Distributed Capacitance Calculation Model in GIS Voltage Transformer’s Error Test

With the advantages of miniaturization and high reliability, Gas Insulated Substations (GIS) have been applied to power systems widely. However, GIS voltage transformers have troubles in boosting voltage in error test because of GIS’s special physical structure. A calculation model was proposed to solve the difficulty of distributed capacitances’ calculation when it adopts series resonance method in error test. By analyzing and getting the corresponding parameters of primary equipment, a GIS voltage transformer’s test connection equivalent model was built. Compared with measured value in a 500 kV GIS hydropower station, the error is below 8%. And the results confirmed that the long-distance bus and metal shell will form a large distributed capacitances which have a great impact on the error test. In this paper, the calculation model provides theoretical basis for error test. Moreover, it can be applied to field test, which will save equipment transportation costs, time and resources.