What are the common speed control methods for mining battery electric locomotives?

2021-10-13

There are three common speed control methods for mining battery electric locomotives: resistance speed control, chopping speed control and frequency conversion speed control.
Resistance speed control refers to adjusting the current size by controlling the resistance of the resistance, and then controlling the output power of the motor, and finally achieving the purpose of speed control.
Chopper speed control also controls the power of the motor by controlling the size of the current, and finally achieves the purpose of speed control. However, its method of controlling current is different from resistance speed control. It changes the average value of the motor voltage and current by adjusting the switching frequency or changing the time ratio of the DC current on and off.
Variable frequency speed control is different from the previous two. It converts direct current to alternating current, and controls the speed of the motor by controlling the frequency of the power supply.
In summary, the essence of mining battery electric locomotive speed control is the control of the electric motor, especially the latter two are both high-efficiency electromagnetic power control. They only have different control objects, but no essential difference.