| 摘要 |
<p>PURPOSE:To greatly increase the effective tractive force with respect to acceleration, by providing a current pattern operating circuit performing control as a speed function and a current pattern limiter generating the same current patterns as the speed function of adhesive coefficient. CONSTITUTION:A current limiting value setter PT sets the acceleration current IREF of the electric car. The current pattern operating circuit CPL compares the acceleration setting current IREF and the main motor current IM and performs computation. The resultant error signal is given to the current pattern limiter. Said current pattern limiter CL imparts the pattern I of the main motor current as a function of the locomotive speed V. The current pattern I is a pattern which decreases with the increase of the speed V in inverse proportion. Furthermore, the output signal of the constant current limiting circuit ACR is given to phase shifters PS1 and PS2 of choppers CH1 and CH2, and the current conduction rate of the choppers are controlled so that the main motor current IM becomes the pattern currnt given by the limiter CL.</p> |
