Design and evaluation of PWM control circuits for DC/AC converters using PSPICE

The authors propose a way to design and evaluate the control circuit stage for a three-phase DC/AC power converter. PSPICE offers the possibility of design and evaluation of the complete system which includes control circuit, DC/AC power converter and the motor. This is very important because it is possible to see how the control circuit determines the performance of the whole system. This proposal includes all parts of the system, but with special emphasis on the control circuit. In the control circuit, it is possible to evaluate several PWM techniques. The software employed allows the evaluation of total harmonic distortion, THD, produced by each technique, it also allows evaluation of bipolar power waveshapes, and provides a good reference for the hardware required for control circuit implementation. An example is showed in which the isolation stage required between control circuit and power stage are included. Computational and practical results are also presented