Degradation Assessment of Power Semiconductors Applied in Static VAr Compensator

This paper presents a methodology for degradation assessment of power semiconductors, applied in static VAr compensators (SVC) of the types thyristor switched capacitor (TSC) and thyristor controlled reactor (TCR), that it aims at the improvement of the operational performance of these equipment. The methodology allows the identification of defective semiconductors, and the preventive substitution of these components, in order to prevent that the same ones come to fail in service, causing operational perturbations to the electrical system. The methodology defines the parameters of the semiconductors that can be used for the evaluation of the degradation. The conclusions are based on tests carried on semiconductors, with different states of degradation, from static compensators installed in the system of transmission of CHESF-Companhia Hidro Eletrica do Sao Francisco