Development and Fabrication of Automatic Controller and Triggering Circuit for Circuit Breakers Synthetic Test Circuit

Abstract

Short circuit tests on circuit breakers are performed to prove the ratings of the circuit breakers. 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. In order to test circuit breakers by synthetic testing, it is needed to accurately control the synthetic test circuit so as to satisfy the test criterion. In this paper the synthetic test circuit with automatic controller to interrupt short circuit current and to fire the triggered spark gap at the desired moment is presented. The control circuit has been setup and the experiment shows a good agreement with the predictions.