Wind Farm Protection based on Directional Algorithm and Positive Sequence Current with and without Fiber Optic Backbone

Stand-alone Wind farm relay (WFR) of collector feeders in wind farm based on directional angle algorithm and positive sequence current is introduced in this paper. Many protection strategies use relay for each wind turbine generator (WTG), for large wind farm this is lead to extra cost. This paper introduces two scenarios, the first scenario for the step up transformer for smaller rated (≤ 1 MVA), where the transformer is protected by high rupture current fuse. The wind farm relay that protects collector feeders is backup protection for WTG fault zone. Stand-alone Wind farm relay reduces the overall cost of wind farm. For large transformers (>l MVA), the second scenario is proposed for large transformers (>1 MVA), the relay uses the digital signal from merging unit (MU) located on cable feeder and a WTG zone to detect internal faults in the collection feeder system and external faults in the transmission lines of the power grid, the digital signals of all merging units are transmitted to the WFR to detect faults on wind turbine generator or in the medium voltage (M.V) cable feeder, also the WFR send trip action for the faulted zone. The proposed protection algorithms performance is verified by carrying out various fault scenarios using MATLAB package. Several case studies have been carried out using a part of Zafarana wind farm which connected to 220 kV system of the unified Egyptian network. These case studies include different fault types and location.