Development Of Auxiliary Converter For High Power AC Locomotive

Auxiliary converter is an important part of AC electric locomotive,used to traction cooling fan,car lighting and air conditioning systems,batteries and other cooling equipment to provide electricity,its normal work or not directly affect the safe operation of the locomotive.In this paper,"a new type of electric locomotive auxiliary converter development" as the background,the work of auxiliary converter work principle,design and control strategy.The specific research contents are as follows:(1)The classification of auxiliary converters and several typical topologies are described.The topology and working principle of AC-DC-AC are introduced.The main structures include single-phase PWM rectifier and three-phase inverter variable parts of the two parts,respectively,their working principle and control strategy were studied.(2)The single-phase PWM rectifier uses the double-loop control strategy of the voltage outer loop and the inner loop of the current-side voltage feedforward.The PI controller can not realize the defect of the AC signal without tracking the current inner loop.PR controller to replace the traditional PI controller.MATLAB simulation and experiments show that the PR controller can greatly improve the ability of the inner loop to track the sinusoidal signal.(3)The method of sensor redundancy control is studied from the aspects of improving the reliability of system operation,and the realization principle of this method is expounded.MATLAB simulation shows that the use of this method,despite the control accuracy has declined,but greatly higher reliability of the PWM rectifier operation.(4)The causes of the double-pass frequency ripple on the DC side of the auxiliary converter and the influence on the current-side current control are analyzed,and the digital notch filter is designed.MATLAB simulation and experimental results show that the notch filter can effectively suppress the DC bus voltage in the secondary frequency AC component,improve the current loop control effect.(5)The control principle of constant voltage to frequency ratio(V / f)control is analyzed,and the principle and realization method of low loss five-stage SVPWM modulation technology are analyzed.Simulation of Three-phase Inverter Based on Five-segment SVPWM.(6)The design of the main circuit parameters of the auxiliary converter and the hardware and software design of the electronic control box based on DSP28335 are given in detail,and the related experiments are done on the auxiliary converter,and the theory is adopted.