Optimized Pulse Patterns Applied to Three-Level Inverter Based on Extended Newton-Raphson-based Optimizer Algorithm

This paper introduces the synchronous optimized pulse patterns (OPPs) modulation for NPC three-level inverter operating at low switching frequency, which minimizes the harmonic distortions of inductive loads. In order to address the issues of the traditional method where numerical algorithms require initial values and the premature convergence of the Newton-Raphson optimization algorithm (NRBO), this paper proposes an extended Newton-Raphson optimization algorithm (ENRBO) to solve the switching angles of the OPPs problem. By incorporating Lévy flight along with the expanded and narrowed exploration actions of the Aquila Optimizer(AO), the ENRBO has better optimization accuracy and can jump out of local optimum. The simulation model is built by MATLAB software, and the simulation results of the switching angles at the switching frequency of 250 Hz are verified. The experiments show that the ENRBO algorithm has a stronger advantage in solving accuracy than the NRBO algorithm, and the current total harmonic distortion rate(THD) is $\mathbf{1. 9 6 \%}$.