Breaking capacity test of vacuum circuit breaker using synthetic test circuit with current zero forecast

In order to test the breaking capacity of vacuum circuit breakers, it is needed to accurately control the synthetic test circuit so as to satisfy the test criterion. For the asymmetry breaking current, it is difficulty to ignite accurately the sphere gaps ahead before zero in an appointed time so as to turn on the arc prolonging current circuit and high voltage circuit. As a result, once asleep the synthetic testing would be unsuccessful. In this paper the synthetic test circuit with current zero forecast is presented. Based on the discussion of the digital signal processing technology, the control circuit has been set up, and the experiment shows a good agreement with the predictions.