This paper describes harmonic evaluation of three phase carrier-based two-level and three-level PWM methods. The harmonic distortion determining factor, which represents the intrinsic spectral property of individual PWM methods, is used as the common basis. Almost all the carrier-based PWM schemes that have been proposed so far are considered. It is concluded that in AC drives the third harmonic injected sine PWM scheme is suitable for two-level inverters, and the double carrier unipolar PWM scheme is suitable for three-level inverters.
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