A New PWM Control based on an Optimized Zero Sequence Component injection: Application in a Two-Level Inverter

In this paper, a new optimization problem is proposed for improvement of PWM control of an inverter that supplies a generic RLE load. Two objectives functions are studied separately: Weighted Total Harmonic Distortion (WTHD) of load voltages and total losses. The gap contribution is related to optimize the zero sequence component waveform by defining special decision variables. By doing so, the proposed PWM strategy allows to improve the WTHD and efficiency of converters by keeping a classical PWM implementation scheme. Moreover this approach has the same way of thinking than the two main different classes of PWM strategies that are Space-Vector-based PWM (SVM) methods and classic carrier-based PWM methods (CBPWM). It is well known that there is an equivalence between SVM and CBPWM through the zero sequence component injection. So, optimized zero sequences are proposed for the two objectives functions considered, and the simulation results show a significant improvement compared to classical CBPWM strategies. Moreover the proposed strategy allows an implementation on existing hardware by modifying only the modulation component software.

Automated summary

A new optimization problem is proposed in this paper to improve the PWM control of an inverter for a generic RLE load by optimizing the zero sequence component waveform with special decision variables. The proposed PWM strategy is similar to both SVM and CBPWM methods, and simulation results show significant improvements compared to classical CBPWM strategies, with implementation possible on existing hardware.