| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a technique for reducing or suppressing a carrier sound when windings connected to two inverters are closely arranged. <P>SOLUTION: The first and second three-phase inverters 10 and 20 the outputs of which are almost equal are connected to a first armature winding m1 and a second armature winding m2. The first armature winding m1 and the second armature winding m2 are closely arranged in a compressor 30, and they cooperate with each other when the compressor 30 is driven. A first carrier frequency of the first three-phase inverter 10 and a second carrier frequency of the second three-phase inverter 20 are mutually equal. A duty value of the first three-phase inverter 10 is almost equal to that of the second three-phase inverter 20. The first three-phase inverter 10 and the second three-phase inverter 20 operate in the same switching patterns. A phase difference (d) of the first carrier signal C1 and the second carrier signal C2 is in a range from 117.5 to 242.5 degrees. <P>COPYRIGHT: (C)2011,JPO&INPIT |
