Voltage support strategy of SNOP under fault circumstance

Abstract

Soft normally open point (SNOP) is a power electronic device installed at normally open point (NOP) in a distribution network which can greatly promote the flexibility and controllability of distribution network. This paper introduces the typical installation of SNOP, and take the three-terminal SNOP converter station demonstration project in Hangzhou as case study. This paper is divided into two parts. Firstly, a new strategy which uses power of feeders' load to balance power flow among feeders is proposed. Then under fault circumstances, voltage support strategy of injecting positive active and reactive current based on line resistance-reactance ratio (R/X) is proposed. Simulation results verify the accuracy and effectiveness of the strategies adopted.