Research On Traction Control Strategy Of Computer System Of DF7G Diesel Locomotive

The performance of the microcomputer control system directly affects the overall performance of the locomotive, as the control core of the modern diesel engine. Traction control strategy is the key and core of microcomputer control,traction performance of Locomotive and traction control strategy are inseparable.So it is very important to study the traction strategy of the computer system of diesel locomotive.The main research contents of this paper are as follows:(1) The traction control strategy of microcomputer system is closely related to the traction characteristics of DF7G diesel locomotive. So this paper first analyzes the traction characteristics of DF7G diesel locomotive to clarify the necessity of adding the middle part, which is the electric drive. According to the analysis of electrical transmission characteristics, two kinds of traction control strategy is proposed in this paper, constant power excitation control and low constant speed control.(2) Mathematical modeling of traction control system for DF7G diesel locomotive is the basis of theoretical analysis and simulation, the mathematical model of the motor driving mathematical model and the electric drive control system of diesel locomotive are established respectively. The mathematical model of the motor driving and each object in the electric drive control system is established separately.(3) After the mathematical model of traction control system is established, it is necessary to select the suitable control algorithm for the traction control system. This paper chose the most widely used PID Control Engineering, analyzes the model of PID algorithm and the setting of parameters. Finally, the improved fuzzy algorithm is proposed for the inertia of the low constant velocity.(4) At the end of this paper is the design and simulation of traction control system platform. According to the actual control requirements of the actual DF7G diesel locomotive, the software and hardware design of the microcomputer control system is carried out. Simulation of traction control system include hardware in the loop simulation based on test platform and dynamic modeling based on Simulink. Hardware in the loop simulation, including analog locomotive general logic control, analog signals, such as the amount of pulse signal, can be carried out on the locomotive traction, fault trigger and other simulation. Dynamic modeling simulation include constant power excitation control system simulation and low constant speed control system simulation. Under constant power excitation control system, the changes of power and speed under various conditions and various disturbances are simulated and analyzed, and the field water resistance test is carried out. The loading situation is simulated in low constant speed control system, how the speed and power change when the load of the locomotive varies linearly. Finally, the fuzzy control algorithm is used to optimize the low constant speed control, and compared with the previous PID control.Through the demonstration and analysis of this paper, the mathematical model of traction control system in DF7G diesel engine is established, the control algorithm of traction control system is put forward, and a control system based on PLC is designed. Finally the simulation analysis of constant power excitation control and low constant speed control is realized.