Improving performance of slip-recovery drive: An approach using fuzzy techniques

Conventional slip-recovery drives are plagued with a low overall power factor, due to the naturally commutated power convertor in the rotor circuit. One solution consists of adding two GTOs to the converter bridge, in order to transform it into a fully controllable inverter, which allows for independent control over voltage and displacement factor. When appropriately controlled, this converter is capable of producing reactive power in just the right amount to fully compensate the reactive power consumed by the power induction machine. Unity power displacement factor is then attainable over most of the operating range. A controller based on a fuzzy logic expert system is proposed.<>