Power supply device

Abstract

To provide a power supply device suppressing a large current flowing from a second power storage unit to a first power storage unit.SOLUTION: A power supply device performs one-side charge control for controlling a system main relay, a charging relay, a series connection relay, a parallel connection relay, and first and second neutral point relays so that only a first power storage unit is charged using an external DC power until the voltage of the first power storage unit becomes equal to or higher than the voltage of a second power storage unit before the first and second neutral point relays are turned on and a power storage device is charged using the external DC power.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present disclosure relates to a power supply device. [Background technology]

[0002] Conventionally, as this type of power supply device, one including a switching unit, a first input unit, and first and second relays has been proposed (see, for example, Patent Document 1). The switching unit switches between connecting the first power storage unit (first battery) and the second power storage unit (second battery) in series or in parallel. The first input unit receives power from an external charger connected to the external charger. The first relay is attached to a power line connecting the positive electrode of the first power storage unit and the positive electrode of the second power storage unit. The second relay is attached to a power line connecting the negative electrode of the first power storage unit and the negative electrode of the second power storage unit. In this device, when there is a difference in voltage between the first power storage unit and the second power storage unit, the first and second relays are turned on to connect the positive electrodes of the first and second power storage units to each other and to connect the negative electrodes of the first and second power storage units to each other. This suppresses the occurrence of a difference between the voltage of the first power storage unit and the voltage of the second power storage unit. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2030-150784 A Summary of the Invention [Problem to be solved by the invention]

[0004] Recently, a power supply device has been proposed that can switch between connecting the first and second power storage units in series and connecting the first and second power storage units in parallel. This power supply device includes a DC charging device having a charging power line, a charging relay, a series connection line, a series connection relay, a parallel connection line, a parallel connection relay, a neutral point line, first and second neutral point relays, and a second capacitor. The charging power line connects an external charging connector to a portion between the system main relay and the inverter of the power line. The charging relay is attached to the charging power line. The series connection line connects the first and second power storage units in series. The series connection relay is attached to the series connection line. The parallel connection line connects the first power storage unit side of the series connection relay of the series connection line to the second power storage unit side of the negative pole side relay of the negative pole side line of the power line and the pre-charge relay. The parallel connection relay is attached to the parallel connection line. The neutral point line connects the neutral point of the three-phase AC motor to the second power storage unit side of the series connection relay of the series connection line. The first neutral point relay is attached to the neutral point line. The second neutral point relay is attached to the neutral point line on the second power storage unit side of the first neutral point relay. The second capacitor is attached between the first neutral point relay and the second neutral point relay on the neutral point line and on the inverter side of the negative pole side relay of the negative pole side line of the power line. In this device, the positive pole side relay of the system main relay, the charging relay, the parallel connection relay, and the first and second neutral point relays are turned on, and the negative pole side relay of the system main relay, the pre-charging relay, and the series connection relay are turned off, thereby connecting the first power storage unit and the second power storage unit in parallel. In the power supply device, if the voltage of the first power storage unit is higher than the voltage of the second power storage unit before the first power storage unit and the second power storage unit are connected in parallel, a relatively large current flows from the second power storage unit to the first power storage unit via the inverter diode and the motor when the first power storage unit and the second power storage unit are connected in parallel. Such a current can cause problems in the wiring connecting the first power storage unit and the second power storage unit, and it is desirable to suppress this current.

[0005] A main object of the power supply device of the present disclosure is to prevent a large current from flowing from the second power storage unit to the first power storage unit. [Means for solving the problem]

[0006] The power supply device of the present disclosure employs the following measures to achieve the above-mentioned main object.

[0007] The power supply device of the present disclosure comprises: A power supply device for supplying power to an inverter having a plurality of switching elements and diodes connected in parallel in a reverse direction to each of the switching elements, the inverter driving a three-phase AC motor, a power storage device including a first power storage unit and a second power storage unit; a system main relay including: a positive-side relay attached to a positive-side line of a power line connecting the power storage device and the inverter; a negative-side relay attached to a negative-side line of the power line; and a precharge circuit in which a precharge resistor and a precharge relay are connected in series to bypass the negative-side relay; a first capacitor attached to the power line; a charging power line connecting an external charging connector to which external DC power is supplied and a portion of the power line between the system main relay and the inverter, a charging relay attached to the charging power line, a series connection line connecting the first power storage unit and the second power storage unit in series, a series connection relay attached to the series connection line, a parallel connection line connecting a side of the first power storage unit of the series connection relay on the series connection line and a side of the second power storage unit of the negative side line of the power line between the negative side relay and the precharge circuit, and a parallel connection relay attached to the parallel connection line. a neutral point line connecting a neutral point of the three-phase AC motor and a side of the series connection relay of the series connection line to the second power storage unit, a first neutral point relay attached to the neutral point line, a second neutral point relay attached to the neutral point line on the second power storage unit side of the first neutral point relay, and a second capacitor attached between the first neutral point relay and the second neutral point relay on the neutral point line and on the inverter side of the negative pole side relay and the precharge circuit of the negative pole side line of the power line, and a control device that performs one-sided charging control to control the system main relay, the charging relay, the series connection relay, the parallel connection relay, and the first and second neutral point relays so that only the first power storage unit is charged using the external DC power until a voltage of the first power storage unit becomes equal to or higher than a voltage of the second power storage unit, before turning on the first and second neutral point relays to charge the power storage device using the external DC power; The gist of the invention is to provide the following:

[0008] In the power supply device disclosed herein, before turning on the first and second neutral point relays to charge the power storage device using external DC power, one-sided charging control is performed to control the system main relay, the charging relay, the series connection relay, the parallel connection relay, and the first and second neutral point relays so that only the first power storage unit is charged using external DC power until the voltage of the first power storage unit becomes equal to or higher than the voltage of the second power storage unit. This prevents a bias voltage from being applied in the forward direction to the diodes of the inverter when the first and second neutral point relays are turned on after the one-sided charging control is performed, thereby preventing a large current from flowing from the second power storage unit through the diodes of the inverter and the motor. As a result, it is possible to prevent a large current from flowing from the first power storage unit to the second power storage unit.

[0009] Furthermore, in the power supply device disclosed herein, the control device may compare the voltage of the first power storage unit with the voltage of the second power storage unit before turning on the first and second neutral point relays to charge the power storage device using the external DC power, and execute the one-sided charging control when the voltage of the first power storage unit is less than the voltage of the second power storage unit. In this manner, the one-sided charging control can be executed after confirming that the voltage of the first power storage unit is less than the voltage of the second power storage unit, i.e., that a forward bias voltage is applied to a diode of the inverter when the first and second neutral point relays are turned on.

[0010] Furthermore, in the power supply device of the present disclosure, the control device may execute the one-sided charging control after controlling the system main relay, the charging relay, the series connection relay, the parallel connection relay, and the first and second neutral point relays so that both of the first and second capacitors are precharged before turning on the first and second neutral point relays to charge the power storage device using the external DC power. In this way, it is possible to more reliably prevent a large current from flowing from the second power storage unit to the first power storage unit after the first and second capacitors are precharged.

[0011] In the power supply device of the present disclosure, the one-sided charging control may be a control to turn on the charging relay, the positive side relay and the negative side relay of the system main relay, the parallel connection relay, and the second neutral point relay, and to turn off the pre-charging relay, the series connection relay, and the first neutral point relay of the system main relay. In this way, by turning on the charging relay, the positive side relay and the negative side relay of the system main relay, the parallel connection relay, and the second neutral point relay, and turning off the pre-charging relay, the series connection relay, and the first neutral point relay of the system main relay, only the first power storage unit can be charged. [Brief description of the drawings]

[0012] [Figure 1] 1 is a diagram showing an outline of the configuration of a power supply device 20 according to the present embodiment. [Diagram 2] FIG. 4 is an explanatory diagram for explaining the on / off state of each relay during a first charge. [Diagram 3] FIG. 4 is an explanatory diagram for explaining the on / off state of each relay during a second charge. [Figure 4] 10 is a flowchart showing an example of a post-connection processing routine executed by the control device 60. [Diagram 5] FIG. 11 is an explanatory diagram for explaining a current path in the power supply device 20 when step S110 is executed. [Figure 6] FIG. 11 is an explanatory diagram for explaining a current path in the power supply device 20 when step S140 is executed. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] An embodiment of the present disclosure will be described with reference to the drawings. Fig. 1 is a schematic diagram showing the configuration of a power supply device 20 according to the present embodiment. The power supply device 20 according to the embodiment is configured as a device that supplies power to an inverter 24 that drives a motor 22. The power supply device 20 includes a battery 26 as an electricity storage device, a system main relay 28, a first capacitor 34, a DC charging device 40, and a control device 60.

[0014] The motor 22 is configured as a well-known three-phase AC motor having a rotor with a permanent magnet attached to its outer surface and a stator with a three-phase coil wound around it. The inverter 24 is configured with six transistors T1 to T6 as switching elements and six diodes D1 to D6 connected in parallel to the transistors T1 to T6 in the opposite direction. The transistors T1 to T6 are arranged in pairs so that the inverter 24 is on the source side and the inverter 24 is on the sink side of the positive and negative bus bars shared by the inverter 24 as the power line 30. The transistors T1 to T6 are connected to the three-phase coils (U-phase, V-phase, W-phase) of the motor 22 at the connection points between the paired transistors. The inverter 24 forms a rotating magnetic field in the three-phase coils by controlling the ratio of the on-time of the paired transistors T1 to T6 while a voltage is acting between the positive and negative bus bars, thereby driving the motor 22 to rotate. A first smoothing capacitor 34 is connected to the power line 30.

[0015] The battery 26 includes a first cell 26a as a first power storage unit and a second cell 26b as a second power storage unit having the same inter-terminal voltage as the first cell 26a, and is connected to a power line 30. The first cell 26a and the second cell 26b are configured as, for example, lithium ion secondary batteries or nickel-metal hydride secondary batteries.

[0016] The system main relay 28 is connected to the power line 30. The system main relay 28 includes a positive side relay SMRB, a negative side relay SMRG, and a precharge circuit. The positive side relay SMRB is attached to a positive side line 30B of the power line 30. The negative side relay SMRG is attached to a negative side line 30G of the power line 30. In the precharge circuit, a precharge resistor R and a precharge relay SMRP are connected in series to bypass the negative side relay SMRG.

[0017] The DC charging device 40 includes an external charging connector 42, a charging power line 43, a charging relay 44, a series connection line 45, a series connection relay DCR, a parallel connection line 46, a parallel connection relay DCRNG, a neutral point line 47, first and second neutral point relays DCRN and DCRNB, and a second capacitor 48. The external charging connector 42 is connected to an external DC power source, and DC power (external DC power) is supplied from the outside. The charging power line 43 is connected to the external charging connector 42 and is connected between the system main relay 28 and the inverter 24 of the power line 30. The charging relay 44 is attached to the charging power line 43. The series connection line 45 connects the first battery 26a and the second battery 26b in series. The series connection relay DCR is attached to the series connection line 45. The parallel connection line 46 connects the first battery 26a side of the series connection relay DCR of the series connection line 45 to the second battery 26b side of the negative pole relay SMRG and pre-charge circuit of the negative pole line 30G of the power line 30. The parallel connection relay DCRNG is attached to the parallel connection line 46. The neutral point line 47 connects the neutral point of the motor 22 to the second battery 26b side of the series connection relay DCR of the series connection line 45. The first neutral point relay DCRN is attached to the neutral point line 47. The second neutral point relay DCRNB is attached to the neutral point line 47 on the second battery 26b side of the first neutral point relay DCRN. The second capacitor 48 is attached between the first neutral point relay DCRN and the second neutral point relay DCRNB on the neutral point line 47, and on the inverter 24 side of the negative side line 30G of the power line 30 relative to the negative side relay SMRG and the precharge circuit.

[0018] Although not shown, the control device 60 is configured as a microprocessor centered on a CPU, and in addition to the CPU, includes a ROM for storing a processing program, a RAM for temporarily storing data, a flash memory, an input / output port, a communication port, and the like. Signals from various sensors are input to the control device 60 via the input port. Examples of the signals input to the control device 60 include a rotational position θm from a rotational position detection sensor (e.g., resolver) 23 that detects the rotational position of the rotor of the motor 22, phase currents flowing through the three-phase coils (U-phase, V-phase, and W-phase) of the motor 22, a voltage VH from a voltage sensor 34a that detects the voltage of the first capacitor 34, and a voltage VL from a voltage sensor 48a that detects the voltage of the second capacitor 48. The control device 60 is also connected to a communication line for communicating with an external power source via the external charging connector 42.

[0019] Various control signals are output via an output port from the control device 60. Examples of signals output from the control device 60 include a switching control signal to the transistors T1 to T6 of the inverter 24, a drive control signal to the system main relay 28, a drive control signal to the charging relay 44, a drive control signal to the series connection relay DCR, a drive control signal to the parallel connection relay DCRNG, a drive control signal to the first neutral point relay DCRN, and a drive control signal to the second neutral point relay DCRNB.

[0020] When an external power source is connected to the external charging connector 42 of the DC charging device 40, the control device 60 inputs the voltage Vd of DC power supplied by the external power source (external DC voltage Vd). When the external DC voltage Vd is equal to the rated voltage V1 of the battery 26 when the first cell 26a and the second cell 26b are connected in series, the control device 60 charges the battery 26 by the first charging performed by the DC charging device 40, and when the external DC voltage Vd is 0.5 times the rated voltage V1, the control device 60 charges the battery 26 by the second charging performed by the DC charging device 40. FIG. 2 is an explanatory diagram for explaining the on / off state of each relay during the first charging. In the figure, the thick lines indicate the paths of current. In the first charging, as shown in Fig. 2, the control device 60 turns on the positive relay SMRB, the negative relay SMRG, the charging relay 44, and the series connection relay DCR of the system main relay 28, and turns off the parallel connection relay DCRNG, the precharge relay SMRP of the system main relay 28, and the first and second neutral relays DCRN and DCRNB. Therefore, in the first charging, the battery 26 is charged using the charging power line 43, the power line 30, and the series connection line 45 with the first cell 26a and the second cell 26b connected in series. Fig. 3 is an explanatory diagram for explaining the on / off state of each relay in the second charging. In the figure, the thick lines indicate the current paths. In the second charging, the control device 60 turns on the positive side relay SMRB, the negative side relay SMRG, the charging relay 44, the parallel connection relay DCRNG, and the first and second neutral relays DCRN and DCRNB of the system main relay 28, and turns off the precharge relay SMRP and the series connection relay DCR of the system main relay 28. Therefore, in the second charging, the first battery 26a and the second battery 26b are connected in parallel. Then, the first battery 26a is charged by a current path that runs from the positive side line of the charging power line 43 through the positive side line 30B of the power line 30, the first battery 26a, the parallel connection line 46, and the negative side line 30G of the power line 30, and returns to the negative side line of the charging power line 43.The second battery 26b is charged via a current path that runs from the positive line of the charging power line 43, through the positive line 30B of the power line 30, any one of diodes D1 to D3 of the inverter 24, the motor 22, the neutral line 47, the second battery 26b, the negative line 30G of the power line 30, and back to the negative line of the charging power line 43.

[0021] Next, the operation of power supply device 20 configured in this manner, particularly the operation before the second charging of battery 26 is performed, will be described. Fig. 4 is a flowchart showing an example of a post-connection processing routine executed by control device 60. Control device 60 executes this routine when an external power source is connected to external charging connector 42 and external DC voltage Vd is 0.5 times rated voltage V1. Note that before this routine is executed, system main relay 28, charging relay 44, series connection relay DCR, parallel connection relay DCRNG, first and second neutral point relays DCRN, DCRNB are all off.

[0022] When this routine is executed, the control device 60 turns on the parallel connection relay DCRNG, the positive side relay SMRB of the system main relay 28, and the second neutral relay DCRNB (step S100). Next, the control device 60 turns on the precharge relay SMRP of the system main relay 28 (step S110). FIG. 5 is an explanatory diagram for explaining the current paths in the power supply device 20 when step S110 is executed. In the figure, the thick solid line shows an outline of the first current path Pc1. The thick dashed line shows an outline of the second current path Pc2. When the parallel connection relay DCRNG, the positive side relay SMRB of the system main relay 28, the second neutral relay DCRNB, and the precharge relay SMRP of the system main relay 28 are turned on, the first current path Pc1 and the second current path Pc2 are formed as shown in the figure. The first current path Pc1 is a path that returns from the first battery 26a via the positive line 30B of the power line 30, the first capacitor 34, the negative line 30G of the power line 30, and the parallel connection line 46 to the first battery 26a. The first capacitor 34 is pre-charged (charged) by the current flowing through the first current path Pc1, and the voltage VH increases. The second current path Pc2 is a path that returns from the second battery 26b via the neutral point line 47, the second capacitor 48, and the negative line 30G of the power line 30 to the second battery 26b. The second capacitor 48 is pre-charged (charged) by the current flowing through the second current path Pc2, and the voltage VL increases.

[0023] Next, the control device 60 inputs the voltage VH from the voltage sensor 34a and the voltage VL from the voltage sensor 48a (step S120). Then, the control device 60 determines whether or not the voltage VH is equal to or higher than the voltage VL (step S130). When the voltage VH is equal to or higher than the voltage VL, the control device 60 turns on the negative side relay SMRG of the system main relay 28 (step S150), turns off the precharge relay SMRP of the system main relay 28 (step S160), and turns on the first neutral point relay DCRN (step S170). Then, the control device 60 performs the second charge (step S180) and ends this routine.

[0024] When the voltage VH is less than the voltage VL in step S130, the charging relay 44 is turned on (step S140). FIG. 6 is an explanatory diagram for explaining the current path in the power supply device 20 when step S140 is executed. In the figure, the thick solid line shows an outline of the third current path Pc3. When the charging relay 44 is turned on in a state in which the parallel connection relay DCRNG, the positive side relay SMRB of the system main relay 28, the second neutral relay DCRNB, and the precharge relay SMRP of the system main relay 28 are turned on, the third current path Pc3 is formed as shown in the figure. The third current path Pc3 is a current path that returns from the positive side line of the charging power line 43 to the negative side line of the charging power line 43 via the positive side line 30B of the power line 30, the first battery 26a, the parallel connection line 46, and the negative side line 30G of the power line 30. By forming the third current path Pc3 in this manner, one-sided charging, in which only the first battery 26a is charged, can be performed, thereby increasing the voltage VH.

[0025] When the charging relay 44 is thus turned on, in step S130, the process waits until the voltage VH becomes equal to or higher than the voltage VL (steps S130, S140). Then, when the voltage VH becomes equal to or higher than the voltage VL, the negative side relay SMRG of the system main relay 28 is turned on (step S150), the precharge relay SMRP of the system main relay 28 is turned off (step S160), and the first neutral point relay DCRN is turned on (step S170). Then, the control device 60 performs the second charging (step S180) and ends this routine. In this way, before turning on the first and second neutral point relays DCRN, DCRNB to charge the battery 26 using external DC power, one-sided charging control is performed to control the system main relay 28, the charging relay 44, the series connection relay DCR, the parallel connection relay DCRNG, and the first and second neutral point relays DCRN, DCRNB so that only the first battery 26a is charged using external DC power until the voltage VH of the first battery 26a becomes equal to or higher than the voltage VL of the second battery 26b, thereby preventing a bias voltage from being applied in the forward direction to the diodes D1-D3 of the inverter 24. This makes it possible to prevent a large current from flowing from the second battery 26b to the first battery 26a.

[0026] According to the power supply device 20 of the present disclosure described above, before the first and second neutral point relays DCRN, DCRNB are turned on to charge the battery 26 using external DC power, the voltage VH of the first battery 26a and the voltage VL of the second battery 26b are compared, and when the voltage VH of the first battery 26a is lower than the voltage VL of the second battery 26b, the system main relay 28, the charging relay 44, and the series connection relay 46 are controlled so that only the first battery 26a is charged using external DC power until the voltage VH of the first battery 26a becomes equal to or higher than the voltage VL of the second battery 26b. By performing one-sided charging control that controls the -DCR, the parallel connection relay DCRNG, and the first and second neutral point relays DCRN, DCRNB, it is possible to prevent a large current from flowing from the second battery 26b to the first battery 26a, and one-sided charging control can be performed after confirming that the voltage VH of the first battery 26a is less than the voltage VL of the second battery 26b, i.e., when the first and second neutral point relays DCRN, DCRNB are turned on, a forward bias voltage is applied to the diodes D1 to D3 of the inverter 24.

[0027] Furthermore, in the power supply device 20 of the present disclosure, before turning on the first and second neutral point relays DCRN, DCRNB to charge the battery 26 using external DC power, the system main relay 28, the charging relay 44, the series connection relay DCR, the parallel connection relay DCRNG, and the first and second neutral point relays DCRN, DCRNB are controlled so that the first and second capacitors 34, 48 are both precharged, and then one-sided charging control is executed, thereby more reliably preventing a large current from flowing from the second battery 26b to the first battery 26a after the first and second capacitors 34, 48 have been precharged.

[0028] In the power supply device 20 of the present disclosure, one-sided charging control is achieved by turning on the charging relay 44, the positive side relay SMRB and negative side relay SMRG of the system main relay 28, the parallel connection relay DCRNG, and the second neutral point relay DCRNB, and turning off the pre-charge relay SMRP, the series connection relay DCR, and the first neutral point relay DCRN of the system main relay 28, thereby enabling charging of only the first battery 26a.

[0029] In the above embodiment, before the first and second neutral point relays DCRN, DCRNB are turned on to charge the battery 26 using external DC power, the voltage VH of the first battery 26a is compared with the voltage VL of the second battery 26b, and one-sided charging control is executed when the voltage VH of the first battery 26a is less than the voltage VL of the second battery 26b. However, one-sided charging control may be executed by controlling the system main relay 28, the charging relay 44, the series connection relay DCR, the parallel connection relay DCRNG, and the first and second neutral point relays DCRN, DCRNB so that only the first battery 26a is charged using external DC power until the voltage VH of the first battery 26a becomes equal to or greater than the voltage VL of the second battery 26b, without comparing the voltage VH of the first battery 26a with the voltage VL of the second battery 26b.

[0030] In the above-described embodiment, before turning on the first and second neutral point relays DCRN, DCRNB to charge the battery 26 using external DC power, the system main relay 28, the charging relay 44, the series connection relay DCR, the parallel connection relay DCRNG, and the first and second neutral point relays DCRN, DCRNB are controlled so that both the first and second capacitors 34, 48 are precharged, and then one-sided charging control is executed. However, one-sided charging control may be executed without precharging the first and second capacitors 34, 48.

[0031] In the above-described embodiment, the power supply device 20 includes the battery 26 having the first cell 26a and the second cell 26b, but at least one of the first cell 26a and the second cell 26b may be a capacitor.

[0032] The correspondence between the main elements of the embodiment and the main elements of the invention described in the section on Means for Solving the Problems will be described. In the embodiment, the first battery 26a corresponds to the "first power storage unit", the second battery 26b corresponds to the "second power storage unit", the battery 26 corresponds to the "power storage device", the positive relay SMRB corresponds to the "positive relay", the negative relay SMRG corresponds to the "negative relay", the pre-charge resistor R corresponds to the "pre-charge resistor", the pre-charge relay SMRP corresponds to the "pre-charge relay", the system main relay 28 corresponds to the "system main relay", the first capacitor 34 corresponds to the "first capacitor", the charging power line 43 corresponds to the "charging power line", the charging relay 4 4 corresponds to the "charging relay", series connection line 45 corresponds to the "series connection line", series connection relay DCR corresponds to the "series connection relay", parallel connection line 46 corresponds to the "parallel connection line", parallel connection relay DCRNG corresponds to the "parallel connection relay", neutral point line 47 corresponds to the "neutral point line", first neutral point relay DCRN corresponds to the "first neutral point relay", second neutral point relay DCRNB corresponds to the "second neutral point relay", second capacitor 48 corresponds to the "second capacitor", DC charging device 40 corresponds to the "DC charging device", and control device 60 corresponds to the "control device".

[0033] Note that the correspondence between the main elements of the embodiment and the main elements of the invention described in the Means for Solving the Problem column does not limit the elements of the invention described in the Means for Solving the Problem column, since the embodiment is an example for specifically explaining the form for implementing the invention described in the Means for Solving the Problem column. In other words, the interpretation of the invention described in the Means for Solving the Problem column should be made based on the description in that column, and the embodiment is merely a specific example of the invention described in the Means for Solving the Problem column.

[0034] The above describes embodiments for implementing the present disclosure, but the present disclosure is not limited to these embodiments, and it goes without saying that the present disclosure can be implemented in various forms without departing from the gist of the present disclosure. [Industrial Applicability]

[0035] The present invention can be used in the power supply device manufacturing industry and the like. [Explanation of symbols]

[0036] 20 power supply device, 22 motor, 24 inverter, 26 battery, 26a first battery, 26b second battery, 28 system main relay, 30 power line, 30B positive side line, 30G negative side line, 34 first capacitor, 34a, 48a voltage sensor, 40 DC charging device, 42 external charging connector, 43 charging power line, 44 charging relay, 45 series connection line, 46 parallel connection line, 47 neutral line, 48 second capacitor, 60 control device, D1 to D6 diodes, DCR series connection relay, DCRN first neutral relay, DCRNB second neutral relay, DCRNG parallel connection relay, Pc1 first current path, Pc2 second current path, Pc3 third current path, R precharge resistor, SMRB positive side relay, SMRG negative side relay, SMRP Precharge relay, R precharge resistor, T1~T6 transistors.

Claims

1. A power supply device for supplying power to an inverter having a plurality of switching elements and diodes connected in parallel in a reverse direction to each of the switching elements, the inverter driving a three-phase AC motor, a power storage device including a first power storage unit and a second power storage unit; a system main relay including: a positive-side relay attached to a positive-side line of a power line connecting the power storage device and the inverter; a negative-side relay attached to a negative-side line of the power line; and a precharge circuit in which a precharge resistor and a precharge relay are connected in series to bypass the negative-side relay; a first capacitor attached to the power line; a charging power line connecting an external charging connector to which external DC power is supplied and a portion of the power line between the system main relay and the inverter, a charging relay attached to the charging power line, a series connection line connecting the first power storage unit and the second power storage unit in series, a series connection relay attached to the series connection line, a parallel connection line connecting a side of the first power storage unit of the series connection relay to a side of the second power storage unit of the negative side line of the power line between the negative side relay and the precharge circuit, and a parallel connection relay attached to the parallel connection line. a neutral point line connecting a neutral point of the three-phase AC motor and a side of the series connection relay of the series connection line to the second power storage unit, a first neutral point relay attached to the neutral point line, a second neutral point relay attached to the neutral point line on the second power storage unit side of the first neutral point relay, and a second capacitor attached between the first neutral point relay and the second neutral point relay on the neutral point line and on the inverter side of the negative pole side relay and the precharge circuit of the negative pole side line of the power line, and a control device that performs one-sided charging control to control the system main relay, the charging relay, the series connection relay, the parallel connection relay, and the first and second neutral point relays so that only the first power storage unit is charged using the external DC power until a voltage of the first power storage unit becomes equal to or higher than a voltage of the second power storage unit, before turning on the first and second neutral point relays to charge the power storage device using the external DC power; A power supply device comprising:

2. 2. The power supply device according to claim 1, The control device compares a voltage of the first power storage unit with a voltage of the second power storage unit before turning on the first and second neutral point relays to charge the power storage device using the external DC power, and performs the one-sided charging control when the voltage of the first power storage unit is lower than the voltage of the second power storage unit. power supply.

3. 3. The power supply device according to claim 1, The control device controls the system main relay, the charging relay, the series connection relay, the parallel connection relay, and the first and second neutral point relays so that both of the first and second capacitors are precharged before turning on the first and second neutral point relays to charge the power storage device using the external DC power, and then performs the one-sided charging control. power supply.

4. 3. The power supply device according to claim 1, The one-sided charging control is a control for turning on the charging relay, the positive side relay and the negative side relay of the system main relay, the parallel connection relay, and the second neutral point relay, and turning off the pre-charging relay, the series connection relay, and the first neutral point relay of the system main relay. power supply.

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