Development Of Compensating Power Supply Applicable To The Stimulated Device Of Metro Stray Current

Metro stray current causes about seriously harmful electrochemical corrosion in subway rail, rebar in concrete main structure buried underground nearby metro, underground metal pipeline around the Metro, and buildings along the Metro. Up to now, passive "intercepting" and "channeling" safeguard procedures have been taken to prevent Metro stray current from harming and worked in a certain sense. However, the goal of dispelling it has not ultimately achieved. This thesis is devoted to the study on preventing Metro stray current in a positive and effective way. Combining multi-way measuring and automatic compensation, this power supply compensation project covers several fields, including electrons, testing, and electricity protection.The generation mechanism, harm of Metro stray current as well as present shelter measures are introduced in the first part of this paper. Besides, a positive preventing and treating project is put forward in a way to effectively reduce Metro stray current, by compensating stimulated the Metro trail current, the whole process of designing and establishing in the laboratory simulated device of Metro is also discussed; On the basis of analysis of types of the power, a detailed introduction of circuit design and major parameters of key components is woven into three parts: step-down circuit, main circuit and control circuit; Based on the comparison of methods of isolating, a detailed introduction of circuits of gathering, isolating, enlarging devices as well as major parameters of key components some circuit design and key parameters choice of device; The following is a brief introduction of methods and process of circuit-testing.Finally, seven groups of experiment data are collected from stimulated subway rail, followed by a detailed analysis of every group's experiment result. The stimulated device of metro stray current can better stimulates the actualsituation, and power-compensating device can reduce simulated rail current of "compensated sector" more successfully. Therefore, it can be safely claimed that this kind of preventing and treating scheme is rational and feasible. Subsequently, a good foundation has been founded for further research on the use of Controlled switching-mode power supply in actively compensating current.