Voltage regulation of a stand-alone induction generator using thyristor-switched capacitors

Induction generators operating in a stand-alone mode are increasingly being used in isolated areas. Such a generator has very poor voltage regulation. This paper proposes a simple thyristor-switched capacitor (TSC) type voltage regulator for a stand-alone induction generator to maintain voltage within the upper and lower acceptable limits. The capacitor size in each TSC branch is selected very carefully to minimize the number of branches needed to reduce the cost of the controller. This requires evaluating the generator characteristics for constant voltage operations. A set of equations is also drive and solved using a numerical based routine to get such characteristics. The proposed method of voltage regulation is then tested on a 1.5-kW induction generator. The simulation results obtained by the proposed method are also compared with the corresponding actual values found through an experimental setup and are observed to be in very good agreement.