What is the braking system of high-speed rail and what does it rely on?

The braking system of high-speed rail is as follows:

The braking control device of each car of EMU is controlled by microcomputer, which consists of electric braking (regenerative braking) and air braking (disc braking) of each car. The braking control device has skid detection function and adopts electric command braking system.

With the increase of train speed, the adhesion factor will decrease, so the braking force of speed-adhesion mode control is set to change with the change of speed.

This mode is set on the basis of adhesion test on the premise of rainy days, so the train can stop at a specified distance and will not slip when braking.

Braking principle

The basic braking devices of motor cars and trailers all adopt booster cylinders and oil pressure disc devices for gas-electricity conversion. Under the grouping of four motor cars and four trailers, the trailers are fully mechanically braked.

EMU adopts compound braking mode, that is, EMU adopts electric braking+air braking, and trailer adopts air braking.

Regarding the switching between regenerative braking and air braking, the braking force is judged by the brake control device through the coordinated control of electricity and air, and when the braking force is insufficient, it is supplemented by air braking.

In order to reduce the wear of brake disc and brake shoe, the delayed control mode is adopted: regenerative braking takes priority, trailer air braking takes second place, and motor vehicle air braking takes third place.

Extended data:

Brake function category

(1) Common braking: Its braking force is divided into 1 ~ 7N for delay control. When the initial braking speed is above 75Km/h, the regenerative braking of the motor car bears part of the braking force of the trailer, and when the braking speed is below 65Km/h, it is switched to independent control, and the control unit is two-car braking.

In addition, with the change of load, the pressure signal can be obtained from the air spring, the braking force can be calculated and adjusted, and the constant deceleration control can be carried out, which does not change with the vehicle load.

(2) Fast braking: the braking force is 1.5 times that of ordinary braking.

(3) Emergency braking.

(4) Snow braking resistance.

(5) Auxiliary braking.

(6) Parking brake: iron shoes are used for parking brake. Generally, during operation, the driver uses the brake controller to operate the common braking (7-bit braking force represented as 1 to 7) and the fast braking. Emergency braking and auxiliary braking are operated by switches under abnormal conditions such as faults. When there is snow, the anti-snow brake is operated by a switch.

Emergency braking distance (idle time of the unit):

When the initial speed is 200km/h, the braking distance is less than 2000 meters.

When the initial speed is 160km/h, the braking distance is below1400 m.