Power supply device for electric vehicle
View Patent ↗The present invention provides a power supply device for an electric vehicle that allows highly efficient operation of a compressor inverter. A power supply device for motor vehicle 10 has: a main circuit 13 having a power source 11 , a DC-DC converter 18 , and a main inverter 17 that drives a main motor 12 ; an auxiliary circuit 15 having an auxiliary inverter 19 that drives an auxiliary motor 14 , a first electrical circuit 23 that is connected to the main circuit 13 on a primary side of the DC-DC converter 18 , a second electrical circuit 24 that is connected to the main circuit 13 on a secondary side of the DC-DC converter 18 , and a connection circuit 30 configured to be capable of selecting one of the first electrical circuit 23 and the second electrical circuit 24 as a path for supplying a direct current voltage to the auxiliary inverter 19 ; and a control device 16 that controls the connection circuit 30 when the main motor 12 is in power running operation so that switching between the first electrical circuit 23 and the second electrical circuit 24 is performed corresponding to a required voltage of the auxiliary inverter 19.
1. A power supply device for an electric vehicle intended to supply power from a direct current power source to a main motor and an auxiliary motor, the power supply device for an electric vehicle comprising:
a main circuit having a DC-DC converter that allows a direct current voltage of the power source to be stepped up and a main inverter that drives the main motor using an output from the DC-DC converter;
an auxiliary circuit having an auxiliary inverter that drives the auxiliary motor, a first electrical circuit that is connected to the main circuit on a primary side of the DC-DC converter, a second electrical circuit that is connected to the main circuit on a secondary side of the DC-DC converter, a connection circuit that is configured to be capable of selecting one of the first electrical circuit and the second electrical circuit as a path for supplying the direct current voltage to the auxiliary inverter; and
a control device that controls the connection circuit when the main motor is in power running operation so that the first electrical circuit is selected by the connection circuit when a required voltage of the auxiliary inverter is lower than the direct current voltage of the power source while the second electrical circuit is selected by the connection circuit when the required voltage of the auxiliary inverter is equal to or higher than the direct current voltage of the power source.
2. The power supply device for an electric vehicle according to claim 1 , wherein
the control device controls the connection circuit when the main motor is in regenerative operation so that the second electrical circuit is selected by the connection circuit.
3. The power supply device for an electric vehicle according to claim 1 , wherein
the control device controls the DC-DC converter so that the direct current voltage stepped up in the DC-DC converter should be equal to or higher than the required voltage of the auxiliary inverter when the required voltage of the auxiliary inverter is equal to or higher than the direct current voltage of the power source as well as the required voltage of the auxiliary inverter is equal to or higher than the required voltage of the main inverter.
4. The power supply device for an electric vehicle according to claim 1 , wherein
the main motor is a drive motor used for running,
the main inverter is a drive motor inverter,
the auxiliary motor is a compressor motor for driving a vehicle air conditioner, and
the auxiliary inverter is a compressor inverter.
5. The power supply device for an electric vehicle according to claim 4 , wherein
a required voltage of the compressor inverter is determined in the control device on the basis of a set temperature of the vehicle air conditioner and vehicle interior temperature.
6. The power supply device for an electric vehicle according to claim 2 , wherein
the control device controls the DC-DC converter so that the direct current voltage stepped up in the DC-DC converter should be equal to or higher than the required voltage of the auxiliary inverter when the required voltage of the auxiliary inverter is equal to or higher than the direct current voltage of the power source as well as the required voltage of the auxiliary inverter is equal to or higher than the required voltage of the main inverter.