초록 ▼

In a multiple power source system of the present invention that has an inverter connected to a reactance, such as three-phase coils in a motor, a high voltage battery is connected with a low voltage battery via one transistor (Tr2) and one diode (D2) included in the inverter and one phase coil (U-ph

In a multiple power source system of the present invention that has an inverter connected to a reactance, such as three-phase coils in a motor, a high voltage battery is connected with a low voltage battery via one transistor (Tr2) and one diode (D2) included in the inverter and one phase coil (U-phase coil) of the three-phase motor. The transistor Tr2 is turned on to make the electric current flow from the low voltage battery to the U-phase coil. The transistor Tr2 is subsequently turned off at a preset timing, so that the electric energy accumulated in the reactance, that is, the U-phase coil, flows through the diode D1 into the high voltage battery and thereby charges the high voltage battery. This arrangement enables the charging process from the low voltage battery to the high voltage battery without any complicated circuit structure for the voltage step-up. The three-phase motor may be unipolar driven with transistors connected to one side of the inverter. The arrangement of the present invention does not require any complicated structure, which undesirably increases the size of the multiple power source system, in order to ensure mutual supplement of the electric energy between electric systems having a large difference in voltage, for example, an electric system for driving a hybrid vehicle and an electric system for its control circuit.

대표청구항 ▼

1. A multiple power source system that supplies an electric power to a three-phase motor, said three-phase motor having Y-connected windings,said multiple power source system comprising: a first direct current power source; a power control circuit that is disposed between said first direct current p

1. A multiple power source system that supplies an electric power to a three-phase motor, said three-phase motor having Y-connected windings,said multiple power source system comprising: a first direct current power source; a power control circuit that is disposed between said first direct current power source and the Y-connected windings of said three-phase motor and has switching elements, which are switched on and off to supply an electric power output from said first direct current power source to said three-phase motor; a second direct current power source that is different from said first direct current power source; and a unit that prevents said first direct current power source from being charged with the electric power output from said second direct current power source while said switching elements are switched off, wherein one terminal of said second direct current power source is connected with a terminal of said first direct current power source having an identical polarity, and the other terminal of said second direct current power source is connected with a neutral point of the Y-connected windings in said three-phase motor, said multiple power source system further comprising: a charging control unit that controls the switching on and off of said switching elements and uses the windings of said three-phase motor to boost a voltage of said second direct current power source, and charges said first direct current power source with the boosted electric power output, when lack of the power supplied from said first direct current power source is detected, before said first direct current power source drives said three-phase motor.