为了解决某城际动车组正线运行时司机显示器无网压、主断路器自动跳开故障,文章分析了高压检测电路的原理及熔断器的工作特性,确定了故障的原因,并提出了相应的优化方案.试验验证和运用考核结果显示,优化后的动车组有效降低了过分相时高压电压互感器单个绕组中的涌流,提高了高压检测电路的可靠性.

Background: For medium and low speed maglev transportation system, the eddy current will be induced in rail, which is made of solid steel, while the train is running. The levitation force of electromagnets will be weakened by the magnetic field generated by eddy current in the rail, especially at the position of the forefront electromagnets. With the increase of train running speed, the eddy current effect will also increase, which will reach 30 % at 100 km/h, and which will directly affect the levitation stability of the train during high-speed running. Put it another way, it will limit the further improvement of the running speed of the medium and low speed maglev train. Aim: In order to solve the above problem, and compensate the levitation force reduced by the eddy current effect. Methods: The FEA method is used to obtain the magnetic field distribution and levitation force changing with the train speed. And taking the middle and low speed maglev trains and rails of Changsha Maglev Express as the research object, we have adopted two solutions, and the prototypes of airsprings and levitation magnets are manufactured and tested in the train. Results: The test result show that the currents of the windings at the front end of the two forefront electromagnets are reduced obviously. Conclusion: In this paper, the medium and low speed maglev train and rail used by Changsha Maglev Express are studied, the eddy current effect is analyzed, and two solutions are proposed. The results show that the solution methods can alleviate the eddy current effects to some extent.

The paper expounds the performance and characteristics of super capacitor 100% low-floor tram running without pantograph,including overall technical performance,main mechanical parts and electrical parts,such as energy storage system,current collect device,car body,bogie,interior decoration,air conditioning and ventilation system,hydraulic braking system,and the characteristics of traction system,auxiliary system,network control system,passenger information system and lighting system.

The article presents the development intention of HTS transformer for electric multiple unit and the characteristics of 300 kVA HTS transformer's prototype,describes the main technical theories of the project research,and puts forward 3 000 kVA HTS transformer's concept design on the base of 300 kVA HTS transformer's prototype development and manufacture.

A new direct torque control method for asynchronous traction motor in low-speed rang is presented.Improved torque ripple control by flux hysteresis comparator and quasi-constant-switching-frequency operation by space vector Modulation are special concerned.The performance of the new method has been verified by simulation test.

Electromagnetic Compatibility(EMC)is an important subject in the research and production of elec-tric lo comotive.Electromagnetic Interference(EMI )in electric locomotive is summarized in this paper.Combining with several examples,some countermeasures are presented.

This article is mainly about fault diagnosis system of type DJ 1 locomotive's concept,construction,and main function of its controlling units supplemented with its information flowcharts.Also this article concisely intro-duces fault diagnosis pro cess of multiple unit condition.