论文信息 - A new PWM method to reduce beat phenomenon in large capacity inverters with low-switching frequency

A new PWM method to reduce beat phenomenon in large capacity inverters with low-switching frequency

In an asynchronous PWM method, the ratio of the carrier frequency to the fundamental frequency must be at least 15-20 in order to suppress the beat phenomenon. However, it is impossible to achieve this condition for large capacity inverters (e.g. GTO inverters), when the fundamental frequency is high. Assuming that the beat phenomenon is caused by an error generated in the PWM process, the authors introduce a compensator to reduce the error. As a result, beat phenomenon can be decreased for a low carrier frequency. Effectiveness of the proposed method is shown by experimental results.

[1] Bruno Velaerts,et al. A novel approach to the generation and optimization of three-level PWM wave forms for induction motor inverters , 1988, PESC '88 Record., 19th Annual IEEE Power Electronics Specialists Conference.

[2] Susumu Tadakuma,et al. Consideration on PWM Control for Neutral Point Clamped Inverter , 1992 .

[3] J. C. Salmon,et al. A three-phase PWM strategy using a stepped reference waveform (invertor drives) , 1991 .

[4] Hirofumi Akagi,et al. A New Neutral-Point-Clamped PWM Inverter , 1981, IEEE Transactions on Industry Applications.

[5] Yoshitaka Iwaji,et al. Introduction of the Harmonic Distortion Determining Factor and Its Application to Evaluating Real Time PWM Inverters , 1995, IEEE Transactions on Industry Applications.

[6] J.C. Salmon,et al. A 3-phase PWM strategy using a stepped reference waveform (for drive control) , 1989, Conference Record of the IEEE Industry Applications Society Annual Meeting,.