Abstract
Suppression of subsynchronous torsional interaction(SSTI) in electrical power system achieved with insertion of an inverter to transmission line in series. Active power of the transmission line is sensed and filtered by three sets of bandpass filters to get the torsional signal for feedback. The output signal of controller is converted to voltage reference signals for each phase by dq inverse transformation and the voltage reference signals are input to PWM control circuit to generate the gate firing signals for the inserted inverter. Simulation results show the control is effective to suppress the SSTI
