| 摘要 |
PURPOSE:To supply power with a frequency lower than a power supply frequency and suppress high pitched tones created by rotary machines by a method wherein an outdoor blower is connected to a motor-generator through a frequency converter which reduces the power supply frequency of the motor- generator. CONSTITUTION:A frequency converter 15 is provided between a motor-generator 16 and compressor and blower 8 and 13. The power supply frequency of 400Hz outputted from the motor-generator 16 is converted into the frequency of 60Hz and supplied to the compressor 8 and the blower 13. That is, the compressor 8 and the blower 13, i.e., rotary machines, are driven by a power with the frequency which is reduced to 60Hz by the frequency converter 15. Therefore, the rotary machines rotate with low speeds and the machines do not create high pitch tones, so that harsh noises can be avoided. |
