Brake resistor is a very important resistor. It is widely used in many motor products. With the rapid development of high-speed rail technology, the problem of braking is brought about by the promotion of speed. In order to ensure the safety of trains, brake resistors are introduced to many trains widely so as to improve the safety performance of trains.
 
Train braking is divided into friction brake and non-friction brake before the appearance of brake resistor. Friction braking includes air brake, wheel brake, magnetic rail brake and so on. Non-friction includes: dynamic braking, regenerative braking, resistive braking, eddy current braking, etc. Although the train adopts the combined braking mode of regenerative braking and air braking, the regenerative braking is preferred, the insufficient part is supplemented by air braking, and the electric braking function is maximized as far as possible. However, the application of non-friction braking is still limited by the current vehicle status and foundation design. Therefore, it is generally accepted that friction braking is most effective in emergency braking, which is a more universal and practical braking method. However, for high-speed trains, none of these methods can meet the demand.


High-speed train is a new high-tech product, it has a qualitative leap in speed, the use of brake resistors can effectively ensure the parking safety of the train. In the application of high-speed railway products, the usage rate of brake resistor prescribes the efficiency of braking resistance, in order to avoid the damage caused by overheating of braking resistance, as it will affect the braking effect of braking unit. The lower the usage rate of the brake resistance is, the less the heating degree of the resistance is, the less energy is consumed on the resistance, and the worse the braking effect is. At the same time, the braking unit capacity has not been fully utilized. When the utilization rate of braking resistance is 100%, the capacity of braking unit is fully utilized and the braking effect is the most obvious. However, this requires large power of braking resistor. On the premise that the braking resistance value and power have been determined, a lower resistance utilization rate will achieve a better effect for the slow deceleration of large inertia load. For the load that needs rapid shutdown, it is appropriate to select the larger brake resistance utilization rate.
　
The technology of brake resistors is constantly improving and producing, which is combined with the rapid development of high-speed railway technology, and many researchers have overcome the technical problems when using brake resistors in high-speed trains. The brake resistor is used in the brake system of high-speed railway to protect the higher-speed train and create a new era of high-speed railway safety.