A NEW APPROACH TO ESTIMTING POWER ANGLE OF SYNCHRONOUS GENERATORS

Power angle is one of the most important variables to represent the working condition of synchronous generators and the stability of power systems. This paper proposes a novel approach to estimating generator's power angle by employing sampling values of terminal voltages/ currents and some model parameters. It overcomes the drawbacks of traditional methods, which have inferior accuracy during system transients because of time-varying parameters and magnetic saturation. Theoretic formula and signal-processing procedures are detailed in the paper. And the algorithm is further implemented and integrated in the Phasor Measurement Unit we developed. A dynamic simulation is conducted to validate the proposed method and to compare its effect with the method based on non-electrical sensors. Results demonstrate that the developed approach can achieve very satisfied accuracy in both steady state and transient period of power systems. Since the novel method only depends on sampling of electrical quantities, it is easy for implementation and costs much less than methods involving non-electrical sensors.