Applicability Analysis of Distance Protection for the Line Integrated with High Proportional Wind Farm

The performance of conventional protections is serious challenged by different fault characteristics of wind turbine, compared to the synchronous generators. The existing studies can only illustrate the applicability of protections to the renewable energy transmission system through qualitative analysis or extensive simulations. This paper proposes a quantitative evaluation method for distance protection applicability in wind power transmission system. Firstly, by deriving the fault current of doubly-fed induction generators, the Fourier algorithm error of the fundamental frequency current under the influence of frequency deviation phenomenon is calculated. Secondly, based on the analysis of the measured impedance error caused by the Fourier algorithm error, the action accuracy of the distance protection under different operation states and fault conditions are obtained. In particular, the protection applicability under different wind power ratios is evaluated for the wind power transmission system bundled with synchronous generators. Finally, a real time simulation model of wind power transmission system is built based on RTDS platform, and extensive simulation cases are carried out to verify the validity of the proposed method.