Transient Stability Emergency Control Based on Real-time Power Angle Trajectory Fitting

Abstract

The emergence of wide area measurement system (WAMS) provides an opportunity for online transient stability assessment of power system. Based on the theory of complementary cluster energy barrier criterion (CCEBC), a transient stability control scheme based on real-time power angle trajectory fitting is proposed: The specific instability mode of the system is determined by the composite power angle, the system is transformed into a single machine infinite bus system; The real-time response information of WAMS is used to fit the power-angle trajectory of the disturbed system, and the instability judgment point of the extended phase trajectory is used as the end point of the measured fitting; Combined with extended equal area criterion (EEAC) theory, the tripping capacity of generation is calculated, and the controlled object is determined by the relative kinetic energy of each unit; In order to ensure the transient stability of the disturbed system, at the point of maximum acceleration power point and the point of instability judgment, the tripping control is performed respectively; Finally, a simulation example on Sanhua planning power grid verifies the effectiveness of the proposed emergency control strategy.