Testing of Reactor Switching for UHV Circuit Breakers

Reactor switching is a test duty for circuit breakers (CBs) in special locations. This duty is characterized by a relatively low current but the CB is stressed with high voltages. Furthermore, this is a stress which will appear frequently in breakers used for switching voltage-control elements. The different international standards define test procedures, which should be used to determine the CB characteristic and the withstand capability for the corresponding operating voltages. Usually, HV CBs need to be tested in synthetic test circuits. Due to the strong interaction between CBs and network synthetic test circuits, it is not possible to be used for inductive switching. Also, the direct test circuit may not be available due to the necessary short-circuit power and the required test voltages. Therefore, a test method has been developed to obtain the necessary information in a multistep method combining testing and calculation. Using the proposed method will enable smaller testing stations to give judgment on CB capabilities. For other very high requirements where even no test possibilities may exist, it will provide some evidence avoiding field tests. A validation of the presented multistep method is given in this paper.