Bad Data Identification for Voltage Sag State Estimation in Distribution System with Wind Farm Connections

The problem of the low voltage ride through in distribution system with wind farm connections is actually the voltage sags propagation problems. Valid voltage Sag State Estimation (SSE) can check the possible severity of the voltage faced by the wind generators. Since SSE algorithm is a 2nd curve fitting algorithm, the estimation accuracy is mostly influenced by the validity of the metered data, especially the wrong data at the key points would cause the failure of all state estimation. In response to this question, the bad data identification algorithm in SSE is introduced, and the mathematic model of bad data revisement is also proposed in this paper. The simulation results proved the good performance of the algorithm in paper. And the work in paper will help to enhance the LVRT capacity in distribution substation by improving the relay' performance.