Monitoring power system small-signal rotor angle stability under ambient operating conditions
An electrical power system is designed to provide safe and reliable supply to customers. However well designed the system, disturbances are unavoidable during the operation and the system should be able to continue secure operation. In fact, if it can be early determined that the system is moving towards an unsecure region, the operators can take necessary safety actions to keep the system secure. Thus, the main goal of this study is to develop novel techniques to monitor the stability of an electrical power system in real time. A power system can be in an unsecure condition due to different forms of instabilities. The main focus of this study is the instability of the generator rotor angles subsequent to small magnitude disturbances where the instability is due to the poor decaying rate (damping) of generator rotor angle oscillations. This study develops novel algorithms to real time monitor the damping of such oscillations where the value provides an indication on whether the system is stable or not as well as if it is stable then how much it is close to instability.