Ii* is calculated based on the peak value. The duty command value Duty is calculated based on the input current command value Ii*, the input current Ii detected by the current sensor 52, and the slope compensation value. The duty command value Duty (switching timing command) is a value indicating the time ratio of the on-period in a switching cycle when the switching element is driven on and off in a predetermined switching cycle by duty control. That is, in the peak current mode during discharge, the duty command value Duty is calculated based on the peak value of the input current of the first conversion circuit 40.

[0043] In the process of S14, the switching timing command is calculated by the average current mode during discharge. Since the average current mode is a well-known control mode, detailed description will be omitted and only an outline will be described. For example, a duty command value Duty (switching timing command) for the switching elements 43 to 46 is calculated based on the average value of the output current Io of the first conversion circuit 40 detected by the current sensor 58 and the output current command value Io*. The average current mode includes a continuous mode (continuous current mode) shown in FIG. 4(a) and a discontinuous mode (discontinuous current mode) shown in FIG. 4(b). As shown in FIG. 4(a), the output current Io is continuous in the continuous mode. On the other hand, as shown in FIG. 4(b), the discontinuous mode includes a period in which the output current Io becomes 0. As shown in FIG. 5, in the average current mode, a feedback correction term (FB term) by PI control, a feedforward correction term for the continuous mode (FF term for continuous), and a feedforward correction term for the discontinuous mode (FF term for discontinuous) are calculated. The continuous FF term during discharge is expressed by the continuous FF term=Vo / Vi, where the input voltage Vi and output voltage Vo of the first conversion circuit 40 are used. The input voltage Vi is detected by the voltage sensor 51, and the output voltage Vo is detected by the voltage sensor 59. The discontinuous FF term is expressed by √{2Lf(Io*)×(Vi-Vo) / ViVo}, where L is the reactance of the reactor 56, and f is the switching frequency in duty control. The smaller of the continuous FF term and the discontinuous FF term is adopted as the FF term. Then, the FB term and the FF term are added together to calculate the duty command value Duty in the average current mode.

[0044] In the process of S15, the switching timing command is calculated in the average current mode during charging. The average current mode during charging is similar to the average current mode during discharging, except that the duty command value Duty (switching timing command) for the switching elements 54, 55 is calculated, and the continuous FF term during charging=1-Vo / Vi is used.

[0045] Next, it is determined whether the output current command value Io* is equal to or greater than 0 (S16). If it is determined that the output current command value Io* is equal to or greater than 0 (S16: YES), it is determined whether the output current command value Io* is equal to or greater than a threshold value α (S17). The threshold value α is a current value that can determine that the current is in a large current region where high-speed response is required for controlling the discharge current, for example. If it is determined that the output current command value Io* is equal to or greater than the threshold value α (S17: YES), a drive signal G calculated based on a duty command value Duty calculated in the discharge peak current mode is output to the drive circuit 35 of the switching elements 43 to 46 (S18).

[0046] On the other hand, when it is determined in the judgment of S17 that the output current command value Io* is not equal to or greater than the threshold value α (S17: NO), it is determined whether or not the switching timing of the peak current mode is earlier than the switching timing of the average current mode during discharge (S19). For example, as shown in FIG. 6, the duty command value Duty calculated in the peak current mode and the duty command value Duty calculated in the average current mode during discharge, whichever is larger, is set as the duty command value Duty with the earlier switching timing (rising timing of the drive signal G). Then, the adopted duty command value Duty is converted into the drive signal G by, for example, RSFF (Reset Set Fop Flip). When it is determined in this judgment that the switching timing of the peak current mode is earlier than the switching timing of the average current mode during discharge (S19: YES), the process proceeds to S18.

[0047] On the other hand, when it is determined in the judgment of S19 that the switching timing of the peak current mode is not earlier than the switching timing of the average current mode during discharge (S19: NO), the drive signal G calculated based on the duty command value Duty calculated by the average current mode during discharge is output to the drive circuit 35 of the switching elements 43 to 46 (S20). That is, based on the output current command value Io* for the conversion circuit 40, two selectable duty command values ​​Duty are selected from the three calculated duty command values ​​Duty (switching commands) (S16, S17), and one of the two selectable duty command values ​​Duty is selected (S18 to S20). Specifically, when the output current command value Io* is equal to or greater than 0 (greater than 0), the duty command values ​​Duty of the peak current mode during discharge and the average current mode during discharge that are executable during discharge are selectable. Furthermore, when the output current command value Io* is not equal to or greater than 0 (is smaller than 0), the duty command value Duty of the charging average current mode that is executable during charging is made selectable.

[0048] When it is determined in S16 that the output current command value Io* is not equal to or greater than 0 (S16: NO), the drive signal G calculated based on the duty command value Duty calculated in the charging average current mode is output to the drive circuit 35 of the switching elements 54, 55 (S21). The process for the second storage battery module 60 is similar.

[0049] Figure 7 is a time chart showing the input current command value Ii* and the primary side input current Ii in the peak current mode during discharge. By using the peak current mode in the large current region, the discharge current can be controlled with high-speed response.

[0050] Figure 8 is a time chart showing the output current command value Io* and the secondary output current Io in the average current mode during discharge. By using the average current mode in the small current region, the discharge current can be precisely controlled.

[0051] FIG. 9 is a time chart showing the output current command value Io* and the output current Io. In the region where the output current command value Io* is equal to or greater than the threshold value α, a switching command for the peak current mode during discharge is selected. In the region where the output current command value Io* is smaller than the threshold value α and equal to or greater than 0, a switching command for the peak current mode during discharge or the average current mode during discharge is selected. At this time, the switching command for the peak current mode during discharge or the average current mode during discharge, whichever has the earlier switching timing, is selected. In the region where the output current command value Io* is less than 0, a switching command for the average current mode during charge is selected. At this time, in the small current region, the mode is discontinuous, and in the large current region, the mode is continuous. In any of the above control mode switching, the control mode is switched after the switching command is calculated in parallel in advance. Therefore, the fluctuation of the output current Io at the time of switching the control mode is suppressed, and the control accuracy of the output current Io is improved. Also, when switching between the discontinuous mode and the continuous mode, the fluctuation of the output current Io is suppressed by switching between the discontinuous FF term and the continuous FF term.

[0052] The present embodiment described above in detail has the following advantages.

[0053] The first conversion circuit 40 has the primary terminal pair 41, 42 connected in parallel to the storage battery 31 and the secondary terminal pair 47, 48 connected in series to the storage battery 31, and converts power by driving the switching elements 43 to 46, 54, 55. Therefore, the sum of the output voltage Vb of the storage battery 31 and the output voltage Vo of the first conversion circuit 40 becomes the output voltage Vm of the storage battery module 30 including the storage battery 31 and the first conversion circuit 40. Therefore, compared with a storage battery module in which the storage battery 31 is connected in parallel to the secondary terminal pair 47, 48 of the first conversion circuit 40, the output voltage Vo required for the first conversion circuit 40 can be reduced when the output voltage Vm is required for the storage battery module 30. Therefore, the rated voltage of the first conversion circuit 40 can be reduced, and the rated capacity of the first conversion circuit 40 can be reduced, so that the first conversion circuit 40 can be made smaller. The same applies to the second conversion circuit 70.

[0054] The control unit 16b controls the output current Io (charge / discharge current) of the storage battery 31 by driving the switching elements 43-46, 54, and 55 to turn on and off based on a switching command (duty command value Duty, drive signal G). The control unit 16b can execute a plurality of control modes that calculate a switching command based on an output current command value Io* for the first conversion circuit 40. Therefore, when controlling the output current Io of the storage battery 31, the control mode can be switched and executed according to a request to the power supply system 10.

[0055] The control unit 16b executes the calculation of switching commands according to a plurality of control modes in parallel. Therefore, regardless of which control mode is to be switched to, the switching commands in the plurality of control modes can be calculated in advance. Then, the control unit 16b selects one of the calculated switching commands and drives the switching elements 43 to 46, 54, and 55 based on the selected switching command. Therefore, regardless of which control mode switching command is selected, the switching elements 43 to 46, 54, and 55 can be quickly driven by the already calculated switching command. Therefore, it is possible to suppress the occurrence of a control response delay when switching the control mode, and to improve the control accuracy of the current.

[0056] The control unit 16b can execute a plurality of control modes when the storage battery 31 is discharged. Therefore, when the storage battery 31 is discharged, the control mode can be switched and executed according to a request to the power supply system 10. Then, the control unit 16b selects the switching command with the earliest switching timing (rising timing of the drive signal G) from among the plurality of switching commands calculated when the storage battery 31 is discharged. Therefore, when the switching command changes, the change in the switching command can be quickly reflected in the drive of the switching elements 43 to 46. Therefore, the response delay of the control can be made smaller.

[0057] The power supply system 10 includes a plurality of current sensors 52, 58 that detect currents in different paths in the first conversion circuit 40, and the plurality of control modes during discharge include control modes (peak current mode, average current mode) that calculate switching commands based on the detection values ​​of the plurality of current sensors 52, 58. With this configuration, the plurality of current sensors 52, 58 can detect currents in different paths in the first conversion circuit 40. Therefore, the control modes of different control methods can be executed based on the detection values ​​of the plurality of current sensors 52, 58.

[0058] The multiple current sensors 52, 58 include a current sensor 52 that detects an input current Ii input to the primary side terminal pair 41, 42 of the first conversion circuit 40, and a current sensor 58 that detects an output current Io output from the secondary side terminal pair 47, 48 of the first conversion circuit 40. With this configuration, it is possible to execute a peak current mode based on the peak value of the current and the input current Ii, or execute an average current mode based on the average value of the current and the output current Io.

[0059] The multiple control modes during discharge include a peak current mode in which a switching command is calculated based on a peak value of an input current input to the primary side terminal pair 41, 42 of the first conversion circuit 40, and an average current mode in which a switching command is calculated based on an average value of an output current output from the secondary side terminal pair 47, 48 of the first conversion circuit 40. With this configuration, the peak current mode can improve the control responsiveness of the discharge current of the storage battery 31, and the average current mode can improve the control accuracy of the discharge current of the storage battery 31.

[0060] The average current mode includes a continuous mode in which the discharge (charge) current is continuous during discharging (charging), and a discontinuous mode that includes a period in which the discharge (charge) current becomes zero during discharging (charging). The control unit 16b has a continuous FF term and a discontinuous FF term as correction terms for the switching command. With this configuration, it is possible to improve the control accuracy of the current when the continuous mode is executed and when the discontinuous mode is executed.

[0061] The control unit 16b calculates the FF term based on the input voltage Vi to the primary terminal pair 41, 42 and the output voltage Vo from the secondary terminal pair 47, 48. With this configuration, the FF term can be calculated appropriately, and the current control accuracy can be improved when the continuous mode is executed and when the discontinuous mode is executed. The input voltage Vi can also be calculated by multiplying the output voltage Vo by the turns ratio of the transformer 53.

[0062] Based on the output current command value Io* for the first conversion circuit 40, it is possible to narrow down the selectable switching commands from among the multiple switching commands calculated. Then, one switching command is selected from the selectable switching commands. Therefore, even if the number of multiple switching commands calculated is large, it becomes easier to select an appropriate switching command.

[0063] When the output current command value Io* for the first conversion circuit 40 is greater than 0, the control unit 16b can select, from among the multiple calculated switching commands, a switching command for a control mode that can be executed when discharging the storage battery 31. Also, when the output current command value Io* for the first conversion circuit 40 is less than 0, the control unit 16b can select, from among the multiple calculated switching commands, a switching command for a control mode that can be executed when charging the storage battery 31. With this configuration, the control mode for discharging and the control mode for charging can be smoothly switched, with the output current command value Io* becoming 0 as the boundary.

[0064] The switching command can be calculated based on the detection value of the primary side current sensor 52 included in the storage battery module 30. Therefore, it is not necessary to provide a dedicated current sensor just for detecting the input current Ii input to the primary side terminal pair 41, 42 of the first conversion circuit 40.

[0065] The above-mentioned advantageous effects can be achieved by causing the ECU 16 (computer) to execute the control program applied to the power supply system 10.

[0066] The above embodiment can be modified as follows: The same parts as those in the above embodiment are denoted by the same reference numerals and the description thereof will be incorporated herein.

[0067] The control unit 16b includes a voltage sensor 59 that detects the voltage (output voltage Vo) between the secondary terminal pair 47, 48 of the first conversion circuit 40, and the control unit 16b calculates a switching command based on the output voltage Vo detected by the voltage sensor 59. Here, the bus voltage Vbus can be calculated by adding the output voltage Vo of the conversion circuit 40 detected by the voltage sensor 59 to the output voltage Vb of the storage battery 31 detected by the voltage sensor 51. Therefore, the voltage sensor 13 that detects the bus voltage Vbus can be omitted. On the other hand, the output voltage Vo of the conversion circuit 40 can be calculated by subtracting the output voltage Vb of the storage battery 31 detected by the voltage sensor 51 from the bus voltage Vbus detected by the voltage sensor 13. In that case, the voltage sensor 59 can be omitted.

[0068] The control unit 16b can also use the current flowing through the first storage battery 31 detected by the first current sensor 33 (current sensor) and the current flowing through the second storage battery 61 detected by the second current sensor 63 (current sensor) to control the charging and discharging current.

[0069] For example, when the output current command value Io* decreases, the control unit 16b can select, from among the multiple calculated switching commands, the switching command with the earliest falling timing of the drive signal G as the switching command with the earliest switching timing.

[0070] In the flowchart of FIG. 3, the process of S19 may be omitted, and if it is determined in S17 that the output current command value Io* is not equal to or greater than the threshold value α (S17: NO), the process may proceed to S20.

[0071] In Figure 5, the FF term can be omitted.

[0072] As shown in FIG. 9, when the storage battery 31 is charged, the control unit 16b executes only the charging average current mode. That is, when the storage battery 31 is charged, the control unit 16b switches between the discontinuous FF term (discontinuous mode) and the continuous FF term (continuous mode), but does not switch the control mode. Therefore, when the current output current command value Io* is smaller than 0 and only the charging average current mode is executed, the control unit 16b may execute only the calculation of the switching command by the charging average current mode without executing the calculation of the switching command by the discharging peak current mode and the discharging average current mode in parallel. That is, when only a predetermined control mode is executed at the current output current command value Io* for the first conversion circuit 40, the control unit 16b may prioritize the execution of only the calculation of the switching command by the predetermined control mode without executing the calculation of the switching command by the multiple control modes in parallel. According to this configuration, when only a predetermined control mode is executed at the current output current command value Io* for the first conversion circuit 40, it is possible to omit the calculation of the unnecessary switching command. Therefore, the processing load on the control unit 16b (ECU 16) can be reduced.

[0073] As shown in Fig. 10, a switching command can be selected so that the input current Ii in the average current mode is upper-limit-guarded by the input current command value Ii* in the peak current mode. With this configuration, even if an overcurrent occurs due to biased magnetization when the average current mode is being executed, the overcurrent can be suppressed by the switching command for the peak current mode that is calculated in advance in parallel. During charging, in addition to the average current mode during charging, the peak current mode during charging can also be executed. The peak current mode during charging is similar to the peak current mode during discharging, except that a duty command value Duty (switching timing command) for the switching elements 54, 55 is calculated. Then, similar to the processing of S17 to S20 in the flowchart of Fig. 3, it is possible to switch between outputting a drive signal G calculated based on a duty command value Duty calculated in the peak current mode during charging and outputting a drive signal G calculated based on a duty command value Duty calculated in the average current mode during charging.

[0074] 11, a predetermined storage battery module 120 including a storage battery 121 but no conversion circuit may be connected to the buses 11 and 12. The predetermined storage battery module 120 includes a voltage sensor 121a that detects the voltage of the storage battery 121, and relays 120a and 120b that connect and disconnect the predetermined storage battery module 120 to the buses 11 and 12, respectively. The storage battery modules 30 and 60 also include voltage sensors 31a and 61a, relays 40a and 40b, and relays 70a and 70b, respectively. With this configuration, power can be supplied from the predetermined storage battery module 120 to the buses 11 and 12. In addition, the storage battery modules 30 and 60 each including the conversion circuits 40 and 70 can adjust the output voltages Vm1 and Vm2 of the storage battery modules 30 and 60 to the output voltage Vmb=400[V] of the predetermined storage battery module 120 by controlling the output voltages Vo1 and Vo2 of the conversion circuits 40 and 70, which are added to the output voltages Vb1 and Vb2 of the storage batteries 31 and 61, respectively. The control unit 16b can then execute the process of the flowchart of FIG. 3 for the storage battery modules 30 and 60. This can reduce the number of conversion circuits in the entire power supply system 210 while suppressing the flow of inrush current and circulating current between the storage battery modules 30 and 60 and the predetermined storage battery module 120. As a result, the power supply system 210 can be made smaller. The predetermined storage battery module 120 can be changed to, for example, the first storage battery module 30, and the process of the flowchart of FIG. 3 can be executed for the first storage battery module 30.

[0075] The load 21 may be, for example, a combination of an inverter and a motor generator (MG) (motor unit with inverter), and two or more of these may be connected in parallel to the buses 11 and 12. In this case, the number of storage battery modules connected to the buses 11 and 12 may be increased as the number of motor units with inverter increases. As shown in FIG. 12, the load 28 may be connected in parallel to the second storage battery 61 (storage battery) of the second storage battery module 60 (storage battery module). In this case, the charge amount of the second storage battery 61 can be reduced by supplying power from the second storage battery 61 to the load 28. Therefore, the second output voltage Vb2 of the second storage battery 61 of the second storage battery module 60 can be easily lowered below the first output voltage Vb1 of the first storage battery 31 of the first storage battery module 30. Therefore, it becomes easier to perform control to add the second output voltage Vo2 of the second conversion circuit 70 to the second output voltage Vb2 of the second storage battery 61 of the second storage battery module 60, and it becomes easier to adjust the second output voltage Vm2 of the second storage battery module 60 to the bus voltage request value Vbus*. In addition, the paths 22 to 24 and the relays 25 to 27 (switching circuits) can switch between a series connection and a parallel connection of the storage battery modules 30 and 60 to the buses 11 and 12. 13, the power supply system 210 may include a path 211 that connects a connection point N7 between the third conversion circuit 100 of the third storage battery module 90 and the relay 90a, and a connection point N8 between the first storage battery 31 of the first storage battery module 30 and the relay 40b. Furthermore, the power supply system 210 may include a path 213 that connects a connection point N9 between the first conversion circuit 40 of the first storage battery module 30 and the relay 40a, and a connection point N10 between the second storage battery 61 of the second storage battery module 60 and the relay 70b. The path 211 is provided with a relay 212 (switch) that disconnects and connects the path 211. The path 213 is provided with a relay 214 (switch) that disconnects and connects the path 213. The relays 212 and 214 are controlled by the ECU 16. The paths 211 and 213 and the relays 212 and 214 form a switching circuit. That is, the power supply system 210 may include three or more storage battery modules (a plurality of storage battery modules), and the switching circuit may switch the three or more storage battery modules between series connection and parallel connection with the buses 11 and 12.

[0076] As shown in Fig. 14, in the first conversion circuit 40 (conversion circuit), the switching elements 54, 55 in Fig. 2 may be connected between the transformer 53 and the negative terminal 48. With this configuration, it is possible to achieve the same effects as the first conversion circuit 40 in Fig. 2. The same is true for the second conversion circuit 70 (conversion circuit).

[0077] 15, the first conversion circuit 40 (conversion circuit) may be a well-known insulated DC-DC converter including a non-center-tapped transformer 153 and a secondary full-bridge circuit composed of switching elements 143-146. The switching elements 143-146 are, for example, FETs and IGBTs (Insulated Gate Bipolar Transistors). The switching elements 143-146 are controlled by the ECU 16. In this case, the control unit 16b may also perform calculations of switching commands in a plurality of control modes in parallel, select one of the calculated switching commands, and drive the switching elements 43-46, 143-146 based on the selected switching command. The same applies to the second conversion circuit 70 (conversion circuit).

[0078] A resonant DC-DC converter may be used as the first conversion circuit 40 (conversion circuit). A non-insulated DC-DC converter such as a buck converter may be used as the first conversion circuit 40 (conversion circuit). In this case, the control unit 16b may perform the calculation of switching commands in a plurality of control modes in parallel, select one of the calculated switching commands, and drive the switching element based on the selected switching command. The same applies to the second conversion circuit 70 (conversion circuit).

[0079] The storage battery modules 30, 60 may be configured as shown in FIG. 16. That is, the positive electrode of the first storage battery 31 is connected to the bus 11. The positive electrode of the first storage battery 31 is connected to the positive terminal 41 of the primary side of the first conversion circuit 40, and the negative electrode of the first storage battery 31 is connected to the negative terminal of the first storage battery 31. The positive terminal 47 of the secondary side of the first conversion circuit 40 is connected to the negative electrode of the first storage battery 31. The negative terminal 48 of the secondary side of the first conversion circuit 40 is connected to the bus 12. In this case, the primary side terminal pair 41, 42 of the first conversion circuit 40 is connected in parallel to the first storage battery 31, and the secondary side terminal pair 47, 48 of the first conversion circuit 40 is connected in series to the first storage battery 31. With such a configuration, the same effects as those of the above embodiment can be achieved. The same applies to the second storage battery module 60 (storage battery module).

[0080] At least one of the functions of the bus voltage setting unit 16a and the control unit 16b of the ECU 16 can be realized by, for example, a power control ECU (Electronic Control Unit) that controls the power of the electric vehicle, or a vehicle control ECU (higher ECU) that controls the electric vehicle in an integrated manner. In addition, when the power supply system 10, 210 is used as, for example, a stationary power source, the functions of the bus voltage setting unit 16a and the control unit 16b of the ECU 16 can be realized by a stationary power source control ECU (control device) that controls the stationary power source.

[0081] The ECU 16 and the method described herein may be implemented by a special-purpose computer provided by configuring a processor and a memory programmed to execute one or more functions (instructions) embodied in a computer program. Alternatively, the ECU 16 and the method described herein may be implemented by a special-purpose computer provided by configuring a processor with one or more dedicated hardware logic circuits. Alternatively, the ECU 16 and the method described herein may be implemented by one or more special-purpose computers configured by a combination of a processor and a memory programmed to execute one or more functions and a processor configured with one or more hardware logic circuits. Also, the computer program may be stored in a computer-readable non-transitory tangible recording medium as instructions executed by the computer.

[0082] The above-described embodiment and each modified example may be combined to the extent possible.

[0083] Characteristic configurations extracted from the above-described embodiment and modified examples will be described below. [Configuration 1] a conversion circuit (40, 70) having a primary side terminal pair (41, 42, 71, 72) connected in parallel to the storage battery and a secondary side terminal pair (47, 48, 77, 78) connected in series to the storage battery, and converting power by driving switching elements (43-46, 54, 55, 143-146); and a control unit (16b) controlling a charge / discharge current of the storage battery by driving the switching elements on and off based on a switching command, The control unit is capable of executing a plurality of control modes for calculating the switching command based on an output current command value for the conversion circuit, executes the calculation of the switching command using the plurality of control modes in parallel, selects one of the calculated plurality of switching commands, and drives the switching element based on the selected switching command. [Configuration 2] The power supply system according to configuration 1, wherein the control unit is capable of executing a plurality of the control modes when discharging or charging the storage battery, and selects the switching command with the earliest switching timing from the plurality of switching commands calculated when discharging or charging the storage battery. [Configuration 3] A plurality of current sensors (19, 33, 52, 58, 63) are provided for detecting currents in different paths, The power supply system according to configuration 2, wherein the plurality of control modes during discharging or charging includes a control mode in which the switching command is calculated based on detection values ​​of at least two current sensors among the plurality of current sensors. [Configuration 4] The power supply system of configuration 3, wherein the multiple current sensors include at least two of a current sensor (52) that detects a primary current flowing through the primary terminal pair of the conversion circuit, a current sensor (58) that detects a secondary current flowing through the secondary terminal pair of the conversion circuit, and a current sensor (33, 63) that detects a current flowing through the storage battery. [Configuration 5] The power supply system according to any one of configurations 2 to 4, wherein the plurality of control modes during discharging or charging include a peak current mode in which the switching command is calculated based on a peak value of a current flowing through the primary side terminal pair of the conversion circuit, and an average current mode in which the switching command is calculated based on an average value of a current flowing through the secondary side terminal pair of the conversion circuit. [Configuration 6] At least one of the average current modes includes a continuous current mode in which a current flows continuously through the secondary terminal pair, and a discontinuous current mode including a period in which the current flows through the secondary terminal pair becomes zero, 6. The power supply system according to claim 5, wherein the control unit has a correction term for the switching command that differs between the continuous current mode and the discontinuous current mode. [Configuration 7] 7. The power supply system according to configuration 6, wherein the control unit calculates the correction term based on a primary-side voltage between the primary-side terminal pair and a secondary-side voltage between the secondary-side terminal pair. [Configuration 8] The power supply system according to any one of configurations 1 to 7, wherein, when only a predetermined control mode is executed for the current output current command value for the conversion circuit, the control unit does not execute the calculation of the switching command using the multiple control modes in parallel, but prioritizes executing only the calculation of the switching command using the predetermined control mode. [Configuration 9] The power supply system according to any one of configurations 1 to 8, wherein the control unit selects selectable switching commands from the calculated switching commands based on the output current command value for the conversion circuit, and selects one of the selectable switching commands. [Configuration 10] The power supply system of configuration 9, wherein the control unit is capable of selecting, from the plurality of calculated switching commands, a switching command of the control mode that can be executed when discharging the storage battery when the output current command value for the conversion circuit is greater than 0, and is capable of selecting, from the plurality of calculated switching commands, a switching command of the control mode that can be executed when charging the storage battery when the output current command value for the conversion circuit is smaller than 0. [Explanation of symbols]

[0084] 10...power supply system, 16...ECU, 16b...control unit, 31...first storage battery, 40...first conversion circuit, 41...positive terminal (primary side terminal pair), 42...negative terminal (primary side terminal pair), 47...positive terminal (secondary side terminal pair), 43...switching element, 44...switching element, 45...switching element, 46...switching element, 48...negative terminal (secondary side terminal pair), 54...switching element, 55...switching element, 61...second storage battery, 70...second conversion circuit, 71...positive terminal (primary side terminal pair), 72...negative terminal (primary side terminal pair), 77...positive terminal (secondary side terminal pair), 78...negative terminal (secondary side terminal pair), 143...switching element, 144...switching element, 145...switching element, 146...switching element, 210...power supply system.

Claims

1. a storage battery (31, 61); a conversion circuit (40, 70) having a primary side terminal pair (41, 42, 71, 72) connected in parallel to the storage battery and a secondary side terminal pair (47, 48, 77, 78) connected in series to the storage battery, and converting power by driving switching elements (43-46, 54, 55, 143-146); and a control unit (16b) controlling a charge / discharge current of the storage battery by driving the switching elements on and off based on a switching command, The control unit is capable of executing a plurality of control modes for calculating the switching command based on an output current command value for the conversion circuit, executes the calculation of the switching command using the plurality of control modes in parallel, selects one of the calculated plurality of switching commands, and drives the switching element based on the selected switching command.

2. 2. The power supply system according to claim 1, wherein the control unit is capable of executing a plurality of the control modes when discharging or charging the storage battery, and selects the switching command with the earliest switching timing from the plurality of switching commands calculated when discharging or charging the storage battery.

3. A plurality of current sensors (19, 33, 52, 58, 63) are provided for detecting currents in different paths, The power supply system according to claim 2 , wherein the plurality of control modes during discharging or charging include a control mode in which the switching command is calculated based on detection values ​​of at least two current sensors among the plurality of current sensors.

4. 4. The power supply system of claim 3, wherein the plurality of current sensors include at least two of a current sensor (52) that detects a primary side current flowing through the primary side terminal pair of the conversion circuit, a current sensor (58) that detects a secondary side current flowing through the secondary side terminal pair of the conversion circuit, and a current sensor (33, 63) that detects a current flowing through the storage battery.

5. The power supply system according to any one of claims 2 to 4, wherein the plurality of control modes during discharging or charging include a peak current mode in which the switching command is calculated based on a peak value of a current flowing through the primary side terminal pair of the conversion circuit, and an average current mode in which the switching command is calculated based on an average value of a current flowing through the secondary side terminal pair of the conversion circuit.

6. At least one of the average current modes includes a continuous current mode in which a current flows continuously through the secondary terminal pair, and a discontinuous current mode including a period in which the current flows through the secondary terminal pair becomes zero, The power supply system according to claim 5 , wherein the control unit has, as a correction term for the switching command, a correction term which differs between the continuous current mode and the discontinuous current mode.

7. The power supply system according to claim 6 , wherein the control unit calculates the correction term based on a primary-side voltage between the pair of primary-side terminals and a secondary-side voltage between the pair of secondary-side terminals.

8. The power supply system according to any one of claims 1 to 4, wherein when only a predetermined control mode is executed at the current output current command value for the conversion circuit, the control unit does not execute the calculation of the switching command using the multiple control modes in parallel, but prioritizes executing only the calculation of the switching command using the predetermined control mode.

9. The power supply system according to any one of claims 1 to 4, wherein the control unit selects a selectable switching command from among the calculated multiple switching commands based on the output current command value for the conversion circuit, and selects one of the selectable switching commands.

10. 10. The power supply system of claim 9, wherein the control unit is capable of selecting, from the plurality of calculated switching commands, a switching command of the control mode that can be executed when discharging the storage battery when the output current command value for the conversion circuit is greater than 0, and is capable of selecting, from the plurality of calculated switching commands, a switching command of the control mode that can be executed when charging the storage battery when the output current command value for the conversion circuit is less than 0.

11. a primary side current sensor (52) for detecting a primary side current flowing through the primary side terminal pair of the conversion circuit, and a secondary side current sensor (58) for detecting a secondary side current flowing through the secondary side terminal pair of the conversion circuit, the plurality of control modes includes a control mode in which the switching command is calculated based on detection values ​​of the primary side current sensor and the secondary side current sensor, The storage battery and the conversion circuit constitute a storage battery module (30, 60); The power supply system according to claim 1 , wherein the storage battery module includes the primary side current sensor.

12. a secondary side voltage sensor (59) for detecting a voltage between the secondary side terminal pair of the conversion circuit, and the control unit calculates the switching command based on the voltage detected by the secondary side voltage sensor. Alternatively, the power supply system according to claim 1 or 2 further comprises a bus voltage sensor (13) for detecting the voltage of a power supply bus (11, 12) to which the storage battery and the conversion circuit are connected, and the control unit calculates the switching command based on the voltage detected by the bus voltage sensor.

13. A control program applied to a power supply system (10, 210) including a storage battery (31, 61) and a conversion circuit (40, 70) in which a primary side terminal pair (41, 42, 71, 72) is connected in parallel to the storage battery and a secondary side terminal pair (47, 48, 77, 78) is connected in series to the storage battery, and which converts power by driving switching elements (43-46, 54, 55, 143-146), A process of controlling a charge / discharge current of the storage battery by driving the switching element based on a switching command; A process of executing a plurality of control modes for calculating the switching command based on an output current command value for the conversion circuit; A process of calculating the switching commands in the plurality of control modes in parallel, selecting one of the calculated plurality of switching commands, and driving the switching element based on the selected switching command; A control program for causing a computer (16) to execute the above.

Images