Development of Metal Oxide Varistors for Energy Absorption in DC Circuit Breakers within DC Distribution Networks

In this paper, a MOV(Metal Oxide Varistor), which is a component of a MOSA(Metal Oxide Surge Arrester) for DC circuit breakers required in MVDC(Medium Voltage Direct Current) distribution networks, is proposed. The developed MOV has a reference voltage of 7.2 kV @ 1 mA, a residual voltage of 17 kV @ 10 kA, and an absorbing energy of 39 kJ. Therefore, the proposed MOV has suitable characteristics for configuring a MOSA for DC circuit breakers in 42 kV MVDC distribution networks which requires an absorption energy of 2 MJ. In this paper, the design process and performance test results of the proposed MOV are presented.