Why is it not recommended to use resistance speed regulation for lithium battery locomotives?

Date:2022-12-21

Why is it not recommended to use resistance speed regulation for lithium battery locomotives?

There are three speed regulation methods for lithium battery electric locomotives: resistance speed regulation, chopper speed regulation and frequency conversion speed regulation. Why is chopper speed control instead of resistance speed control used in more and more lithium battery electric vehicles? This is related to the principle of resistance speed regulation.

As the name suggests, resistance speed regulation is to use resistance to control. The control principle is to use resistance to consume "excess" electric energy, thereby reducing the speed; or reduce the energy consumption of resistance to increase the speed. Based on this principle, it is obvious that a large amount of electric energy will be wasted when using resistance speed regulation, while the energy supply method of lithium battery electric locomotive is battery. Unlike trolley electric locomotives, the power of lithium battery electric locomotives is always limited. Resistive speed regulation wastes electric energy, and the result can reduce the driving distance; if the car is driven with a low battery, the lithium battery electric car may even stop halfway due to insufficient power.

Of course, generally speaking, the energy consumption of resistor speed regulation is only a trivial matter, and generally it will not reach the level of affecting the battery life of lithium battery electric vehicles. Unless, as mentioned at the end of the above, the battery is insufficient before driving. The important reason is that the speed control and steering control of the resistance speed control are all completed through the copper contact head. Every friction is a loss to the parts, and the contact head may be damaged at any time. Although maintenance and replacement are simple, it is also troublesome. Moreover, electric sparks may be generated during friction, which is a potential safety hazard in a working environment with gas.

The above is why more and more lithium battery electric vehicles choose to use chopper speed regulation instead of resistance speed regulation.