Analysis of an AC-to-DC voltage source converter using PWM with phase and amplitude control

A comprehensive analysis of a pulse-width-modulated AC-to-DC voltage source converter under phase and amplitude control is presented. A general mathematical model of the converter, which is discontinuous, time-variant, and nonlinear, is first established. To obtain closed-form solutions, the following three techniques are used: Fourier analysis, transformation of reference frame, and small-signal linearization. Three models-a steady-state DC model, a low-frequency small-signal AC model, and a high-frequency model-are consequently developed. Three solution sets-the steady-state solution, various dynamic transfer functions, and the high-frequency harmonic components-are obtained from the three models. The theoretical results are verified experimentally