DESCRIPTION
`
`SWITCHING POWER SUPPLY DEVICE
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`This application is a continuation of U.S Application No. 16/072 138, which is a
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`U.S. national stage application of the PCT International Application No.
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`PCT/JP2017/003278 filed on January 31, 2017, which claims the benefit of
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`foreign priority of Japanese patent application No. 20 16052201 filed on March
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`16, 2016, the contents all of which are incorporated herein by reference.
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`TECHNICAL FIELD
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`10
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`[0001] The present disclosure relates to a switching power supply device.
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`BACKGROUND ART
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`[0002] Conventionally, a power supply device is known which converts
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`alternating-current
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`(AC) power from a multiphase AC power supply into
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`direct-current (DC) power (for example, see Patent Literature 1).
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`15
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`Citation List
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`Patent Literature
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`[0003] PTL 13 Japanese Patent Unexamined Publication No. 2012—10507
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`SUD/[MARY OF THE INVENTION
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`[0004] The present disclosure provides a switching power supply device which
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`20
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`is capable of reducing the cost and the size of the device.
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`[0005] A switching power supply device according to one embodiment of the
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`present disclosure includes a plurality of power supply circuits, a switching
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`circuit, an inrush current prevention circuit, and a control circuit.
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`The
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`plurality of power supply circuits include a first power supply circuit and a
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`25
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`second power supply circuit, and respectively correspond to a plurality of
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`phases of a multiphase AC power supply. The switching circuit switches a
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`phase to be connected to the second power supply circuit between a phase
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`1
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`

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`corresponding to the first power supply circuit and a phase corresponding to the
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`second power supply circuit. The inrush current prevention circuit is disposed
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`on a negative power line of the multiphase AC power supply, at a position closer
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`to the multiphase AC power supply than a connection point is. The plurality
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`of power supply circuits are connected with each other at the point. The
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`inrush current prevention circuit prevents inrush current. The control circuit
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`controls the switching circuit and the inrush current prevention circuit. The
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`control circuit causes the switching circuit to switch the phase to be connected
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`to the second power supply circuit to the phase corresponding to the first power
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`supply circuit, and causes the inrush current prevention circuit to function so
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`that initial charge of capacitors respectively included in the plurality of power
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`supply circuits is performed. Moreover, when the initial charge of the
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`capacitors is completed,
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`the control circuit causes the switching circuit to
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`switch the phase to be connected to the second power supply circuit to the
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`phase corresponding to the second power supply circuit, and causes the inrush
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`10
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`15
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`current prevention circuit to turn off.
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`[0006] According to the present disclosure, it is possible to provide a switching
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`power supply device capable of reducing the cost and the size of the device.
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`BRIEF DESCRIPTION OF DRAWINGS
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`20
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`[0007] FIG. 1 is a circuit diagram illustrating a case where a switching power
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`supply device according to a first exemplary embodiment of the present
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`disclosure is connected to a single-phase AC power supply.
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`FIG. 2 is a flowchart of an operation example of the switching power
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`supply device according to the first exemplary embodiment of the present
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`25
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`disclosure.
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`FIG. 3 is a circuit diagram illustrating a case where the switching
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`power supply device according to the first exemplary embodiment of the
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`2
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`

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`present disclosure is connected to a two-phase AC power supply.
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`FIG. 4 is a circuit diagram illustrating a case where the switching
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`power supply device according to the first exemplary embodiment of the
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`present disclosure is connected to the two-phase AC power supply.
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`FIG. 5 is a circuit diagram illustrating a configuration example of a
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`switching power supply device according to a comparative example described in
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`the first exemplary embodiment of the present disclosure.
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`FIG. 6 is a circuit diagram illustrating a case where a switching power
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`supply device according to a second exemplary embodiment of the present
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`disclosure is connected to a single-phase AC power supply.
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`FIG. 7 is a circuit diagram illustrating a case where the switching
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`power supply device according to the second exemplary embodiment of the
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`present disclosure is connected to a two-phase AC power supply.
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`FIG. 8 is a circuit diagram illustrating a case where the switching
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`power supply device according to the second exemplary embodiment of the
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`present disclosure is connected to the two-phase AC power supply.
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`FIG. 9 is a circuit diagram illustrating a case where the switching
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`power supply device according to the second exemplary embodiment of the
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`present disclosure is connected to a three-phase AC power supply.
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`FIG. 10 is a circuit diagram illustrating a case where the switching
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`power supply device according to the second exemplary embodiment of the
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`present disclosure is connected to the three-phase AC power supply.
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`FIG. 11 is a circuit diagram illustrating a configuration example of a
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`switching power supply device according to a comparative example described in
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`10
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`15
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`20
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`25
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`the second exemplary embodiment of the present disclosure.
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`DESCRIPTION OF EMBODIMENTS
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`

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`[0008] Prior to the description of embodiments of the present disclosure,
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`problems in a conventional technology will be briefly described.
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`In a case
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`where an inrush current prevention circuit for protecting the circuit from
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`inrush current is disposed for each phase in a power supply device which can
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`receive AC power from a multiphase AC power supply, the cost and size of the
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`power supply device are increased.
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`[0009] Hereinafter, respective embodiments of the present disclosure will be
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`described in detail with reference to the drawings.
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`[0010]
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`(First Exemplary Embodiment)
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`10
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`First, an example of a configuration of switching power supply device
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`100 according to the present embodiment will be described with reference to
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`FIG. 1. FIG. 1 is a circuit diagram illustrating a configuration example of
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`switching power supply device 100. Switching power supply device 100 may
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`be used in, for example, a charging device for vehicles (for example, electric
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`15
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`vehicles or hybrid vehicles), or in another device.
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`[0011] Switching power supply device 100 converts AC power from an AC
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`power supply into DC power, and outputs the DC power to high-voltage battery
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`20.
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`In FIG. 1, single-phase AC power supply 10a is illustrated as an example;
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`however, two-phase AC power supply 10b may be applied (see FIG. 3 and FIG.
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`20
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`4). High-voltage battery 20 is, for example, a battery for driving the motor of a
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`vehicle. An example of high-voltage battery 20 is a lithium ion battery.
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`[0012] Switching power supply device 100 includes power supply circuit 1a,
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`power supply circuit 1b, switching circuit 7, inrush current prevention circuit
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`12, and control circuit 17. Switching power supply device 100 includes two
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`25
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`power supply circuits 1a and 1b in order to correspond to the two-phase AC
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`power supply.
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`[0013] Each of power supply circuits 1a and 1b includes power supply filter 2,
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`4
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`AC/DC converter 3, and DC/DC converter 6.
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`[0014] Power supply filter 2 receives AC power from single-phase AC power
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`supply 10a or two-phase AC power supply 10b. Power supply filter 2 prevents
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`noise from entering the power supply line and flowing out of the power supply
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`line.
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`[0015] AC/DC converter 3 is disposed in a subsequent stage of power supply
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`filter 2. AC/DC converter 3 converts the AC power from power supply filter 2
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`into DC power, and outputs the DC power to DC/DC converter 6.
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`[0016] Moreover, AC/DC converter 3 includes3 electrolytic capacitor 4 on which
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`10
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`initial charge (pre-charge) is performed; and voltmeter 5 which measures the
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`voltage of electrolytic capacitor 4. The voltage value measured by voltmeter 5
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`is output to control circuit 17.
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`[0017] DC/DC converter 6 is disposed in a subsequent stage of AC/DC
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`converter 3. DC/DC converter 6 transforms the DC voltage from AC/DC
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`15
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`converter 3 to different DC voltage, and outputs the transformed DC voltage to
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`high-voltage battery 20.
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`[0018] Switching circuit 7 switches between a first mode in which only power
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`supply circuit 1a is driven when the AC power supply is single-phase AC power
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`supply 10a and a second mode in which power supply circuit 1a and power
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`20
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`supply circuit 1b are driven when the AC power supply is two-phase AC power
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`supply 10b.
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`In other words, switching circuit 7 is capable of switching the
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`phase to be connected to the power supply circuit (for example, 1b) which does
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`not correspond to a given phase (for example, L1) of the multiphase AC power
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`supply (for example, 10b), among a plurality of power supply circuits 1a and 1b,
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`25
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`between the given phase of the multiphase AC power supply and the phase (for
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`example, L2) corresponding to the power supply circuit.
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`[0019] Switching circuit 7 includes switching relay 8, coil 9, and drive circuit
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`5
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`

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`11. Drive circuit 11 switches between on and off of switching relay 8 in
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`response to a control signal from control circuit 17. This control signal
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`indicates turning on switching relay 8 or turning off switching relay 8.
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`[0020] The off-state of switching relay 8 refers to the state, as illustrated in
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`FIG. 1, where switching relay 8 is connected to one of power supply lines L1
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`branched at branch point n2.
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`In contrast, the on-state of switching relay 8
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`refers to the state, as illustrated in FIG. 4, where switching relay 8 is connected
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`to power supply line L2. Note that branch point n2 is a point (position) on the
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`positive power supply line L1 (first phase).
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`10
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`[0021] Inrush current prevention circuit 12 is disposed at a position closer to
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`single-phase AC power supply 10a than meeting point (connection point) n3 is.
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`The negative line of power supply circuit 1a and the negative line of power
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`supply circuit 1b are connected with each other at meeting point n3.
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`Inrush
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`current prevention circuit 12 limits inrush current. Meeting point n3 is a
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`15
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`point (position) on negative power supply line N.
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`[0022] Inrush current prevention circuit 12 includes; inrush current limiting
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`circuit 13 including a fuse and an inrush current limiting resistor; inrush
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`prevention relay 14; coil 15; and drive circuit 16. Drive circuit 16 switches
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`between on and off of inrush prevention relay 14 in response to a control signal
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`20
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`from control circuit 17 . This control signal indicates turning on inrush
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`prevention relay 14 or turning off inrush prevention relay 14. Note that FIG.
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`1 illustrates, as an example, a case where inrush prevention relay 14 is off.
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`FIG. 4 illustrates, as an example, a case where inrush prevention relay 14 is on.
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`[0023] Control circuit 17 is configured of, for example, a central processing
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`25
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`unit (CPU), a read only memory (ROM), and a random-access memory (RAM).
`
`[0024] For example, control circuit 1’7 causes switching circuit ’7 to switch the
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`phase to be connected to the power supply circuit (for example, 1b) which does
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`6
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`

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`not correspond to a given phase (for example, L1) to the given phase, and
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`causes inrush current prevention circuit 12 to function (turns off inrush
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`prevention relay 14) so that initial charge of electrolyte capacitors 4 included
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`respectively in the power supply circuits (for example, 1a, 1b) is performed.
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`When the initial charge of electrolyte capacitors 4 is completed, control circuit
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`17 causes switching circuit 7 to switch the phase to be connected to the power
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`supply circuit which does not correspond to the given phase to the phase (for
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`example, L2) corresponding to the power supply circuit, and turns off inrush
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`current prevention circuit 12 (turns on inrush prevention relay 14). Note that
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`10
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`the details of the control performed by control circuit 17 will be described later
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`with reference to FIG. 2.
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`[0025] An example of the configuration of switching power supply device 100
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`has been described above.
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`[0026] Next, an example of an operation of switching power supply device 100
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`15
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`will be described with reference to FIG. 2.
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`FIG. 2 is a flowchart of an
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`operation example of switching power supply device 100. The operation
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`described below starts, for example, when an AC power supply is powered on.
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`At this time, both switching relay 8 and inrush prevention relay 14 are off.
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`[0027] First, control circuit 17 determines the specification of the connected
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`20
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`AC power supply (step 8100).
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`Specifically, control circuit 17 determines
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`whether the AC power supply is single-phase AC power supply 10a or
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`two-phase AC power supply 10b.
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`[0028] Next, control circuit 17 performs control according to the determined
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`specification of the AC power supply such that charging (initial charge) of
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`25
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`electrolyte capacitor 4 of AC/DC converter 3 is performed (step 810 1).
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`[0029] Specifically, when the specification of
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`the AC power
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`supply is
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`single-phase AC power supply 10a, control circuit 17 performs control such that
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`7
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`

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`initial charge of electrolyte capacitor 4 of AC/DC converter 3 of power supply
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`circuit 1a is performed. At this time, switching relay 8 and inrush prevention
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`relay 14 are off as illustrated in FIG. 1.
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`[0030] Since inrush prevention relay 14 is off at this time, power supplied from
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`single-phase AC power supply 10a is supplied to power supply circuit 1a via
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`power supply line L1, and is also supplied to the inrush current limiting
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`resistor of inrush current limiting circuit 13. This allows charging (initial
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`charge) of electrolyte capacitor 4 of power supply circuit 1a to be performed
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`while preventing inrush current from flowing to power supply circuit 1a.
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`10
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`[0031]
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`In contrast, when the specification of the AC power supply is two-phase
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`AC power supply 10b, control circuit 17 performs control such that initial
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`charge of electrolyte capacitor 4 of AC/DC converter 3 in each of power supply
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`circuits 1a and 1b is performed. At this time, switching relay 8 and inrush
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`prevention relay 14 are off as illustrated in FIG. 3. Note that n1 in FIG. 3
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`15
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`refers to a neutral point.
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`[0032] Since switching relay 8 and inrush prevention relay 14 are off at this
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`time, power supplied from two-phase AC power supply 10b is supplied to power
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`supply circuit 1a and power supply circuit 1b via power supply line L1, and is
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`also supplied to the inrush current limiting resistor of inrush current limiting
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`circuit 13.
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`In other words, the circuit configuration is such that power supply
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`circuit 1a, power supply circuit 1b, and inrush current limiting circuit 13 are
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`connected between neutral point n1 and the first phase (L1) of two-phase AC
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`power supply 10b. The inrush current limiting resistor of inrush current
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`limiting circuit 13 allows charging (initial charge) of electrolyte capacitor 4 of
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`each of power supply circuits 1a and 1b to be performed while preventing
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`20
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`25
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`inrush current from flowing to power supply circuits 1a and 1b.
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`[0033] After the above control, control circuit 17 receives the voltage values of
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`8
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`

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`electrolytic capacitors 4 measured by voltmeters 5, respectively.
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`[0034] Next, control circuit 17 compares the voltage value received from each
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`of voltmeters 5 with a predetermined threshold value to determine whether the
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`initial charge of electrolytic capacitors 4 is completed (step 8102).
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`[0035] For example, when one of more of the voltage values from voltmeters 5
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`have not reached the threshold value, control circuit 17 determines that the
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`initial charge is not completed (step 81023 NO).
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`In this case, the flow returns
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`to step 8102.
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`[0036]
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`In contrast, for example, when the voltage values from all of voltmeters
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`10
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`5 have reached the threshold value, control circuit 17 determines that the
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`initial charge is completed (step 81021 YES).
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`In this case, the flow proceeds to
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`step 8103.
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`[0037] Here, when the specification of the AC power supply determined in step
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`8100 is single-phase AC power supply 10a (step 81031 single phase), control
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`15
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`circuit 17 turns on inrush prevention relay 14 (step 8105). At this time,
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`switching relay 8 is controlled to remain off. Then, only power supply circuit
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`1a is driven so that high-voltage battery 20 is charged (first mode).
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`[0038]
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`In contrast, when the specification of the AC power supply determined
`
`in step 8100 is multiphase (for example, two-phase AC power supply 10b) (step
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`20
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`81033 multiphase), control circuit 17 turns on switching relay 8 as illustrated in
`
`FIG. 4 (step 8104). Accordingly, the circuit configuration is such that power
`
`supply circuit 1a and power supply circuit 1b correspond to respective phases.
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`In other words, the circuit configuration is such that power supply circuit 1a is
`
`connected to neutral point n1 and the first phase (L1) of two-phase AC power
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`25
`
`supply 10b therebetween, and power supply circuit 1b is connected to neutral
`
`point n1 and the second phase (L2) of two-phase AC power supply 10b
`
`thereb etween.
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`

`

`[0039] Then, control circuit 17 turns on inrush prevention relay 14 (step 8105).
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`Accordingly, both power supply circuits 1a and 1b are driven so that
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`high-voltage battery 20 is charged (second mode).
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`[0040] An example of the operation of switching power supply device 100 has
`
`been described above.
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`[0041] FIG. 5 illustrates a configuration example of switching power supply
`
`device 101 as an example compared to the first exemplary embodiment. Note
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`that in FIG. 5, the structural elements which are the same as in FIG. 1, FIG. 3,
`
`and FIG. 4 are illustrated with the same reference numerals, and description of
`
`10
`
`such structural elements is omitted.
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`[0042] As illustrated in FIG. 5, in switching power supply device 101, inrush
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`current prevention circuits 12 are disposed both in power supply circuit 1a and
`
`power supply circuit 1b.
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`In such a configuration, a plurality of inrush current
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`prevention circuits 12 are required, which causes problems of increased cost
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`15
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`and size of switching power supply device 101.
`
`[0043]
`
`In contrast, in switching power supply device 100 according to the
`
`present embodiment, one inrush current prevention circuit 12 is disposed
`
`downstream of meeting point n3.
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`In both of the cases where the AC power
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`supply is single-phase AC power supply 10a and where the AC power supply is
`
`two-phase AC power supply 10b, inrush current prevention circuit 12 is used.
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`Accordingly, it is possible to reduce the cost and size of switching power supply
`
`device 100.
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`[0044]
`
`(Second Exemplary Embodiment)
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`Next, an example of a configuration of switching power supply device
`
`200 according to the present embodiment will be described with reference to
`
`FIG. 6. FIG. 6 is a circuit diagram illustrating a configuration example of
`
`switching power supply device 200.
`
`Switching power supply device 200
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`10
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`20
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`25
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`

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`includes three power supply circuits (1a to 1c) to correspond to a three-phase
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`AC power supply. Note that in FIG. 6, the structural elements which are the
`
`same as in FIG.
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`1 are illustrated with the same reference numerals, and
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`description of such structural elements is omitted.
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`[0045] Switching power supply device 200 may be used in, for example, a
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`charging device for vehicles (for example, electric vehicles or hybrid vehicles),
`
`or in another device.
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`10
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`15
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`[0046] Switching power supply device 200 is different from switching power
`
`supply device 100 illustrated in FIG.
`
`1 in that power supply circuit 1c and
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`switching circuit 7a are added.
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`Power supply circuit
`
`lc has the same
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`configuration as those of power supply circuits 1a and 1b. Moreover, switching
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`circuit 7a has the same configuration as that of switching circuit 7. On and off
`
`states of switching relay 8 are controlled by control circuit 17 .
`
`[0047] In a state where switching relay 8 of switching circuit 7a is off,
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`switching relay 8 is connected to one of power supply lines L1 branched at
`
`branch point n2.
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`In contrast, in a state where switching relay 8 of switching
`
`circuit 7a is on, switching relay 8 is connected to power supply line L3 as
`
`illustrated in FIG. 10.
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`[0048] Moreover, FIG. 6 illustrates, as an example, the case where switching
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`20
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`power supply device 200 is connected to single-phase AC power supply 10a.
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`However, switching power supply device 200 may be connected to two-phase AC
`
`power supply 10b (see FIG. ’7 and FIG. 8) or to three-phase AC power supply
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`10c (see FIG. 9 and FIG. 10).
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`[0049] Inrush current prevention circuit 12 is disposed at a position closer to
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`25
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`the AC power supply than meeting point (connection point) n3 is.
`
`The
`
`negative line of power supply circuit 1a, the negative line of power supply
`
`circuit 1b, and the negative line of power supply circuit 1c are connected with
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`11
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`

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`each other at meeting point n3.
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`Inrush current prevention circuit 12 limits
`
`inrush current.
`
`[0050] Note that in FIG. 6, the negative lines of power supply circuits 1a to 1c
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`are connected at one meeting point (connection point) n3. However, for
`
`example, a first connection point at which the negative line of power supply
`
`circuit 1a is connected with the negative line of power supply circuit 1b may be
`
`different from a second connection point at which the negative line of power
`
`supply circuit 1b is connected with the negative line of power supply circuit lc.
`
`In this case, inrush current prevention circuit 12 is disposed at a position closer
`
`to the AC power supply than the first connection point and the second
`
`connection point are.
`
`[0051]
`
`In the present embodiment, switching circuits 7 and 7a switch between
`
`the first mode and the second mode described in the first exemplary
`
`embodiment, and the third mode where power supply circuits 1a, 1b, and 1c are
`
`driven when the AC power supply is three-phase AC power supply 10c.
`
`[0052] An example of the configuration of switching power supply device 200
`
`has been described above.
`
`[0053] Next, an example of an operation of switching power supply device 200
`
`according to the present embodiment will be described with reference to FIG. 2.
`
`The operation described below starts, for example, when the AC power supply
`
`is powered on. At this time, switching relay 8 of switching circuit 7, switching
`
`relay 8 of switching circuit 7a, and inrush prevention relay 14 are off.
`
`[0054] First, control circuit 17 determines the specification of the connected
`
`AC power supply (step 8100).
`
`Specifically, control circuit 17 determines
`
`whether the AC power supply is single-phase AC power supply 10a, two-phase
`
`AC power supply 10b, or three-phase AC power supply 10c.
`
`[0055] Next, control circuit 17 performs control according to the determined
`
`12
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`10
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`15
`
`20
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`25
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`

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`specification of the AC power supply such that charging (initial charge) of
`
`electrolyte capacitor(s) 4 of AC/DC converter(s) 3 is performed (step S101).
`
`[0056] Specifically, when the specification of
`
`the AC power
`
`supply is
`
`single-phase AC power supply 10a, control circuit 17 performs control such that
`
`initial charge of electrolyte capacitor 4 of AC/DC converter 3 of power supply
`
`circuit 1a is performed. At this time, switching relay 8 of switching circuit 7,
`
`switching relay 8 of switching circuit 7a, and inrush prevention relay 14 are off
`
`as illustrated in FIG. 6.
`
`[0057] Since inrush prevention relay 14 is off at this time, power supplied from
`
`10
`
`single-phase AC power supply 10a is supplied to power supply circuit 1a via
`
`power supply line L1, and is also supplied to an inrush current limiting resistor
`
`of inrush current limiting circuit 13. This allows charging (initial charge) of
`
`electrolyte capacitor 4 of power supply circuit 1a to be performed while
`
`preventing inrush current from flowing to power supply circuit 1a.
`
`15
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`[0058] Moreover, when the specification of the AC power supply is two-phase
`
`AC power supply 10b, control circuit 17 performs control such that initial
`
`charge of electrolyte capacitor 4 of AC/DC converter 3 in each of power supply
`
`circuit 1a and power supply circuit 1b is performed. At this time, switching
`
`relay 8 of switching circuit '7, switching relay 8 of switching circuit 7a, and
`
`20
`
`inrush prevention relay 14 are off as illustrated in FIG. 7.
`
`[0059] Since switching relay 8 of switching circuit 7 and inrush prevention
`
`relay 14 are off at this time, power supplied from two-phase AC power supply
`
`10b is supplied to power supply circuit 1a and power supply circuit 1b Via power
`
`supply line L1, and is also supplied to the inrush current limiting resistor of
`
`25
`
`inrush current limiting circuit 13. This allows charging (initial charge) of
`
`electrolyte capacitor 4 of each of power supply circuit 1a and power supply
`
`circuit 1b to be performed while preventing inrush current from flowing to
`
`13
`
`

`

`power supply circuit 1a and power supply circuit 1b.
`
`[0060] Moreover, when the specification of the AC power supply is three-phase
`
`AC power supply 100, control circuit 17 performs control such that initial
`
`charge of electrolyte capacitor 4 of AC/DC converter 3 in each of power supply
`
`circuit 1a, power supply circuit 1b, and power supply circuit 1c is performed.
`
`At this time, switching relay 8 of switching circuit 7, switching relay 8 of
`
`switching circuit 7a, and inrush prevention relay 14 are off as illustrated in
`
`FIG. 9.
`
`[0061] Since switching relay 8 of switching circuit 7, switching relay 8 of
`
`switching circuit 7a, and inrush prevention relay 14 are off at this time, power
`
`supplied from three-phase AC power supply 10c is supplied to power supply
`
`circuit 1a, power supply circuit 1b, and power supply circuit 1c via power
`
`supply line L1, and is also supplied to the inrush current limiting resistor of
`
`inrush current limiting circuit 13.
`
`In other words, the circuit configuration is
`
`such that power supply circuit 1a, power supply circuit 1b, power supply circuit
`
`10
`
`15
`
`1c and inrush current limiting circuit 13 are connected to neutral point n1 and
`
`the first phase (L1) of three-phase AC power supply 10c therebetween.
`
`Accordingly, the inrush current limiting resistor of inrush current limiting
`
`circuit 13 allows charging (initial charge) of electrolyte capacitor 4 of each of
`
`20
`
`power supply circuit 1a, power supply circuit 1b, and power supply circuit 1c to
`
`be performed, while preventing inrush current from flowing to power supply
`
`circuit 1a, power supply circuit 1b, and power supply circuit 1c.
`
`[0062] After the above control, control circuit 17 receives the voltage value of
`
`each of electrolytic capacitor 4 measured by respective one of voltmeters 5.
`
`25
`
`[0063] The operation of step 8102 is similar to that in the first exemplary
`
`embodiment above, and thus, description of the operation of step 8102 is
`
`omitted here.
`
`14
`
`

`

`[0064] When the specification of the AC power supply determined in step 8100
`
`is single-phase AC power supply 10a (step 51031 single phase), control circuit
`
`17 turns on inrush prevention relay 14 (step 8105). At
`
`this time, both
`
`switching relay 8 of switching circuit 7 and switching relay 8 of switching
`
`circuit 7a are controlled to remain off. Then, only power supply circuit 1a is
`
`driven so that high-voltage battery 20 is charged (first mode).
`
`[0065] When the specification of the AC power supply determined in step 8100
`
`is two-phase AC power supply 10b (step 81033 multiphase), control circuit 17
`
`turns on switching relay 8 of switching circuit 7 (step 8104) and turns on
`
`10
`
`inrush prevention relay 14 (step 8105), as illustrated in FIG. 8. As illustrated
`
`in FIG. 8, switching relay 8 of switching circuit 7a is controlled to remain off.
`
`Accordingly, both power supply circuits 1a and 1b are driven so that
`
`high-voltage battery 20 is charged (second mode).
`
`[0066] When the specification of the AC power supply determined in step 8100
`
`15
`
`is three-phase AC power supply 10c (step 81031 multiphase), control circuit 17
`
`turns on both switching relay 8 of switching circuit 7 and switching relay 8 of
`
`switching circuit 7a, as illustrated in FIG. 10 (step 8104). Accordingly, the
`
`circuit configuration is such that power supply circuit 1a, power supply circuit
`
`1b, and power supply circuit 1c correspond to respective phases.
`
`In other
`
`20
`
`words,
`
`the circuit configuration is such that power supply circuit 1a is
`
`connected to neutral point n1 and the first phase (L 1) of three-phase AC power
`
`supply 100 therebetween, power supply circuit 1b is connected to neutral point
`
`n1 and the second phase (L2) of three-phase AC power supply 10c therebetween,
`
`and power supply circuit 1c is connected to neutral point n1 and the third phase
`
`25
`
`(L3) of three-phase AC power supply 10c therebetween.
`
`[0067] Then, control circuit 17 turns on inrush prevention relay 14 (step 8105).
`
`Accordingly, all of power supply circuits 1a, 1b, and 1c are driven so that
`
`15
`
`

`

`high-voltage battery 20 is charged (third mode).
`
`[0068] An example of the operation of switching power supply device 200 has
`
`been described above.
`
`[0069] FIG. 11 illustrates a configuration example of switching power supply
`
`device 201 as an example compared to the second exemplary embodiment.
`
`Note that in FIG. 11, the structural elements which are the same as in FIG. 6 to
`
`FIG. 10 are illustrated with the same reference numerals, and description of
`
`such structural elements is omitted.
`
`[0070] As illustrated in FIG. 11, in switching power supply device 201, inrush
`
`10
`
`current prevention circuits 12 are disposed in power supply circuit 1a, power
`
`supply circuit 1b, and power supply circuit 1c,
`
`respectively.
`
`In such a
`
`configuration, a plurality of inrush current prevention circuits 12 are required,
`
`which causes problems of increased cost and size of switching power supply
`
`device 201.
`
`15
`
`[0071]
`
`In contrast, in switching power supply device 200 according to the
`
`present embodiment, one inrush current prevention circuit 12 is disposed
`
`downstream of meeting point n3.
`
`In all of the cases where the AC power
`
`supply is single-phase AC power supply 10a, where the AC power supply is
`
`two-phase AC power supply 10b, and where the AC power supply is three-phase
`
`20
`
`AC power
`
`supply 10c,
`
`inrush current prevention circuit
`
`12
`
`is used.
`
`Accordingly, it is possible to reduce the cost and size of switching power supply
`
`device 200.
`
`[0072] Although embodiments of the present disclosure have been described
`
`above, the present disclosure is not limited to those embodiments. Various
`
`25
`
`modifications are possible within the scope of the essence of the present
`
`disclosure.
`
`[0073] For example,
`
`in the above embodiments,
`
`the example has been
`
`16
`
`

`

`described where power supply circuit 1a, power supply circuit 1b, and power
`
`supply circuit 1c are connected to L1 (first phase) when initial charge of the
`
`capacitors is performed. However, the present disclosure is not limited to such
`
`an example.
`
`It may be that power supply circuit 1a, power supply circuit 1b,
`
`and power supply circuit 1c are connected to L2 (second phase) or L3 (third
`
`phase) when initial charge of the capacitors is performed.
`
`In other words,
`
`when initial charge of the capacitors is performed, it is only required that a
`
`plurality of power supply circuits (1a to lc) are connected between a given
`
`phase and neutral point n1.
`
`10
`
`INDUSTRIAL APPLI CABILITY
`
`[0074] The present disclosure can be applied to a power supply device which
`
`converts AC power from an AC power supply into DC power.
`
`REFERENCE MARKS IN THE DRAWINGS
`
`15
`
`[0075] 1a, 1b, 1c
`
`power supply circuit
`
`power supply filter
`
`AC/DC converter
`
`electrolyte capacitor
`
`voltmeter
`
`DC/DC converter
`
`[\9
`
`3 4 5 6
`
`7, 7a
`
`switching circuit
`
`8
`
`switching relay
`
`9, 15
`
`coil
`
`20
`
`10a
`
`single-phase AC power supply
`
`25
`
`10b
`
`two-phase AC power supply
`
`10c
`
`three-phase AC power supply
`
`11, 16 drive circuit
`
`17
`
`

`

`12
`
`13
`
`14
`
`1’7
`
`inrush current prevention circuit
`
`inrush current limiting circuit
`
`inrush prevention relay
`
`control circuit
`
`20
`
`high-voltage battery
`
`100, 101, 200, 201
`
`switching power supply device
`
`18
`
`