Overvoltage protection study on vacuum breaker switched MV motors

This article presents the main results of a large overvoltage protection simulation study, carried out on vacuum breaker switched motors. Different protection solutions, as well as a great number of electrical network parameters, motor starting current and connecting cable characteristics were varied. The study showed that overvoltage protection installation is highly recommended for frequently started MV motors, switched by vacuum breakers regardless of the cable length, or even motor starting current. The main conclusions and results of this study are presented and commented on. The well known ATP-EMTP and MATLAB software were used for these analyses.