Dynamic braking resistor for control of subsynchronous resonant modes

A dynamic braking resistor control strategy has been proposed to damp the slowly growing subsynchronous resonant frequency oscillations. It employs generator speed variation, rotor angle and power variation signals to switch in braking resistors at the generator terminal. The proposed control has been tested on the IEEE second benchmark model for subsynchronous resonance studies. The dynamically switched braking resistors have been found to control the unstable modes very effectively. The control algorithm is simple and its realization will require very little hardware.