Sinusoidal waveform following method for optimum digital control of PWM inverter

It is necessary for control of a PWM inverter to consider the sinusoidal transient effect. This paper proposes a new control method which considers the effect using a compensator with the internal model principle especially for a sinusoidal reference waveform. It has a denominator z/sup 2/ - 2cos/spl omega/Tz + 1 of a transfer function which is equal to the z function of a sinusoidal waveform with an angular frequency u and a sample time T. The principle is also extended to a three-phase inverter with LC filters. Design examples of compensator and inverter feedback gains are determined by the deadbeat and the optimal control principles. They are investigated and validated for their fast performances theoretically.