PERFORMANCE INVESTIGATION OF PC BASED PWM INVERTER FED INDUCTION MOTOR DRIVE

Abstract

Regular sampling techniques posses well defined. modulation processes which give rise to the possibility of developing real-time algorithms, capable of generating PWM control in the frequency range of inverter, with minimal storage requirements. This is an over-riding advantage compared to optimal strategies, particularly in low frequency range where memory limitations inhibit the switching frequencies with optimal waveforms. For real-time implementation of PWM waveforms using microcomputer, there are different techniques of realization depending upon the type of modulation process. The basic hardware and software gets modified depending upon the technique of realization and the type of PWM waveform. Hence the above technique though useful lacks generality. A general method of generation of different types of PWM waveforms would be highly desirable in studying their relative merits and demerits. The present work concerns with the development of a method for real-time implementation of following three different kinds of two level regular sampled PWM techniques for induction motor drive. (i) Optimal Regular Sampled PWM (ii) Asymmetric Regular Sampled PWM (iii) Symmetric Regular Sampled PWM