AC 전동기 구동용 저역통과 LC필터를 가진 디지탈 인버터의 교류전원 파형 개선

The Current Waveform Inprovement of an AC Motor with Low Pass LC Filter Driven by a Digital Bridge Inverter

Recently, the AC motor which has a simple structure and needs less maintenance has become to be used frequently as a servomotor for position control in the automatic control field. This paper concerns with a method to improve the current waveveforms of the variable speed30 AC motor system driven by the single-pulse PWM, and the current waveforms are analyzed by FFT under various running conditions. The system is composed of a digital bridge inverter, low pass LC filter, and 3Φ AC motor. By the performance anaysis through the computer simulations and experiments , AC source of pseudo sine waveform can be obtained from the modulated alternating square voltage by means of the well designed LC filter.