Power supply device

Abstract

The invention provides a power supply device. The power supply device turns on the first and second neutral point relays and charges the power storage device with external DC power. One-side charging control is performed in which the system main relay, the charging relay, the series connection relay, the parallel connection relay, and the first and second neutral point relays are controlled 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 greater than the voltage of the second power storage unit.

Description

Technical Field

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

[0002] In the past, as a power supply device of this type, an example having a switching unit, a first input unit, and first and second relays has been proposed (for example, refer to Japanese Patent Application Laid-Open No. 2020-150784). The switching unit switches the first power storage unit (first storage battery) and the second power storage unit (second storage battery) to be connected in series or in parallel. The first input unit is input with power from an external charger connected to an external charger. The first relay is mounted on a power line connecting the positive pole of the first power storage unit and the positive pole of the second power storage unit. The second relay is mounted on a power line connecting the negative pole of the first power storage unit and the negative pole 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 poles of the first and second power storage units to each other, and to connect the negative poles of the first and second power storage units to each other. Thus, the difference between the voltage of the first power storage unit and the voltage of the second power storage unit is suppressed. Summary of the invention

[0003] However, in recent years, a power supply device capable of switching between connecting the first power storage unit and the second power storage unit in series and connecting the first power storage unit and the second power storage unit in parallel has been proposed. The 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, a first and a second neutral point relay, and a second capacitor. The charging power line connects an external charging connector and a system main relay of the power line and an inverter. The charging relay is installed on the charging power line. The series connection line connects the first power storage unit and the second power storage unit in series. The series connection relay is installed on the series connection line. The parallel connection line connects the series connection line closer to the first power storage unit than the series connection relay and the negative side line of the power line closer to the negative side relay and the pre-charging relay closer to the second power storage unit. The parallel connection relay is installed on the parallel connection line. The neutral point line connects the neutral point of the three-phase AC motor and the series connection line on the side of the second power storage unit that is closer to the series connection relay. The first neutral point relay is installed on the neutral point line. The second neutral point relay is installed on the neutral point line on the side of the second power storage unit that is closer to the first neutral point relay. The second capacitor is installed 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 side line of the power line that is closer to the negative side relay. In this device, the positive 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 side relay of the system main relay, the pre-charging relay, and the series connection relay are turned off, so that the first power storage unit and the second power storage unit are connected in parallel. In a power supply device, when the voltage of the first power storage unit is greater 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 diode and the motor of the inverter when the first power storage unit and the second power storage unit are connected in parallel. Such a current may cause a malfunction in the wiring connecting the first power storage unit and the second power storage unit, and it is desired to suppress it.

[0004] A main object of the power supply device of the present disclosure is to suppress a large current from flowing from the second power storage unit to the first power storage unit.

[0005] The power supply device of the present disclosure adopts the following means to achieve the above-mentioned main object.

[0006] The power supply device disclosed herein is to supply power to an inverter having a plurality of switching elements and diodes connected in reverse parallel to the switching elements and driving a three-phase AC motor, wherein the power supply device comprises:

[0007] A power storage device having a first power storage unit and a second power storage unit;

[0008] a system main relay having a positive-side relay installed on a positive-side line of a power line connecting the power storage device and the inverter, a negative-side relay installed on a negative-side line of the power line, and a pre-charging circuit formed by connecting a pre-charging resistor and a pre-charging relay in series so as to bypass the negative-side relay;

[0009] a first capacitor installed on the power line;

[0010] A DC charging device, comprising: a charging power line, connecting an external charging connector to which external DC power is supplied and between the system main relay of the power line and the inverter; a charging relay, installed on 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, installed on the series connection line; a parallel connection line, connecting the series connection line closer to the first power storage unit than the series connection relay and the negative side line of the power line closer to the second power storage unit than the negative side relay and the pre-charging circuit; the parallel connection relay, installed on The parallel connection line; a neutral point line connecting the neutral point of the three-phase AC motor and the series connection line on the side closer to the second power storage unit than the series connection relay; a first neutral point relay installed on the neutral point line; a second neutral point relay installed on the neutral point line on the side closer to the second power storage unit than the first neutral point relay; and a second capacitor installed between the first neutral point relay and the second neutral point relay of the neutral point line and on the negative side line of the power line on the side closer to the inverter than the negative side relay and the pre-charging circuit, using the external DC power to charge the power storage device; and

[0011] A 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 to perform one-side charging control in a manner such that only the first storage unit is charged with the external DC power until the voltage of the first storage unit becomes equal to or higher than the voltage of the second storage unit, before the first and second neutral point relays are turned on to charge the storage device with the external DC power.

[0012] In the power supply device of the present disclosure, before the first and second neutral point relays are turned on to charge the power storage device with external DC power, a one-side 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 in such a way that only the first power storage unit is charged with 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. As a result, when the first and second neutral point relays are turned on after the one-side charging control is performed, a bias voltage is suppressed from being applied to the diode of the inverter in the forward direction, so that a large current is suppressed from flowing from the second power storage unit via the diode of the inverter and the motor. As a result, a large current can be suppressed from flowing from the first power storage unit to the second power storage unit.

[0013] In addition, in the power supply device disclosed in the present invention, the control device may also compare the voltage of the first storage unit with the voltage of the second storage unit before turning on the first and second neutral point relays to charge the storage device with the external DC power, and perform the single-sided charging control when the voltage of the first storage unit is lower than the voltage of the second storage unit.

[0014] Thus, after confirming that the voltage of the first power storage unit is lower than the voltage of the second power storage unit, that is, after confirming that a forward bias voltage is applied to the diode of the inverter when the first and second neutral point relays are turned on, the one-side charging control can be performed.

[0015] Furthermore, in the power supply device disclosed in the present invention, the control device may also control the system main relay, the charging relay, the series connection relay, the parallel connection relay, and the first and second neutral point relays in a manner to pre-charge the first and second capacitors together before turning on the first and second neutral point relays to charge the power storage device using the external DC power, and then perform the one-sided charging control.

[0016] Thus, after the first and second capacitors are precharged, it is possible to more reliably suppress a large current from flowing from the second power storage unit to the first power storage unit.

[0017] Moreover, in the power supply device disclosed in the present invention, the single-side charging control may also be a control that turns 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 turns off the pre-charging relay, the series connection relay, and the first neutral point relay of the system main relay.

[0018] Thus, 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

[0019] Features, advantages, and technical and industrial significance of exemplary embodiments of the present invention will be described below with reference to the accompanying drawings, in which like reference numerals represent like elements, and in which:

[0020] Figure 1 1 is a schematic structural diagram showing the structure of the power supply device according to the present embodiment.

[0021] Figure 2 It is an explanatory diagram for explaining the on / off state of each relay during the first charging.

[0022] Figure 3 It is an explanatory diagram for explaining the on / off state of each relay during the second charging.

[0023] Figure 4 : is a flowchart showing an example of a post-connection processing routine executed by the control device.

[0024] Figure 5 This is an explanatory diagram for explaining the current path in the power supply device when S110 is executed.

[0025] Figure 6 This is an explanatory diagram for explaining the current path in the power supply device when S140 is executed. DETAILED DESCRIPTION

[0026] Embodiments of the present disclosure will be described with reference to the drawings. Figure 1 1 is a schematic structural diagram showing the structure of the power supply device 20 of the present embodiment. The power supply device 20 of the embodiment is configured as a device that supplies power to the inverter 24 that drives the motor 22. The power supply device 20 includes a battery 26 as a power storage device, a system main relay 28, a first capacitor 34, a DC charging device 40, and a control device 60.

[0027] The motor 22 is configured as a known three-phase AC motor having a rotor having a permanent magnet attached to the outer surface and a stator having a three-phase coil wound thereon. The inverter 24 is configured by six transistors T1 to T6 as switching elements and six diodes D1 to D6 connected in reverse parallel to the transistors T1 to T6. The transistors T1 to T6 are arranged in pairs of two each so that the inverter 24 becomes the source side and the drain side with respect to the positive bus and the negative bus shared by the power line 30. The three-phase coils (U phase, V phase, W phase) of the motor 22 are connected to the connection points of the paired transistors T1 to T6. The inverter 24 controls the ratio of the conduction time of the paired transistors T1 to T6 in a state where a voltage acts between the positive bus and the negative bus, thereby forming a rotating magnetic field in the three-phase coil and rotating the motor 22. The first capacitor 34 for smoothing is connected to the power line 30.

[0028] The battery 26 includes a first battery 26a as a first power storage unit and a second battery 26b as a second power storage unit having the same terminal voltage as the first battery 26a, and is connected to the power line 30. The first battery 26a and the second battery 26b are configured as lithium ion secondary batteries or nickel-metal hydride secondary batteries, for example.

[0029] 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 installed on the positive-side line 30B of the power line 30. The negative-side relay SMRG is installed on the 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 so as to bypass the negative-side relay SMRG.

[0030] 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, a first and a second neutral point relays DCRN, DCRNB, and a second capacitor 48. The external charging connector 42 is connected to an external DC power source and supplies DC power (external DC power) 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 of the power line 30 and the inverter 24. The charging relay 44 is installed on 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 installed on the series connection line 45. The parallel connection line 46 connects the first battery 26a side of the series connection line 45 with the negative electrode side relay SMRG or the pre-charging circuit of the negative electrode side line 30G of the power line 30. The parallel connection relay DCRNG is installed on the parallel connection line 46. The neutral point line 47 connects the neutral point of the motor 22 with the second battery 26b side of the series connection line 45 with the series connection relay DCR. The first neutral point relay DCRN is installed on the neutral point line 47. The second neutral point relay DCRNB is installed on the second battery 26b side of the neutral point line 47 with the first neutral point relay DCRN. The second capacitor 48 is installed between the first neutral point relay DCRN and the second neutral point relay DCRNB of the neutral point line 47 and the negative electrode side relay SMRG and the pre-charging circuit of the negative electrode side line 30G of the power line 30 with the inverter 24 side.

[0031] Although not shown in the figure, the control device 60 is configured as a microprocessor centered on a CPU, and in addition to the CPU, it also has a ROM for storing a processing program, a RAM for temporarily storing data, a flash memory, an input / output port, a communication port, etc. Signals from various sensors are input to the control device 60 via the input port. As the signal input to the control device 60, for example, the rotation position θm from the rotation position detection sensor (e.g., a rotary transformer) 23 for detecting the rotation position of the rotor of the motor 22, the phase current flowing in the three-phase coil (U phase, V phase, W phase) of the motor 22, the voltage VH from the voltage sensor 34a for detecting the voltage of the first capacitor 34, and the voltage VL from the voltage sensor 48a for detecting the voltage of the second capacitor 48. In addition, the control device 60 is also connected to a communication line for communicating with an external power supply via the external charging connector 42.

[0032] Various control signals are outputted from the control device 60 via the output port. Examples of the signals outputted from the control device 60 include switch control signals for transistors T1 to T6 of the inverter 24, drive control signals for the system main relay 28, drive control signals for the charging relay 44, drive control signals for the series connection relay DCR, drive control signals for the parallel connection relay DCRNG, drive control signals for the first neutral point relay DCRN, and drive control signals for the second neutral point relay DCRNB.

[0033] When an external power source is connected to the external charging connector 42 of the DC charging device 40, the control device 60 inputs a voltage Vd of DC power supplied by the external power source (external DC voltage Vd). When the external DC voltage Vd is the rated voltage V1 of the battery 26 when the first battery 26a and the second battery 26b are connected in series, the control device 60 charges the battery 26 by the first charging of 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 of the DC charging device 40. Figure 2 FIG. 1 is an explanatory diagram for explaining the on / off state of each relay in the first charging. In the figure, the bold line indicates the path of the current. In the first charging, the control device 60 Figure 2 As shown, the positive electrode side relay SMRB, the negative electrode side relay SMRG, the charging relay 44, and the series connection relay DCR of the system main relay 28 are turned on, and the parallel connection relay DCRNG, the pre-charging relay SMRP of the system main relay 28, and the first and second neutral point relays DCRN and DCRNB are turned off. 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 in a state where the first battery 26a and the second battery 26b are connected in series. Figure 3: is an explanatory diagram for explaining the on / off state of each relay in the second charge. In the figure, the bold line represents the path of the current. In the second charge, 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 point relays DCRN and DCRNB of the system main relay 28, and turns off the pre-charge relay SMRP and the series connection relay DCR of the system main relay 28. Therefore, in the second charge, the first battery 26a and the second battery 26b are connected in parallel. In addition, the first battery 26a is charged by the current path 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 to the negative side line of the charging power line 43. The second battery 26b is charged by a current path that returns from the positive side line of the charging power line 43 via the positive side line 30B of the power line 30, any diode D1 to D3 of the inverter 24, the motor 22, the neutral point line 47, the second battery 26b, and the negative side line 30G of the power line 30 to the negative side line of the charging power line 43.

[0034] Next, the operation of the power supply device 20 configured as above, particularly the operation before the second charge of the storage battery 26 is performed, will be described. Figure 4 1 is a flowchart showing an example of a post-connection processing routine executed by the control device 60. The control device 60 executes this routine when the external DC voltage Vd is 0.5 times the rated voltage V1 when the external power supply is connected to the external charging connector 42. In addition, before executing this routine, 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 and DCRNB are all turned off.

[0035] 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 point relay DCRNB (S100). Next, the control device 60 turns on the precharge relay SMRP of the system main relay 28 (S110). Figure 51 is an explanatory diagram for explaining the current path in the power supply device 20 when S110 is executed. In the figure, the thick solid line represents the outline of the first current path Pc1. The thick dotted line represents the 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 point relay DCRNB, and the pre-charge relay SMRP of the system main relay 28 are turned on, as shown in the figure, the first current path Pc1 and the second current path Pc2 are formed. The first current path Pc1 is a path from the first battery 26a via the positive side line 30B of the power line 30, the first capacitor 34, the negative side 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) with the current flowing in the first current path Pc1, and the voltage VH rises. The second current path Pc2 is a path returning from the second battery 26b via the neutral point line 47, the second capacitor 48, and the negative electrode line 30G of the power line 30 to the second battery 26b. The second capacitor 48 is precharged (charged) by the current flowing in the second current path Pc2, and the voltage VL rises.

[0036] Next, the control device 60 inputs the voltage VH from the voltage sensor 34a and the voltage VL from the voltage sensor 48a (S120). Furthermore, the control device 60 determines whether the voltage VH is greater than the voltage VL (S130). When the voltage VH is greater than the voltage VL, the negative-side relay SMRG of the system main relay 28 is turned on (S150), the pre-charging relay SMRP of the system main relay 28 is turned off (S160), and the first neutral point relay DCRN is turned on (S170). Then, the control device 60 performs the second charging (S180), and ends this routine.

[0037] When voltage VH is lower than voltage VL in S130, charging relay 44 is turned on (S140). Figure 6 140 is an explanatory diagram for explaining the current path in the power supply device 20 when S140 is executed. In the figure, the thick solid line shows the outline of the third current path Pc3. When the charging relay 44 is turned on in the state where the parallel connection relay DCRNG, the positive side relay SMRB of the system main relay 28, the second neutral point relay DCRNB, and the pre-charging 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 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 to the negative side line of the charging power line 43. By forming the third current path Pc3 in this way, it is possible to perform single-side charging of charging only the first battery 26a, thereby increasing the voltage VH.

[0038] When the charging relay 44 is turned on in this way, the process waits until the voltage VH becomes equal to or higher than the voltage VL in S130 (S130, S140). 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 (S150), the pre-charging relay SMRP of the system main relay 28 is turned off (S160), and the first neutral point relay DCRN is turned on (S170). Then, the control device 60 performs the second charging (S180), and ends this routine. In this way, before the first and second neutral point relays DCRN and DCRNB are turned on to charge the storage battery 26 with 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 and DCRNB are controlled to perform one-side charging control in such a manner that only the first battery 26a is charged with 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 suppressing the forward bias voltage from being applied to the diodes D1 to D3 of the inverter 24. As a result, it is possible to suppress a large current from flowing from the second battery 26b to the first battery 26a.

[0039] According to the power supply device 20 of the present disclosure described above, before the first and second neutral point relays DCRN and DCRNB are turned on to charge the storage battery 26 with 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 and the charging relay 28 are controlled in such a manner that only the first battery 26a is charged with 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. The unilateral charging control of the relay 44, the series connection relay DCR, the parallel connection relay DCRNG, and the first and second neutral point relays DCRN and DCRNB can suppress a large current from flowing from the second battery 26b to the first battery 26a, and can perform unilateral charging control after confirming that the voltage VH of the first battery 26a is lower than the voltage VL of the second battery 26b, that is, after applying a forward bias voltage to the diodes D1 to D3 of the inverter 24 when the first and second neutral point relays DCRN and DCRNB are turned on.

[0040] Furthermore, in the power supply device 20 of the present invention, before the first and second neutral point relays DCRN and DCRNB are turned on to charge the battery 26 using external DC power, after 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 and DCRNB are controlled in a manner to pre-charge the first and second capacitors 34 and 48 together, single-sided charging control is performed, thereby being able to more reliably suppress a large current from flowing from the second battery 26b to the first battery 26a after the first and second capacitors 34 and 48 are pre-charged.

[0041] Moreover, in the power supply device 20 of the present disclosure, the single-side charging control is set to turn on the charging relay 44, the positive side relay SMRB and the negative side relay SMRG of the system main relay 28, the parallel connection relay DCRNG, and the second neutral point relay DCRNB, and turn off the pre-charging relay SMRP, the series connection relay DCR, and the first neutral point relay DCRN of the system main relay 28, so that only the first battery 26a can be charged.

[0042] In the above embodiment, before the first and second neutral point relays DCRN and DCRNB are turned on to charge the storage battery 26 with 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 one-side charging control is performed. However, without comparing the voltage VH of the first battery 26a and the voltage VL of the second battery 26b, the one-side charging control of 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 and DCRNB may be performed so that only the first battery 26a is charged with 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.

[0043] In the above embodiment, before the first and second neutral point relays DCRN and DCRNB are turned on to charge the storage battery 26 with 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 and DCRNB are controlled so as to precharge the first and second capacitors 34 and 48 together, and then the one-side charging control is performed. However, the one-side charging control may be performed without precharging the first and second capacitors 34 and 48.

[0044] In the above embodiment, the power supply device 20 includes the storage battery 26 including the first battery 26a and the second battery 26b. However, at least one of the first battery 26a and the second battery 26b may be a capacitor.

[0045] The correspondence between the main elements of the embodiment and the main elements of the invention described in the invention content is described. In the embodiment, the first battery 26a functions as a "first power storage unit", the second battery 26b functions as a "second power storage unit", the storage battery 26 functions as a "power storage device", the positive side relay SMRB functions as a "positive side relay", the negative side relay SMRG functions as a "negative side relay", the pre-charging resistor R functions as a "pre-charging resistor", the pre-charging relay SMRP functions as a "pre-charging relay", the system main relay 28 functions as a "system main relay", the first capacitor 34 functions as a "first capacitor", the charging power line 43 functions as a "charging power line", and the charging relay 44 functions as a "charging relay". " functions, the series connection line 45 functions as a "series connection line", the series connection relay DCR functions as a "series connection relay", the parallel connection line 46 functions as a "parallel connection line", the parallel connection relay DCRNG functions as a "parallel connection relay", the neutral point line 47 functions as a "neutral point line", the first neutral point relay DCRN functions as a "first neutral point relay", the second neutral point relay DCRNB functions as a "second neutral point relay", the second capacitor 48 functions as a "second capacitor", the DC charging device 40 functions as a "DC charging device", and the control device 60 functions as a "control device".

[0046] In addition, the correspondence between the main elements of the embodiment and the main elements of the invention described in the summary of the invention is used to specifically explain that the embodiment is an example of a method for implementing the invention described in the summary of the invention, and therefore does not limit the elements of the invention described in the summary of the invention. That is, the interpretation of the invention described in the summary of the invention should be based on the description of this part, and the embodiment is only a specific example of the invention described in the summary of the invention.

[0047] Although the embodiments for implementing the present disclosure have been described above, the present disclosure is not limited to such embodiments at all, and can of course be implemented in various forms within the scope not departing from the gist of the present disclosure.

[0048] The present invention can be used in the power supply device manufacturing industry and the like.

Claims

1. A power supply device for supplying electric power to an inverter having a plurality of switching elements and diodes connected in parallel with the switching elements in opposite directions and driving a three-phase AC motor, wherein: The power supply device comprises: A power storage device having a first power storage unit and a second power storage unit; a system main relay having a positive-side relay installed on a positive-side line of a power line connecting the power storage device and the inverter, a negative-side relay installed on a negative-side line of the power line, and a pre-charging circuit formed by connecting a pre-charging resistor and a pre-charging relay in series so as to bypass the negative-side relay; a first capacitor installed on the power line; A DC charging device, comprising: a charging power line, connecting an external charging connector to which external DC power is supplied and between the system main relay of the power line and the inverter; a charging relay, installed on 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, installed on the series connection line; a parallel connection line, connecting the series connection line closer to the first power storage unit than the series connection relay and the negative side line of the power line closer to the second power storage unit than the negative side relay and the pre-charging circuit; the parallel connection relay, installed on the A parallel connection line; a neutral point line connecting the neutral point of the three-phase AC motor and the series connection line on the side closer to the second power storage unit than the series connection relay; a first neutral point relay installed on the neutral point line; a second neutral point relay installed on the neutral point line on the side closer to the second power storage unit than the first neutral point relay; and a second capacitor installed between the first neutral point relay and the second neutral point relay of the neutral point line and on the negative side line of the power line on the side closer to the inverter than the negative side relay and the pre-charging circuit, the DC charging device uses the external DC power to charge the power storage device; as well as A control device that performs one-side charging control of the system main relay, the charging relay, the series connection relay, the parallel connection relay, the first neutral point relay, and the second neutral point relay in a manner such that only the first storage unit is charged with the external DC power until the voltage of the first storage unit becomes equal to or higher than the voltage of the second storage unit, before the first neutral point relay and the second neutral point relay are turned on to charge the storage device with the external DC power.

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

3. The power supply device according to claim 1 or 2, wherein: The control device performs the one-side charging control after controlling the system main relay, the charging relay, the series connection relay, the parallel connection relay, the first neutral point relay, and the second neutral point relay in a manner to pre-charge the first capacitor and the second capacitor together before turning on the first neutral point relay and the second neutral point relay to charge the power storage device using the external DC power.

4. The power supply device according to claim 1 or 2, wherein: The one-side charging control is a control that turns 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 turns off the pre-charging relay, the series connection relay, and the first neutral point relay of the system main relay.

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