Comprehensive Analysis of Transient Overvoltage Phenomena for Metal-Oxide Varistor Surge Arrester in LCC-HVDC Transmission System with Special Protection Scheme

Abstract

This paper proposes a systematic and deterministic method for metal-oxide varistor (MOV) surge arrester selection based on the comprehensive analysis in line-commutated converter (LCC)-based high-voltage direct current (HVDC) transmission systems. For the MOV surge arrester, this paper investigates several significant impacts on the transient overvoltage (TOV) phenomena, which is affected by practical factors such as an operating point of the LCC-HVDC system, synchronous machine operating status of the power system, AC passive filter trip, and communication delay in a special protection system (SPS). In order to determine an appropriate rating of surge arrester, especially for TOV, this paper considers a pattern, magnitude, and duration of TOV based on various fault scenarios in an electrical power system with an LCC-HVDC system. A screening study method with 60 Hz and RMS-based balance system is conducted for examining a wide range of fault scenarios, and then for the specific test cases that need a detailed analysis, electro-magnetic transient (EMT)-based analysis models are developed with an approvable boundary setting method through the equivalent network translation tool. A detailed EMT study is subsequent based on the distinguished cases; as a result, the exact number of metal-oxide resistor stacks could be obtained through the detailed TOV study according to this procedure. The efficacy of the selection method from the proposed procedure based on the comprehensive analysis are verified on a specific power system with a 1.5 GW DC ± 500 kV symmetric monopole LCC-HVDC transmission system.