Application of Switching Devices in Power Networks

In the previous chapters, current interruption in switchgear with mechanically opening contacts has been considered, and important parameters of the current interruption process have been introduced. It has been explained that current waveform and amplitude as well as steepness and amplitude of the transient recovery voltage constitute the critical stresses to the switching arc and have a decisive impact on whether an interruption will succeed or fail. These stresses are very dependent on the network configuration where the switching device is employed. On the other hand, switching operations may expose other components in the network to higher stresses, such as overvoltages and overcurrents.