Transient Stability Analysis of Wind Generator System with the Consideration of Multi-Mass Shaft Model

In order to investigate the impacts of the integration of wind farms into utilities networks, it is necessary to analyze the transient characteristic of wind power generation system (WPGS). In most of the cases, it is seen that the simple one-mass lumped model is considered for transient stability analysis of wind generator. But for the sake of exact analysis of transient stability of WPGS, it is needed to consider multi-mass shaft system model. In this study a detailed analysis has been done with the consideration of two-mass shaft system model of wind generator system when a severe network disturbance occurs in power system. Moreover, an online logical pitch controller has been proposed, which can enhance the transient performance of WPGS as well as maintain output power of wind generator at rated level when wind speed is above the rated speed.