MOA insulation condition and its operation properties on lightning protection of Qinghai-Tibet Railway

Ge´ermu to Lasa Segment of Qinghai-Tibet Railway is National Key Project under construction. As a highland railway with average elevation above 4500 meters, various factors related to high altitude (such as air pressure, dampness, temperature) influence the insulation condition of lightning protection device. MOA (metal oxide arrestor) as a lightning arrestor with predominant performance will be used on the lightning protection of power system along the line. Combined with the meteorological characteristic related to elevation in Qinghai-Tibet Plateau, the paper mainly analysis how the external insulation of MOA will be influenced; points out that reduce of external insulation discharge voltage and corona discharge voltage as well as other phenomena bring the breakdown and erosion of components, performance descending of air-proof and explosion protection system; based on the above analysis and operational experience of MOA on other high-elevation power supply systems, presents feasible measures to improve operational reliability of MOA on lightning protection of Qinghai-Tibet Railway.