SPEED CONTROLLING DEVICE FOR ELECTRIC MOTOR VEHICLE

摘要

PURPOSE:To improve the torque balance of an electric motor vehicle by introducing a constant current control by a current pattern to the control region of a constant voltage variable frequency. CONSTITUTION:A subtractor 10 applies a deviation between a current pattern responsive to the rotating speed of an induction motor 5 outputted from a pattern generator 13 and the actual current to a pulse width modulator 8. An adder 9 adds a slip frequency command fS and the rotating speed of the motor 5, and applies the addition to the modulator 8. A subtractor 11 adds a deviation between the pattern from a pattern generator 13 and the actual current to the frequency fS in the control region of constant voltage variable frequency. In this manner, the current control in the control region of constant voltage variable frequency is performed by controlling the slip frequency, and large torque unbalance between controlling units can be avoided.