Wind Plant Interaction in a 345-kV Series-compensated Power System—Electromagnetic Transient Program Modeling and Event Analysis

Abstract

Application of series capacitors on high voltage transmission lines has recently been gaining attention due to sub-synchronous interaction concerns with wind turbines based on doubly fed induction generators. However, most reported analysis is based on single-machine representation of the wind plant. While this approach is convenient for eigenvalue analysis and frequency scanning studies, the effect of ignoring the collection system and multiple wind turbines will result in current oscillations that may not capture all interacting frequencies. This article presents the investigation of a wind plant interaction event observed in a practical 345-kV series-compensated power system along with the development of a full-scale Electromagnetic Transient Program model. Multiple interaction frequencies in three distinct frequency ranges with low damping was identified in both Electromagnetic Transient Program simulations and event records. This demonstrates the need for full-scale Electromagnetic Transient Program models when designing sub-synchronous protection schemes and testing of sub-synchronous interaction damping controllers. Discrete Fourier transform and Prony analysis have been used for analysis of frequency and damping content in the resulting current oscillations. The Alternative Transients Program version of the Electromagnetic Transient Program was used to perform the time-domain simulations.