Electric Locomotives Network Of Electrical Control System Design

The electric locomotive which plays an important role in the construction of thenational economy, it is also the major transportation mean and people like it. It is suitable forChinese national conditions because of its long developing time, technology mature,maintatnancefree, huge traffic volume. So it is reasonable to develop and perfect thelocomotive in order to make it more advanced and the trend of the development of Chineserailway system will be: big start traction of AC drive locomotive, wide constant power range,high power factor, low equivalent disturbing current.This paper based on the analysis of the Chinese present locomotive electric controlsystem structure, we purposed the implementation scheme based on PROFIBUS networkelectric control system. Making S7-300and S7-200PLC as the core control system, underthe guidance of automatic control theory and advanced technology, with a list of specificelectric locomotive to be the controlled object and by the technical program of detection andthe superior monitoring, we completed the design of electric locomotive hardware systemmodel, software system and superior monitoring system and realized the improvement of thecontrol system.Firstly we built up locomotive net work control system by using one train as a model,whose every coach has PLC core and can control themselves respectively using otherperipheral electric equipment. Master station use the S7-300which the head station also use.The rest of the coaches use the S7-200, meanwhile, master stations communicate via thePROFIBUS fieldbus. The head station is responsible for starting,stopping, accelerating,decelerating and so on. The rest of the coaches are responsible for air conditioning, watersupply, power supply and lighting.Besides,the refrigeration control uses frequencyconvertion and the temperature regulation uses closed-loop PID control.