New faulted phase selector solution for dealing with the effects of Type-4 Wind Turbine on present protection relaying algorithms

Abstract

Type 4 wind turbines are becoming one of the most employed technologies for all new wind turbines installed in the power system and their penetration is expected to increase. This technology presents the advantage that of fully decoupling the behavior of the generator from grid disturbances. This decoupling helps the wind turbine to reach the compliance requirements of international grid codes [1] during grid disturbances.Considering such circumstance, within Work Package 4 of EU funded MIGRATE Project, an ad-hoc Type 4 wind turbine model has been developed in Real-Time Digital Simulator (RTDS) platform, including algorithms for international grid code compliance and independent controls for positive and negative sequence current. The objective of developing such detailed RTDS model is to apply tests in laboratory to real protection relays, from different vendors, to study potential problems or limitations of present protection algorithms in the case of high penetration of this type of renewable energy generation sources into the grid. The in-depth analysis of the results obtained in such tests allows identifying specific weak points of the present protection algorithms in the considered scenarios, thus paving the way for the research on new protective solutions, as it is shown in the present paper.