SVPWM Strategy With Minimum Common-Mode Voltage for Multilevel Converter Combining the Concept of the Nearest Level

Abstract

Multilevel converters are widely used in medium- and high-voltage high-power industrial applications. Space vector pulse width modulation (SVPWM) is one of the very promising modulation strategies for multilevel converters. However, the SVPWM strategy is difficult to implement as the number of levels increases. The output common-mode voltage (CMV) of the converter is another problem in the implementation of SVPWM strategy. In this paper, a new SVPWM strategy with minimum CMV for multilevel converter is proposed by combining the concept of the nearest level. The proposed SVPWM strategy only utilizes simple arithmetic operations and logical judgments, and completely avoids trigonometric functions and irrational number operations. Compared with the existing SVPWM methods, the proposed SVPWM strategy can quickly calculate the switching state with the minimum CMV in real-time by the concept of the nearest level, and avoids solving the non-homogeneous linear equations in the process of calculating the switching state corresponding to the space vector. It can be extended to any level converter without additional computational burden. Finally, the proposed SVPWM strategy is verified with extensive simulation and experimental studies.