AN EXTENDED MAGNET IN A PASSIVE DL DT LIMITER

This article examines a composite magnetic device which has the potent ial to function as a rate of current change (dI/dt) limiter. A possibl e application of such a device is to protect voltage-source-fed system s, either ac or dc, from overcurrents during fault situations. The ope ration of this dI/dt limiter is discussed, and performance equations a re derived. Results obtained from this analysis are compared to a set of finite element simulations. An improvement to the basic design is s uggested, in which the permanent magnet slices are extended in order t o decrease the amount of leakage flux surrounding the dI/dt limiter.