Position and Speed Estimation of Maglev Train Based on High-frequency Voltage Signal Injection Method

In this paper high-frequency voltage signal injection method was applied based on the machine-saliencies of linear synchronous motor used by maglev train. Three-phase symmetrical high-frequency voltage signals was added to the system before SVPWM regulator, which produced high-frequency current signals containing positive component and negative component. The negative current component included position and velocity signals of the mover of the maglev train. Position and velocity signals could be extracted from negative current component by rotating vector, filter and heterodyning-tracking observers. All process was discussed in detail in this paper. The simulation results verifies the correctness and availableness of this method.