| 摘要 |
PURPOSE:To prevent the overcurrent of a motor from flowing by reducing a motor voltage in the secondary conductor defective section. CONSTITUTION:A slip frequency fs pattern, a motor current IM pattern, an inverter output voltage and a frequency ratio V/F pattern are outputted in response to a notch command 13. The output voltage of an inverter 11 is controlled by a control voltage VC in response to the V/F pattern, and the output frequency is controlled by fINV in response to the slip frequency fs pattern and the speed frequency fr. When a linear motor drive n vehicle enters the second conductor defective section, the ripple voltage of the IM rises, a VC reduction pattern unit 30 detects it and applies a VC reduction pattern to a VC limiter 24. Simultaneously, a distance counter 22 starts integration of the output pulse of a tachometer generator 21 and resets the VC reduction pattern when the integrated value arrives at a vehicle length. |
