Research And Development On Key Technology And Fault Diagnosis Of Locomotive Control System Power Supply

China railway Construction has achieved the strategic objective of development recently, and the level of locomotive equipments has already been advanced significantly. The speed and volume of railway vehicles have entered the leading ranks worldwide. The immediate consequence of the development of railway is the new demand for safety and reliability advance of the train. The control system power supply of locomotive plays a key role in protecting the safety of railway vehicles as the power source of the control core of the train. The Collapse of locomotives control system is highly related to the stability of the power supply. Therefore, it has great meaning to implement research on the key theory and fault diagnosis of high frequency locomotive control system power supply.Based on the high frequency soft-switching and fault diagnosis theory, this paper aims at Chinese electric locomotives as the objective, the development direction of Chinese railway as well asconducted intensive research on key theory and fault diagnosis of high frequency locomotive control system power supply integrating the characteristics and needs. The main content of this paper includes the following.After finishing in-depth research of operating condition and the load characteristic of the locomotive control system power supply. A novel converter topology is proposed which is based on analysis and practice of various types of DC converter topologies. The operations and characteristic of the new topology are presented in detail. This structure suits high output power applications well. Due to the soft-switching of all the switches and the high clamping voltage which doesn't need to pre-store energy, the new topology has advantages in several aspects such as effective ZVZCS and load range, maximum duty cycle and minimal duty lost.To control the new topology, this chapter proposed a new immune feedback PID controller with the consideration of highly nonlinear and time-variable characteristic of the locomotive control system power supply. The experimental result shows that the new controller's performance is ascendant over the traditional PID controller in time variable and complexity models, it is hardly influenced by the parasitic parameter varying. The new controller has minimal overshoot as well as none static error, and it also has a rapid response rate to the load surge. The application of the sample indicates that, the practical performance of the new PID controller and the new switching power supply has the anticipatively excellent performance.Based on the prototype of newly proposed locomotive control system power supply, this chapter proposed a distributed fault diagnosis theory utilizing the causal models. The new theory is proposed to solve the huge calculation amount problem, as well as the lack of precise mathematic system model and analysis method for parasitic parameter. The proposed method cuts the original system into several causal independent subsystems, so as to diagnosis system fault locally, in this situation, the amount of parameter and structure variables that involved in diagnosis has been significantly reduced, therefore the complexity is much lower and the reliability is much higher. On the other hand, it can utilize the most suitable diagnosis method to different subsystem, which will achieve the highest diagnosis accuracy.According to the devolvement need of locomotive control system power supply and based on the three key theories discussed above, this chapter mainly concerned on the modularity and parallel operation theory. On the base of theory research, this chapter proposed a parallel operation mode using current balance technology., Both voltage and current control loop of the power supply are achieved by implementing max current balance method, the experimental results show that the output characteristic and current Equilibrium level are great.At last, based on all the theory research, as well as the large amount of simulation and experiment, a novel locomotive control system power supply with fault diagnosis function is built, and has been installed on HXD30132I locomotive.