Impact on the power system of single-phase input cycloconvertor motor drives

The paper presents the external line side performance of new single-phase input cycloconvertor motor drives for household and similar applications. Both single-phase to two-phase and single-phase to three-phase versions of cycloconvertors, which operate using a double integral control technique, are considered. With this technique, the motor flux linkages follow sinusoidal references. For the motors studied, the input current harmonics of the cycloconvertors are lower than the limitations in IEC Standard IEC 555-2 over a wide load and frequency range. A standard industrial star connected three-phase induction motor, reconnected in delta, was used with the single-phase to three-phase cycloconvertor, but a redesigned motor could further improve the input power factor and efficiency. The single-phase to three-phase cycloconvertor motor drive has lower cost and better performance than the single-phase to two-phase drive. Both experimental and simulated results are presented in the paper, and the simulations agree with the measurements