| 摘要 |
<p>PURPOSE:To reduce the variation in the current of a motor by controlling the phase of an initial current transformer from above the prescribed current flowing angle in accordance with a constant current command value at the switching time when starting conducting of a following rectifier after the current transformer initially controlled in phase becomes full output state. CONSTITUTION:A high voltage is supplied through a pantograph to the transformer of an AC electric motor coach to energize the primary coil of the transformer. The secondary coil of the transformer is divided into four coil segments, which are respectively connected to rectifiers 3-1-3-4. The rectifiers 3-1-3-4 are connected in cascade to drive a motor. A logic circuit 10 inputs a notch signal N, a current command value Ip and further detected motor current I. The circuit 10 stores a firing angle corresponding to the instructed value Ip, and when the signal N is inputted, a firing angle is applied to a gate distributor 11. The distributor 11 applies the firing angle through a gate circuit 12-1 to the rectifier 3-1, and controls the rectifiers 3-2-3-4 to ON or OFF through the following gate circuits 12-2-12-4. In this manner, the variation in the current of the motor can be reduced.</p> |
