Off-line optimized pulse patterns for minimum distortion using the method of simulated annealing with the downhill simplex

Abstract

In high power drives the switching frequency is limited by switching losses. In order to obtain minimum distortion at low switching frequency off-line optimized pulse patterns are used. The method of steepest gradient, used in the past, does not necessarily provide the best method. It has a tendency to be locked in the local minima. The method of simulated annealing applied along with the downhill simplex has the ability to modify the structure of the problem. In so doing it is able to avoid the local minima and reach a global minimum. This provides a simple effective means of pulse pattern optimization. Optimized pulse patterns are generated and the performance of this method is discussed.