抄録
Maglev vehicle HSST-05 had been operated in Yokohama Exhibition through the period by HSST Corp., which had taken the first licence of the railway service in Japan from Ministry of Transport. This paper describes the linear motor thrust control method, thrust characteristics, the new PWM method for HSST-05 and the successful results.
(1) HSST uses single sided linear induction motors (LIM) driven by the voltage source type PWM inverter mounted on the vehicle. The thrust force is controlled in accordance with inverter output voltage with constant slip frequency. The slip frequency is fixed at 12.5 Hz. Such larger slip frequency is effective to get better dynamic thrust performance in case of the variation of LIM air gap. The result of the running test showed the adequate performance to the designed scheme. However the end effect for higher speed range should be investigated in the near future.
(2) A new PWM method based on the instantaneous spatial vector theory has been applied for improving acoustic noise of the HSST. The zerovector control modulated by a constant carrier frequency are adopted and digitalized by DSP (TMS 32010). The cycling time is 20 ms and the carrier frequency is 400 Hz. This method is very effective to improve the feeling of PWM acoustic noise and to reduce the thrust force variation at various transient conditions.
