| 摘要 |
PURPOSE:To obtain a torque-speed characteristic equivalent to that of a combustion engine automobile or an induction motor electric automobile and to operate an electric automobile with a weak field so that the automobile can be reduced inn size, weight, and cost and can be improved in efficiency without increasing the motor current. CONSTITUTION:The current I of a motor is controlled by changing the d-axis component of the current I to zero and the q-axis component of the current in accordance with the torque T of the motor by raising the output voltage (motor voltage E) of an inverter in accordance with the rotating speed of the motor within a range from the zero rotating speed to a rotating speed N1 and, at the same time, controlling the torque T so that the torque T can become the maximum over a fixed domain. In a domain where the rotating speed of the motor is higher than the N1, the output voltage of the inverter is maintained at the highest voltage corresponding to the voltage of a battery and, at the same time, the phase of the output voltage of the inverter against the induced voltage of the motor is controlled so that the magnitude of the q-axis component of the current can become the value corresponding to the torque T. |
