A Novel Voltage Stability Sensitivity Index Incorporating the Slip of the Wind Generator and the Stochastic Wind Speed and Load

Abstract

This paper presents a novel voltage stability sensitivity index incorporating the slip of wind generator and stochastic wind speed and load. Tradition studies are insufficient to inquire the impact of the slip of asynchronous wind generators and stochastic wind speed and load on voltage stability index. Firstly, the slip of asynchronous generator is introduced as a new state variable, and thus new power balance equations including the slip as a state variable are formulated. Then, A novel power flow equation considering the balance between the average electromechanical power conversion and mechanical power of wind turbines that incorporate wind stochastic and intermittent uncertainty is proposed. Furthermore, the uncertainty load also be incorporated into the propose power flow equation. Finally, based on the Jacobian matrix for the novel probability power flow equation, novel sensitivity index that can be represent as the reactive power versus voltage incorporating the slip of wind generator and stochastic wind speed and load can be obtained.. The proposed methods are illustrated on the IEEE 68-bus system and the results show that the stochastic wind penetration and load can significantly affect voltage stability sensitivity index and critical bus also can be identified.