PERFORMANCE INVESTIGATION OF MATRIX CONVERTER FED INDUCTION MOTOR

Abstract

Power electronics is an emerging technology. New power circuits are invented and have to be included into the power electronics curriculum. One of the interesting new circuits is the matrix converter. The matrix converter is an array of controlled semiconductor switches that connects directly the three phase source to the three phase load without using any dc-link or large energy storing element, and therefore is called an all-silicon solution. This converter has several attractive features such as sinusoidal input and output currents, operation at unity power factor, regeneration capability. In the last few years, an increase in research work has been observed, bringing this topology closer to the industrial applications. Various modulation techniques are available for matrix converter. In this dissertation, Venturini modulation and space vector modulation techniques have been discussed extensively. Simulation results of these methods with R load and R-L load are shown. It is demonstrated that the output current is sinusoidal and the input displacement factor is unity. Comparative study of a matrix converter and a voltage source inverter is performed. An induction motor drive with field oriented control is taken up for the purpose. With simulation results, the advantages of a matrix converter over a voltage source inverter are shown. A hardware prototype of matrix converter is developed. The prototype is tested with R and R-L load using venturini modulation technique and space vector modulation. The prototype of the matrix converter is finally used for closed loop speed control of induction motor. Two control techniques have been implemented: simple v by f control and field oriented control. The steady state results of the drive are shown for both methods.