Impedance frequency characteristics of MAGLEV power feed circuits

In Japan, the MAGLEV (magnetically levitated train) is now well along in development testing. The MAGLEV power source must supply a variable voltage and variable frequency source, and contains many higher harmonics which cause many problems such as inductive interference. Thus it is necessary to clarify the impedance frequency characteristics of the MAGLEV power feed circuit. In view of this situation, experiments and investigations concerning the impedance frequency characteristics of the coils for propulsion and the power feeding circuit at the Miyazaki Test Track have been performed but no theoretical analysis has been done. Thus a theoretical analysis was performed in this paper by applying the inverted L equivalent circuit to the coil for propulsion, from which the characteristics of the coils for propulsion were analyzed. In addition, the characteristics of the power feeding circuit could be clarified by assuming the equivalent circuit of the power feeder line. As a result, the measured values and calculated values were almost equal in both the characteristics of the coils for propulsion and those of the power feeding circuit.