Analysis and Computer Aided Design of Synthetic Testing Circuits for High Voltage Circuit Breakers

Abstract

Development in electrical power transmission system requires the use of circuit breakers with increasing breaking capacity. At present circuit breakers are to be installed on 245kV to 760 kV power system with short circuit ratings upto 63kA. To test high voltage CBs, direct testing using the power system or short circuit alternators are not feasible. The testing of high voltage CBs of larger capacity requires very large capacity of testing station. To increase testing plant power is neither an economical nor a very practical solution. Therefore indirect methods of testing are used for testing of large CBs. Synthetic testing is an alternative equivalent method for testing of high voltage circuit breakers and is accepted by the standards. Parallel current injection synthetic testing is the most widely used method for testing of CBs. This paper discusses transient recovery voltage(TRV) rating concepts and analysis of synthetic testing circuits according to IEC. Design and simulation of 4-parameters TRV synthetic testing circuits is done by using PSIM simulator. Design considerations of the parallel current injection synthetic testing circuit ( Weil – Dobke) circuit is focussed and two 4-parameters TRV circuits are simulated. Simulation results are shown for a 245kV and 420 kV circuit breaker.