Characteristics of Two-Phase Inverter-Fed Three-Phase Induction Motor Drive

In recent years, advances in power electronics have led to an increase of three-phase motor drive systems controlled by three-phase inverters. If inverters fail to operate, there is the possibility of a shutdown of the motor drives. In specific applications such as electric vehicles, inverter failure leads to a loss of the vehicle's propulsion ability, causing safety issues like traffic accidents and other consequences. In order to assure non-stop operation, emergency strategies for inverter failure are necessary. Less costly two-phase inverters are more frequently used as emergency support for conventional three-phase inverters. Recent research into motor drives utilizing two-phase inverters have developed advanced techniques with different control methods. This paper compares performances of the two-phase inverter-fed three-phase induction motor drive using V/f control and three indirect vector control methods are performed with the same experimental apparatus. The experiment evaluated the different control methods based on torque-speed characteristics and motor efficiency. Among the control methods evaluated, results identified flux weakening with the best torque-speed characteristics that also has the widest area in terms of motor efficiency.