Results of experimental high current impulse 4/10s of metal oxide varistors zinc in the high voltage 220kv surge arrester

RESULTS OF EXPERIMENTAL HIGH CURRENT IMPULSE 4/10s OF METAL OXIDE VARISTORS ZINC IN THE HIGH VOLTAGE 220KV SURGE ARRESTER

PhD. Nguyen Huu Kien
National Key Laboratory for High Voltage Techniques – Institute of Energy
ABSTRACT
This paper presents the results of experimental researching the technical characteristics of metal oxides varistors zinc (V-ZnO) in the 220 kV surge arrester at the National Key Laboratory for High Voltage Techniques – Institute of Energy (HVLAB). The results of experimental researching the peak value of discharge current having a 4/10s impulse shape which is used to test the stability of the arrester on direct lightning strokes. The voltage-current linear characteristics of metal oxides varistor zinc V-ZnO at current on resistor plate of surge arrester. When voltage apply to the V-ZnO larger Upeak, a small increasement of voltage will make the current through the V-ZnO increase quickly. This feature is used to discharge the lightning when the over-voltage current appeare. Upeak is based reference limits to design the core of V-ZnO. From the results of this test allow to assess some category of the V-ZnO quality arrcording to IEC 60099-4, to install surge arrester into the grid with high efficiency.
Key words: Metal oxides varistor zinc; V-ZnO; V-SiC; Surge arrester.

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