Multi-Condition Simulation Analysis of Power Quality for Cascade Quasi-Z-Source AC-AC Voltage Regulator

Abstract

To solve high harmonic distortion of traditional AC voltage regulators, this paper establishes a simulation model of cascade quasi-Z-source AC regulator in MATLAB/Simulink. Steady-state waveforms under various duty cycles, dynamic responses to sudden duty cycle and load changes, as well as FFT and THD with or without filter capacitor are analyzed. Simulation results demonstrate that the system has the lowest THD when duty cycle is $\mathbf{0 . 4} \sim \mathbf{0 . 7}$, and the filter can significantly suppress harmonics. This paper only focuses on simulation analysis, while theoretical derivation and prototype tests have been reported in previous journals. The conclusions support parameter optimization of the regulator.