A Novel Hybrid SVPWM Modulation Algorithm for Five Level Active Neutral-Point-Clamped Converter

Five level Active Neutral-Point-Clamped (5L-ANPC) converter is one of the promising multilevel converters attracting more and more attention. Among conventional modulation methods for 5L-ANPC converter, SVPWM is a competitive one to achieve high utilization of the DC voltage and small output waveform distortion. However, the calculation of the conventional five level SVPWM (5L-SVM) method is too complex. In order to solve this problem, a novel hybrid SVPWM modulation algorithm is proposed in this paper for 5L-ANPC converter. By using this modulation scheme, 5L-ANPC converter can be regarded as a cascaded multilevel converter (a two-level converter cascaded with a three-level floating-capacitor converter). Therefore, a non-calculation two-level SVPWM (2L-SVM) combined with a non-sinusoidal three-level SVPWM(3L-SVM) can be used to generate five level output voltage. Because of 2L-SVM without calculation, a low level SVM scheme (a non-sinusoidal 3L-SVM) can be directly applied to 5L-ANPC to reduce the control complexity compared with conventional 5L-SVM. Simulation and experiment results verify the effectiveness of the proposed modulation strategy.