A study of transient induced voltages on a Maglev train coil system

The paper discusses transient induced voltages to the superconducting coil system of a magnetic levitation (Maglev) train planned in Japan from an overhead ground wire (GW) which protects the coil system from lightning strokes. A simplified lumped-circuit coil model is developed based on the two-port theory of an L equivalent circuit of a distributed-parameter line. Its impedances are evaluated from the impedance and admittance matrices of an overhead multiconductor system, which represents the coil, using the EMTP CABLE CONSTANTS. Calculated results of transient induced voltages by the proposed coil model agree satisfactorily with experimental results. It is made clear that the greater the grounding resistance and the smaller the separation between the coil and the GW and the span length of grounding, the greater the induced voltage.<
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