Research on Single-Ended Protection for Wind Power Full-DC Transmission System Based on Generalized S Transform

Wind power Full-DC transmission system can effectively solve the problems of harmonic and reactive power compensation that exist in wind power AC collection and transmission, and has broad development prospects. It contains a large number of power electronic converters. These power electronic converters have a limited ability to withstand overcurrent. Therefore, researching fast and accurate fault identification line protection is an urgent need for the development of DC power grids. This article analyzes the attenuation characteristics of the initial traveling wave frequency component at the installation site of internal and external fault. Since the difference in attenuation of the initial traveling wave frequency component of internal and external faults. The paper proposes a single terminal protection based on the high and low-frequency ratio of initial voltage backward traveling wave. Finally, a four-terminal wind power full-DC transmission system model is established and verified using PSCAD/EMTDC. Theoretical analysis and simulation results show that the proposed protection scheme can correctly internal and external faults, accurately select fault poles, setting is simple and easy to operate, with strong resistance to fault resistance.