An Electronic Switch for the Transient Testing of AC Networks and Machines

The paper describes an electronic switching device for the transient testing of small ac machines and network models. It is suitable for single-phase or three-phase operation. Precisely timed switching transients can be produced in any or all phases of the tested system. Switching operations in the individual phases can be performed simultaneously or with independent timing. The accuracy of timing is ± 0.5 electrical degree with a timing range from 0 to 2777 cycles. Thyristors are used as the main switching elements. They can continually carry 265 A r.m.s.; the peak inverse voltage across the switching elements is 600V. Several tests, which have been carried out with the device so far, are described and typical test results are given.