Is overvoltage protection useful in MV distribution equipment?

Relevancy of overvoltage protection on MV networks is discussed according to the network structure and the switching equipment installed. Over-voltages can be generated by natural phenomena like lightning, by network faults like earth fault or by interaction of the switchgear with the network components. Simulation of a distribution network is presented to show the amplitude of the over-voltages and their rate of occurrence. Based on the results of the simulation guidelines for protection are proposed. Although the best place to install protection is closest to the protected equipment, protection is often installed on the switchboard. Installation examples are given for a new MV distribution switchboard design.