| 摘要 |
<P>PROBLEM TO BE SOLVED: To combine a reduction in a noise sound from a PWM-controlled power converter mounted to a vehicle and an improvement in the conversion efficiency. <P>SOLUTION: A power converter includes an inverter 2a driven by a PWM control, a noise level sensor 7 for detecting a noise within the vehicle, and a carrier frequency controlling section 8a for varying a carrier frequency for the PWM control opposite to the noise detected by the noise level sensor 7. When the noise within the vehicle due to a wind noise and a road noise is increased by high-speed running, the carrier frequency is decreased and the power conversion efficiency is enhanced. When the noise within the vehicle is decreased by low-speed running, the carrier frequency is increased and the noise is suppressed. <P>COPYRIGHT: (C)2007,JPO&INPIT |
