Control of double capacitor single phase induction motor with a switched capacitore

Single phase induction motors that are a kind of AC machine, are used in a wide range. In most application, single phase induction motor is used with an auixiliary winding and a series connected starting capacitor. In industrial applications, the most common and used type of single phase induction motors are motors with two capacitors. One of these capacitors helps to constitute the starting torque, where the other one is used for steady-state the operating conditions to increase the efficiency. Recently, speed control of single phase induction motors are investigated because of the wide range applications of these motors. A capacitor controlled method can be used for speed control. Selecting suitable capacitor values is the most important problem of single phase induction motors. Switched capacitor method can be used for solving the problem of single phase induction motors. The value of the capacitor can be changed by an electronic switch which is in paralel connection to the capacitor. The capacitor is also connected in series with auixiliary winding. Any capacitor value can be obtained by controlling the on-off time of electronic switch. Finally, in this thesis, optimal capacity value is considered as a function of speed. Switched capacity single phase induction motor?s dynamical model is obtained by using MATLAB/Simulink. In this program, an induction motor with two capacitors is used and this capacitor is switched by an IGBT. Also, the switching times are obtained by help of an encoder that coupled the shaft of motor and a PIC microcontroller.