Transient Voltage Stability Analysis of Hybrid Sending Systems with Large Scale of Wind Power

Abstract

Ultra High Voltage Direct Current (UHVDC) transmission can improve the consumptive ability of wind power for the sending grid, but the voltage characteristics of hybrid grid lead to voltage fluctuation and reduce the transient voltage stability of the ystem. This paper established a hybrid sending grid model with large scale of wind power in DIgSILENT/PowerFactory, and put forward two quantitative indexes, called severity of voltage fluctuations and transient instability risk. Based on the indexes, this paper qualitatively analyzes the influence of output proportion of different type wind turbines, and the wind power penetration on the sending system transient voltage stability, quantizes the risk of transient instability. The study shows that the indexes can effectively measure the transient voltage stability of the system. Increasing the output proportion of Doubly-Fed Induction Generator (DFIG) can reduce the risk of transient instability. The transient voltage stability decreases with the increase of the wind power penetration.