Analytical Modelling of Periodical PWM Converter Fed R-L Load

摘要

A new method for time-domain analysis of power converters with periodic pulse width modulation (PWM) is developed. The method is based on mixed p-z description of linear periodically time-varying system. The model is a applicable for converters with an explicitly determined output voltage (converters with forced commutation). The mathematical model uses the Laplace and modified Z transforms. The solution is not dependent on the number of the pulses of the PWM pattern Instead of solution of algebraic equations the change of switching instants is reflected in the solution only by a change in two values, namely m{sub}k and n{sub}k. The derived equations are validated using a 3 kW three-phase inverter.