Generalized harmonic loss-factor as a novel important quality index of PWM techniques

Abstract

Different carrier-based and loss-optimized PWM methods of two- and three-level inverters are examined and compared from the viewpoint of the motor harmonic losses. For the presently used commutation frequencies these losses with a good accuracy are determined from the generalized loss-factors, which are expressed by analytical equations and usually independent of the commutation frequency of the inverter. The generalized loss-factors of bipolar, dipolar and unipolar PWM techniques with three and two phase commutations are compared in detail.