Power supply device
A power supply device includes a storage battery, a capacitor unit connected to the storage battery, a power converter including three phases connected to the storage battery in parallel, a control device configured to control a switching on and off of switching elements included in the three phases respectively, a first connection terminal connected to a P terminal of a DC charger and located between first and second switching elements in any one of the three phases, and a second connection terminal connected to an N terminal of the DC charger and located between third and fourth switching elements in another one of the three phases.
1. A power supply device comprising:
a storage battery;
a capacitor unit in which a first capacitor and a second capacitor are connected in series between a positive terminal and a negative terminal of the storage battery;
a power converter including a U-phase, a V-phase, and a W-phase connected to the storage battery in parallel, the U-phase, the V-phase, and the W-phase being three-level inverters respectively, and each of the three-level inverters including:
a first switching element, a second switching element, a third switching element, and a fourth switching element connected in series;
a first diode of which a cathode is connected to a wiring connecting the first switching element and the second switching element and of which an anode is connected to a wiring connecting the first capacitor and the second capacitor; and
a second diode of which an anode connected to a wiring connecting the third switching element and the fourth switching element and of which a cathode is connected to a wiring connecting the first capacitor and the second capacitor, each of the three-level inverters being configured to selectively output, to a motor generator, a voltage of any one of three different voltage values by switching on and off each of the first switching element, the second switching element, the third switching element, and the fourth switching element;
a control device configured to control a switching on and off of each of the first switching element, the second switching element, the third switching element, and the fourth switching element of the power converter;
a first connection terminal electrically connected to a P terminal of a direct current charger and located between the first switching element and the second switching element in any one of the U-phase, the V-phase, and the W-phase; and
a second connection terminal electrically connected to an N terminal of the direct current charger and located on a wire that directly connects the third switching element and the fourth switching element in another one of the U-phase, the V-phase, and the W-phase.
2. The power supply device according to claim 1 , wherein a control mode of the control device includes a first charging mode in which the storage battery is charged without boosting power from the direct current charger and a second charging mode in which the storage battery is charged by boosting the power from the direct current charger.
3. The power supply device according to claim 2 , wherein, in the second charging mode, the control device is configured to control the switching on and off of each of the first switching element, the second switching element, the third switching element, and the fourth switching element of the power converter, such that the first capacitor and the second capacitor are alternately charged with the power from the direct current charger.
4. The power supply device according to claim 3 , wherein the control device is configured to:
when the first capacitor is charged with the power from the direct current charger,
switch on the first switching element in one phase having the first connection terminal from among the U-phase, the V-phase, and the W-phase, and the second switching element and the third switching element in another phase having the second connection terminal, and
switch off remaining switching elements, and
when the second capacitor is charged with the power from the direct current charger,
switch on the second switching element and the third switching element in the one phase having the first connection terminal from among the U-phase, the V-phase, and the W-phase, and the fourth switching element in the other phase having the second connection terminal, and
switch off remaining switching elements.
5. The power supply device according to claim 2 , wherein the control device is configured to, during the first charging mode,
maintain on-states of the first switching element in one phase having the first connection terminal from among the U-phase, the V-phase, and the W-phase, and the fourth switching element in another phase having the second connection terminal, and
maintain off-states of remaining switching elements.