Real-Time Calculation of Full-Cycle Asymmetrical SHEPWM Using Step Modulation Newton Algorithm

Restricted by the symmetrical characteristics of the output waveform and the solving method of the mathematical model, selective harmonic elimination pulsewidth modulation (SHEPWM) technology cannot output pulse waveforms with variable and complex time-frequency domain information in real-time, which limits its application in many automation fields. This article establishes a full-cycle (FC) asymmetrical SHEPWM mathematical model capable of outputting pulse waveform with arbitrary time-frequency domain information. Moreover, the step modulation Newton (SMN) algorithm is proposed to solve nonlinear transcendental equations. This method actualizes the real-time calculation of FC asymmetrical SHEPWM due to its advantages of low requirement in a precise initial value, high speed, as well as high accuracy in solving problems. The simulation and experimental results further verify the real-time, resiliency, and stability of the control system based on SMN.