| 摘要 |
In a rotary-current locomotive power unit which is driven by asynchronous motors, the following automatic anti-skid protection method is used: by means of a pulse transmitter, the state of the macro-slip between the drive wheels and the rails which occurs when the traction force lies above the limit of the coefficient of friction is detected. In this case, the pulse transmitter produces a control pulse which triggers an instruction for automatic transmission and, directly before that, a reduction of the electrical voltage present at the asynchronous motor. By virtue of this measure, the characteristic torque curve of the motor is changed in such a way that instead of the normal steep progression a flatter progression occurs. In this way, it is assured that the traction force remains near to the effective friction limit without exceeding it. A reduction in the motor power does not take place. |
