| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To solve the problem in an air-conditioner housing a PWM inverter apparatus that when carrier frequency in motor drive is larger, switching loss of a power device such as IGBT in the motor drive is larger and energy saving is less, while when the carrier frequency is smaller, noises or vibrations are generated, so although selection of the carrier frequency that strikes a balance between energy saving and low noises is needed, there are cases where the noises of the carrier frequency may be noises. <P>SOLUTION: An air-conditioner is configured to detect environment under which the air-conditioner is uses, and the carrier frequency in motor drive is enhanced under a quiet environment where noises are not permitted and is lowered under a quiet environment where noises are permitted. <P>COPYRIGHT: (C)2011,JPO&INPIT</p> |
