2006 Volume 126 Issue 11 Pages 1304-1310
Fast responses without any steady-state errors are required for control of a sinusoidal PWM inverter. There are two key points. One is that its reference voltage waveform is not constant but sinusoidal. It is necessary to design a compensator by considering these sinusoidal variations of the reference waveform to get a good steady-state and fast transient response. A sinusoidal tracking compensator which is based on the optimal control and the internal model principle has been proposed by the authors to realize a response with no deviation for a periodic sinusoidal reference input. The other is that compensator and feedback (FB) gains have a trade-off between responses and sensitivities to noises and they can not be too large. Feedforward(FF) compensation can improve responses without alternating system stabilities. This paper proposes a PWM control system which has a sinusoidal FB and an inverse system FF compensators. According to the inverse system FF compensation, appropriate nominal control input values are determined to give the reference steady-state response. Therefore the input values are computed by deconvolving a set of system response equations inversely. The proposed system is investigated and validated through theoretical and experimental results for a rated, an unbalanced, and a rectifier loads by using a simulator Matlab and a DSP system at the switching frequency of 20kHz. The proposed control showed better performances than the original FB and the preview controls.
The transactions of the Institute of Electrical Engineers of Japan.C
The Journal of the Institute of Electrical Engineers of Japan