Control apparatus of AC motor and refrigerating and air conditioning apparatus using same

• Main Authors: NOTOHARA YASUO, HIZUME TATSUYA, SUMITA SATOSHI
• Format: Patent
• Language: Chinese; English
• Published: 19.12.2012
• Subjects: BLASTING; COLD ROOMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORSOR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER; COOLING OR FREEZING APPARATUS NOT COVERED BY ANY OTHERSUBCLASS; ELECTRICITY; GENERATION; HEAT PUMP SYSTEMS; HEATING; ICE-BOXES; LIGHTING; LIQUEFACTION SOLIDIFICATION OF GASES; MANUFACTURE OR STORAGE OF ICE; MECHANICAL ENGINEERING; REFRIGERATION OR COOLING; REFRIGERATORS; WEAPONS

The invention provides a control apparatus of an AC motor and a refrigerating and air conditioning apparatus using the same. According the invention, a DC bus current can be correctly detected and the AC motor can be driven in high performance, even in the case of a low modulation rate such as using the AC motor in a low-load or low-speed region. The control apparatus of the AC motor comprises a DC power supply; an inverter which converts a direct current provided by the DC power supply into an alternating current; a control circuit of the inverter for controlling the switching elements of the inverter; a DC-bus current detector for detecting a DC bus current flowing in the inverter; a low pass filter for smoothing the DC bus current detected by the DC-bus current detector; and a corrector for correcting attenuation amount of the DC bus current smoothed by the low pass filter.