Modeling MOV-protected series capacitors for short-circuit studies

A procedure for adequately modeling series capacitors protected by metal oxide varistor (MOV) in a conventional short-circuit program is proposed. It uses a quasi-linear model to represent the nonlinear characteristic of the MOVs, combined with a compensation technique to represent the intersequence coupling during unbalanced faults. The effectiveness of the method, which is valid for unbalanced as well as balanced faults, is demonstrated by comparing the results with those obtained using time-domain simulations. The results show that the proposed procedure can adequately and efficiently model MOV-protected series capacitors in a standard short-circuit program