Title :
A new PWM method to reduce beat phenomenon in large-capacity inverters with low switching frequency
Author :
Iwaji, Yoshitaka ; Sukegawa, Takashi ; Okuyama, Toshiaki ; Ikimi, Takashi ; Shigyo, Masakane ; Tobise, Masahiro
Author_Institution :
Res. Lab., Hitachi Ltd., Ibaraki, Japan
Abstract :
In an asynchronous pulsewidth modulation (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., gate-turn-off thyristor inverters), when the fundamental frequency is high. Assuming that the beat phenomenon is caused by an error generated in the PWM process, the authors have introduced 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
Keywords :
DC-AC power convertors; PWM invertors; harmonic distortion; power conversion harmonics; thyristor convertors; PWM method; beat phenomenon reduction; carrier frequency; compensator; fundamental frequency; gate-turn-off thyristor inverters; large-capacity inverters; switching frequency; AC motors; Error correction; Industry Applications Society; Pulse inverters; Pulse width modulation; Pulse width modulation inverters; Space vector pulse width modulation; Switching frequency; Thyristors; Torque;
Journal_Title :
Industry Applications, IEEE Transactions on