MULTILEVEL PULSEWIDTH MODULATION SINUSOIDAL INVERTER WITH MODULATION SWITCHING AND CARRIER FREQUENCY-MODULATION

This paper discusses the basic characteristics of the multilevel PWM s inusoidal inverter based on the modulation switching. The considered P WM is to repeat the modulation operation of the leading and the traili ng edges at each peak of the input reference sinusoidal signal. The fe ature of the method is that the undesirable harmonic components distri buted around the carrier angular frequency beta are decreased greatly. It is made possible as a result to realize an N-level PWM sinusoidal inverter with the distortion rate of 0.3 percent or less and the maxim um operating angular frequency of N beta/6. Then, by combining the car rier frequency modulation, a high-frequency sinusoidal inverter that o perates at 2 beta/pi [Hz] is developed.