| 摘要 |
PURPOSE:To realize continuous operation of service machines without exerting excessive load on a normal power supply circuit by determining the operating frequency of an inverter with a pattern predetermined according to a detected value of temperature and controlling the frequency of the service machine with thus determined operating frequency. CONSTITUTION:Upon fault of an inverter 5a in a power supply circuit of vehicle A, inverters 8a, 8b are fed with DC power only from vehicle B thus sustaining operation of compressors 9a, 9b. Since the power supply circuit of vehicle B is exerted with excessive load, temperature of main transformer 6b increases. The temperature rise is detected by a temperature sensor 12b and fed through a comparator 14 to a pattern generator. The pattern generator 15 determines an operating frequency pattern predetermined for the temperature sensor value and provides an operating frequency command to the inverters 8a, 8b. The inverters 8a, 8b control the rotational speeds of the compressors 9a, 9b based on the operating frequency commands. |
