| 摘要 |
<p>PURPOSE:To enable to automatically throttle a phase angle when a trolley wire voltage abruptly rises by inputting a trolley wire voltage signal into a digital control system. CONSTITUTION:A comparator 20 compares a current limiting value command Ip of an armature current with a feedback current value Ia' corresponding to the armature current Ia, applies a stage advance command in case of Ia'<Ip, and a stage reverse command in case of Ia'>=Ip to a reversible counter 22. A step converter 28 sets as a step 1 the output of the counter 22, and converts the step 1 into a step 2 in response to the amplitude of a trolley wire voltage Ep. A step/ phase converter 22 output a phase control signal to a main rectifier 11 in response to the step 2. Thus, the phase can be rapidly controlled in response to the abrupt change in the trolley wire voltage, thereby suppressing the deterioration in the rectification of a DC motor.</p> |
