A Protection Scheme for Long Lines with High-reactor Stations in a Wind Power Transmission System

Large-scale wind power is mainly delivered by long AC lines with additional high-reactor stations. Lack of research and solutions for the effects of reactive currents on line differential protection due to additional high-reactor stations. In order to solve the protection configuration problems, a typical case is selected to analyse the configured protection operation performance. Firstly, the impact of high-reactor stations access on line differential protection is investigated. Then the influence of different measurement point voltages on the capacitor current compensation calculation is also analyzed for the system after high-reactor stations access. Finally, a protection scheme is proposed for long lines with high-reactor stations in a large-scale wind farm transmission system. The proposed protection scheme has been verified by PSCAD / EMTDC to have a very good operational performance.