| 摘要 |
<p>PURPOSE:To effectively obtain a chopper controller for an electric rolling stock safely by shortcircuiting a chopper under AND conditions of detecting the facts that the maximum conduction rate is detected and that a main motor voltage is large than a predetermined value. CONSTITUTION:A main motor voltage detector 15 detects a main motor voltage, i.e., a counterelectromotive force, and a main motor voltage detector circuit 16 outputs an Emo signal when a detection signal Em becomes higher than a set voltage value Emo. At this time, if a maximum conduction rate detector 13 detects the maximum conduction rate and outputs a maximum conduction rate detection signal gammamax, a chopper shortcircuiting circuit 14 operated under AND condition with the EMD signal to close a switch 8, thereby shortcircuiting a chopper 7. Thus, a full voltage can be applied to a main motor 5 after confirming that the counterelectromotive force of the motor 5 is sufficiently generated.</p> |
