Terminal voltage correlation-based adaptive reclosure strategy for VSC-MTDC grids

Auto-reclosure in VSC-MTDC grids has the defect of blindly reclosing. Research on adaptive reclosure strategies capable of identifying fault property and arc extinction time is essential to promote the reliability of power supply. This paper proposes a novel adaptive reclosure strategy for VSC-MTDC grids. At first, the terminal voltage is derivated by Marti model, which takes the distributed and frequency-dependent characteristics of the line parameters into account. The calculation result of the terminal voltage achieves high accuracy. Subsequently, a main criterion exploiting Pearson correlation coefficient between the calculated terminal voltage and the actual terminal voltage on the faulty line is proposed for identifying the fault property and the arc extinction time. Moreover, an auxiliary criterion utilizing the steady-state amplitude of the terminal voltage is added to further ensure the identification reliability of fault property. Finally, the effectiveness of the adaptive reclosure strategy is verified in PSCAD/EMTDC. The influencing factors and advantages of the proposed strategy are discussed and compared.