CONTROL APPARATUS FOR ELECTRIC CAR

摘要

An electric car has powered drive (and braking drive) controlled by controlling the current through n d.c. motor by means of an on-off chopper. When the car is below a predetermined speed the field coil of the motor is in series connection with the armature to achieve full field control. When it is above the predetermined speed the field coil is changed-over to shunt connection to achieve weak field control. The duty cycle of the chopper is controlled by the running state of the car in order that the field current after changeover from series to shunt connection nay become substantially equal to the value, thus suppressing the transient change of the current.