Reactive Power Compensation With Nine-Switch AC/AC Converter and Predictive Current Control Applied to a Variable Speed Driving Induction Motor

The nine-switch AC/AC converter (NSC) is used as a substitute for the back-to-back converter (B2B). It is possible to use this converter for power factor (PF) correction during an AC motor driving due to its capability of current control on both three-phase terminals. This paper analyses the use of the Predictive Current Control (PCC) technique to operate a squirrel-cage induction motor (SCIM) connected to the grid through an NSC. Conditions of unity PF and reactive power compensation are evaluated for the grid-side while motor-side control is free to regulate the SCIM mechanical speed. Simulation results show that the NSC can operate with unity and leading power factor when using PCC in the existence of a mechanical torque in the SCIM's rotor shaft.