| 摘要 |
PROBLEM TO BE SOLVED: To prevent generation of power over in an inverter drive type motor for driving a compressor body in response to a change of the suction side pressure of the compressor body. SOLUTION: A relationship between the discharge side pressure Pd of the compressor body 10 and a target frequency F pid for achieving the rotating speed of the motor 15, which makes the discharge side pressure Pd coincides with a target pressure Pf, is previously provided, and the target frequency F pid is computed based on the detected discharge side pressure Pd. A relationship between the suction side pressure Ps of the compressor body 10 and the upper limit frequency F max for achieving the rotating speed for operating the motor 15 at a rated output or less under the suction side pressure Ps is previously provided, and the upper limit frequency F max is computed based on the detected suction side pressure Ps, and is compared with the target frequency F pid. The motor 15 is driven at a lower frequency of them. COPYRIGHT: (C)2011,JPO&INPIT
|
