| 摘要 |
<P>PROBLEM TO BE SOLVED: To improve low-temperature starting characteristics of an engine while satisfying requirements such as miniaturization and cost reduction of a drive system in a vehicle having an engine and a motor generator as drive sources. <P>SOLUTION: A low voltage battery 20 being a power supply of electrical equipment of the vehicle has less reduction of power output at a low temperature, compared to a high voltage battery 18 being a power supply of the motor generator 12 for driving the vehicle. When an engine start request occurs, a motor control device switches the low voltage battery 20 to be connected between a neutral point 28 of the motor generator 12 and a DC input side of an inverter 22 and drives the motor generator 12 while stepping up the output voltage of the low voltage battery 20 by the inverter 22. In this way, by driving the motor generator 12 with the electric power of the low voltage battery 20 and cranking the engine, the low temperature starting characteristics of the engine is improved, and the drive system is miniaturized and cost-reduced by dispensing with a starter motor. <P>COPYRIGHT: (C)2011,JPO&INPIT |
