Development of PD Detection System for Propulsion Coils Arranged on Both Sidewalls of U-Shaped Guideways in Superconducting Maglev Systems Using Two On-Board Radio Interferometer Systems with Vector-Antennas

Continuous and simultaneous partial discharge (PD) detection for propulsion coils arranged on both sidewalls of the U-shaped guideways will be needed in the commercial operation of superconducting magnetic levitation (SC Maglev) systems to reduce the time and cost for condition monitoring. Two sets of an on-board radio interferometer system with a vector-antenna are proposed for the above solution. As comparing with our previous system, the sampling frequency, quantization bit rate, memory of acquisition of the new systems become higher frequency, higher resolution, and longer memory, respectively. The radio interferometer systems were used to detect PDs generated in an artificial cylinder-shaped void, which was inserted in the insulation layer of a mock-up of propulsion coil. The antennas of two radio interferometer systems were arranged to face each side, in consideration of the vehicle width of SC Maglev train. This paper describes relationships between the EM waves received by using the radio interferometer systems and the PD currents for the artificial cylinder-shaped voids.