| 摘要 |
<p>PURPOSE:To obtain substantially similar characteristics to a cam wheel by reducing torque pattern at the prescribed rate upon rising of the speed of an electric railcar in a weak field controlling range. CONSTITUTION:Since a relay contact 31 is opened in a full field range, a torque command applied to a comparison amplifying arithmetic unit 24 becomes the pattern itself in response to the load outputted from a torque pattern generator 16, and a motor is controlled at the constant torque Ti. When the conduction rate of a chopper 11 increases upon rising of the speed to reach the maximum rate, a switch 8 for field branch is closed so that the motor becomes weak field state, a relay 20 is driven to close the contact 21. In this manner, the output of a pattern generator 8 is inputted through the contact 21 to a subtractor 22, and the torque command is subtracted from the value of Ti by the output DELTAT of the generator 18.</p> |
