Research on Optimization of Electric Pneumatic Combined Braking Control for Urban Rail Transit Trains

The braking control system is a key component of metro vehicles, and the braking capacity of metro is the fundamental guarantee of metro operation safety and transportation capacity. Due to the characteristics of frequent starting and stopping, short station spacing and large passenger capacity change during the subway operation, the subway braking system is required to have higher performance, quality and sensitivity. But the brake system is highly integrated and complex in structure, so it is very difficult to develop, design and experiment teaching. In order to solve the above problems, an experimental system that can simulate the braking process of metro vehicles is developed by combining software and hardware. With the rapid development of rail transit, the requirements for train traction system and braking system are becoming higher and higher. In order to develop a high-performance traction and braking control system, on the premise of in-depth analysis of the functions and operation modes of the electric traction and electric air combined braking test platform, the construction methods of the AC, DC and AC electric traction test platform and the electric air combined braking test platform which are fed with each other at the AC side and used for different driving modes are proposed. And put forward the specific operation control mode of the development test platform.

I. Introduction

In order to improve the running speed and ensure the running efficiency, the train is required to have a large starting acceleration; In order to achieve accurate parking and instant speed regulation, it is necessary for the train to have a stable deceleration. Therefore, subway vehicles must rely on the brake control system to adjust the train running speed and stop at the predetermined place timely and accurately during high-speed operation. The distance between stations during subway operation is relatively short, the start stop and speed regulation are frequent, and the passenger capacity and vehicle weight vary greatly. To ensure the safe operation of the train, it is necessary to require the vehicle to have high braking performance. The stability and reliability of the braking system will directly affect the personal safety and travel experience of passengers. The braking system of urban rail vehicles is the key to the safety and accurate parking of vehicles. Since the birth of rail trains, braking technology has always been the focus and difficulty of scientific research, involving a wide range of knowledge and complexity, and with the improvement of train operation speed, the requirements for safety performance are becoming higher and higher. Nowadays, the development of urban rail manufacturing industry in India has taken the lead in the world. However, most of the subway braking systems have introduced foreign technologies, and there are few technical experience and professionals. The development and design of braking technologies are still slow. Many universities, enterprises and scientific research institutions are still doing a lot of research work in this field. It is urgent to develop and design a high-performance braking system with independent property rights, so it is particularly important to study the braking control logic and each component of the braking control system. Based on the above reasons, this topic has completed the design of the subway braking experimental system, which uses PLC instead of microcomputer as the controller to realize the simulation of the subway braking process. This will be of great help to the theoretical study of braking technology and the research of braking simulation technology. It can not only reduce the cost of research and development experiments, but also improve the efficiency of scientific research, which is of great significance to scientific research and teaching.