Testing based evaluation of technical specification of metal oxide varistors zinc in the high voltage 110kv surge arrester

Nguyen Huu Kien, National Key Laboratory for High Voltage Techniques, Institute of Energy

Standard test with 8/20  s pulse for V-MOV-ZnO resitor block at HVLAB

This paper presents the results of experiment based evaluation method for technical characteristics of metal oxides varistors zinc (V-MOV-ZnO)which makes up 110 kV surge arrester. All tests were implemented at the National Key Laboratory for High Voltage Techniques – Institute of Energy (HVLAB). The 8/20s standard lightning impluse current tests were performed to test for the residual voltage; the voltage-current characteristics of metal oxides varistor zinc V-MOV-ZnO. Moreover, the voltage-current characteristics of V-MOV-ZnO was tested with 1mA current passed through resistor plate of V-MOV-ZnO. Once voltage applying to the V-MOV-ZnO is greater than Upeak, a small increasement of voltage will result in a very high current passing through the V-MOV-ZnO. This feature is used to discharge the lightning when very high transient over-voltage occurs. Upeak is reffered as a limit which must be taken into account when designing the V-MOV-ZnO arrester. All testing results practically allow to evaluate quality of the V-MOV-ZnO on some aspects arrcording to IEC 60099-4 and to ensure the effectiveness of surge arrester if utilized.
Key words: metal oxides varistor zinc; V-MOV-ZnO; surge arrester, test.
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