| 摘要 |
PROBLEM TO BE SOLVED: To reduce the installation number of resistances of a battery vehicle. SOLUTION: In the state of contacts C1, C2 being closed and a contact C3 being closed to F (forward side) or R (reverse side), a main switching element SW1 is PWM-controlled to control a current flowing to a motor formed of an armature AM and a field coil FC, thus performing speed control. When a weak field contactor C4 is closed, a current flowing to the field coil FC is diverted to a flow dividing circuit formed of a common resistance r3 and the weak field contactor C4 so as to be able to perform field-weakening control. On the other hand, at the beginning of regenerative braking, when a regenerative exciting switching element SW2 is closed at the time of a regenerative contactor C2 being opened, a current flows along a path K13 (a path including the common resistance r3), so that self-power-generation of the motor is established, and regenerative braking can be performed even through the switching element SW2 is opened afterwards. |
