Parametic Pump-Down of Synchronous Machine Oscillations

A new stabilizing technique for synchronous electric machines is presented. The method uses an external series controller (utilizing silicon-controlled rectifiers) which affects the synchronizing torque. Experimental studies on a 5-hp (horsepower) synchronous machine confirm the results of theoretical performance calculations. The primary advantage of the new method is in applications where more conventional stabilizing methods fail. A normally unstable doubly fed double-speed synchronous machine has been successfully stabilized by this technique.