Applicability study of single-phase reclosing in tie line of photovoltaic power plant

Abstract

Overhead transmission line faults are mostly single-phase grounding faults, and to ensure the power supply reliability of photovoltaic power plants in the cases of tie line transient faults, a feasible solution is to employ the single-phase reclosing. However, for the single-phase reclosing of the tie line, photovoltaic power source may face the over-voltage problem during the non-full phase operation, which will seriously affect the success rate of the single-phase reclosing. This paper, according to different non-full phase operation control strategies of photovoltaic power source, establishes the corresponding sequence network analysis models, and proposes the theoretical calculation method of non-full phase operation voltage, which takes account of different neutral point grounding modes of step-up transformer and different load levels. Meanwhile, the closing impulse problem of the single-phase reclosing is discussed. The correctness of the theoretical method is verified by digital simulation results. On this basis, the applicable scope and application suggestions of the single-phase reclosing are given. The research conclusions can provide important guidance and reference for the application of single-phase reclosing technology in tie line of renewable energy power plant.