Implementation of a V/ƒ motor speed controller using a matrix converter and fuzzy asymmetrical PWM

A novel V/f speed controller is proposed based on a fuzzy asymmetrical PWM modulation scheme and implemented with a low-cost microcontroller. The circuit is designed with a compact matrix converter with static free-wheeling path and achieves smooth regulation of the motor speed and high output power factor all over the dynamic range. The design is tested experimentally and is found to achieve superior speed regulation and power efficiency in comparison with other control methods.