Análise do conteúdo harmônico dos transformadores de potencial capacitivos (TPC) e a influência destes equipamentos em algoritmos de estimação fasorial.

Abstract

The coupling capacitor voltage transformer (CCVT), due to economic issues, it is applied in power electric systems (PES) with rated voltage above 138 kV. These devices are used, among other applications, for providing voltage data from the PES to protection distance relays. During the steady state, the CCVT is able to reproduce the voltage signal of the PES in theirs secondary windings. However, when a fault happens, the voltage at the output of this type of transformer is not a replica of the input signal. Therefore, the data provided from the CCVT to the relay drive this device to make a wrong estimation of the phasors which represents the system. At last, this could lead to error on the process of fault identification. This work, in a first moment, propose to investigate how a signal, distorted by high frequencies harmonic components due a fault, will be reproduced at the secondaries windings. After this analysis, it will be investigated how the transformers evaluated have influence on the algorithms used in order to estimate the fundamental phasors of the system.