What are the specific differences between the three speed control methods of mining electric locomotives?

2021-10-20

There are three common speed control methods for mining electric locomotives: resistance speed control, chopping speed control and frequency conversion speed control.
Resistance speed regulation, as the name implies, is to adjust the speed of the electric locomotive by controlling the resistance value of the resistance. The way to adjust the resistance is similar to that of a sliding rheostat. Copper contacts are used for commutation and adjustment, so it is easy to damage. At the same time, in order to control the speed during driving, the resistors will be operated in series for a long time, and it is also easy to be damaged by overheating. In addition, because resistance speed regulation generally uses gears, in order to better control the speed of the locomotive, the driver needs to shift gears continuously, which is relatively complicated. The gap between different gears is large, and the starting impact force and current are also large at the same time.
Chopping speed regulation is to adjust the speed of electric locomotive by controlling the on-off frequency or time ratio of the circuit. Compared with resistance speed regulation, it starts and runs more smoothly, has a lower failure rate and relatively simple operation. In addition, the chopper speed controller not only adds a digital voltage display module and a lighting power supply module, but also integrates the control switches of the electronic horn and other parts.
Frequency conversion speed regulation is to achieve the purpose of speed regulation by controlling the frequency of the power supply after converting direct current into alternating current. On the basis of the advantages of chopper speed regulation, its control accuracy is higher, and it can be applied to electric locomotives with greater traction and tonnage. But at the same time, the cost is also higher, and the training requirements for the users are also higher.
The above is the specific difference between the three speed control methods of mine electric locomotives.