A HYBRID INVERTER CYCLOCONVERTER-BASED VARIABLE-SPEED 3-PHASE INDUCTION-MOTOR DRIVE FOR SINGLE-PHASE INPUTS

This paper presents a simple converter topology for driving a three-ph ase induction motor with a single-phase ac supply, Using only two acti ve switches and a Triac, the converter can start the motor with high s tarting torque and low input current, and can bring the motor up to fu ll speed using a very cost-effective, single-phase field-oriented cont rol strategy, The converter supplies balanced output voltages at rated frequency with virtually no output distortion and with very high inpu t power factor, In this paper, the capability contours for different s peed ranges and various operating modes are addressed; the trade-offs between output torque, torque ripple, input current distortion, and in verter rating are also explained, and the proposed control approaches are supported by simulation and test results.