Testing procedure for metal oxide varistors protecting EHV series capacitors

Test procedures for metal oxide varistors used as overvoltage limiting protectors for EHV series capacitors are proposed. Basic varistor parameters are defined. The factors that must be taken into account and the test requirements are discussed. Special attention is devoted to the problem of power frequency current sharing among many parallel connected columns. The application of the procedures to the world's largest 500 kV series capacitor installation with metal oxide varistors as overvoltage protection is briefly described.<
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