TRV Rating Concepts and Generation of TRV Envelopes for Synthetic Testing of Extra 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 245 kV to 1200 kV power system with short circuit ratings up to 120kA. 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. Synthetic testing is an alternative equivalent method for testing of high voltage circuit breakers and is accepted by the standards. This paper presents a TRV rating concepts , IEC standards TRV envelopes and types of synthetic test circuits and their comparison. Analysis and mathematical modeling of 4-parameters TRV synthetic test circuit is done. A 4- parameters TRV synthetic test circuit based on parallel current injection method is designed and simulated for testing 420kV and 800 kV rating circuit-breakers as per new TRV requirements given in IEC 62271-100(2008).