Adjustable-speed single-phase IM drive with reduced number of switches

A novel low-cost single-phase induction machine drive containing only two controlled solid-state switches is presented. The drive is intended for heating, ventilation, and air conditioning or a similar type of application requiring variable-speed operation with a fan-type load characteristic. An experimental drive based on the proposed setup has been built to verify its practical viability and to analyze its properties. The paper presents the results obtained from an investigation into this new topology and discusses the properties and characteristics of the drive for the entire speed range from 0 to 60 Hz.