Simulation of a Single-Phase Induction Motor with Dynamic Capacitor for Maximum Torque Operation

Many techniques are available for control of three-phase machines to extract the best performance. However, no generalized technique exists for the application to single-phase induction motor (SPIM) drives. An application of SPIM is not just limited to fans, but it is being used in many domestic gadgets and consumer electronics applications. In this paper, a SPIM is controlled using a dynamic capacitor for maximum torque operation. The SPIM system uses an indirect current control of a Voltage Source Inverter (VSI) with a capacitor on its DC bus to emulate a variable capacitor. This dynamic capacitor connected in series with an auxiliary winding, and is controlled in such a way to keep the main and auxiliary winding currents in phase quadrature to each other, resulting in production of maximum torque. A dynamic model of a SPIM is developed in stator reference frame (d-q) including the dynamic capacitor. The developed model is simulated in MATLAB to study the behavior of a SPIM. Performance of the SPIM drive is evaluated for proposed configuration through extensive simulations to demonstrate the effectiveness of the dynamic capacitor.