A Novel Random PWM Technique with a Constant Switching Frequency Utilizing an Offset Voltage
Do-Kyeom Kim, Sang-Hoon Kim · The Transactions of the Korean Institute of Power Electronics · 2017
This study proposes a novel random pulse-width modulation (PWM) technique with a constant switching frequency utilizing a random offset voltage. The proposed PWM technique spreads switching harmonics by varying the position of an active voltage vector without a switching frequency variation. The implementation of the proposed PWM technique is simple because it does not require additional hardware and complex algorithm. The proposed random PWM technique is compared with the conventional PWM technique on the factors of harmonic spectrum, total harmonic distortion, and harmonic spread factor to confirm the harmonic spread effect. The validity of the proposed method is verified by simulations and experiments on a three-phase inverter drive system.