Research On Wear Mechanism And Strategy For Reducing Wear Of Generator/Motor Electric Brush

At present, it is the key period of constructing the pumped storage power station in China. The electric brush as the important component of unit plays an significant role in the pumped-storage power station. Its performance stability is of great importance to the safety operation of pumped-storage power station units. Especially the research on the brush wear characteristics of the generator/motor has important practical significance. Therefore, in order to solve the engineering problem of serious brush wear, "Research on the wear mechanism and strategy for reducing wear of generator/motor electric brush" is studied in this paper.Electric contact and wear theory are explored and mastered based on research status and engineering background of brush wear in this paper. To find the main factors affecting wear extent seriously, using ANSYS to carry out the simulation and analysis by the brush-collecting ring equivalent model. To obtain relevant rules of relationship between brush wear and main various factors, multi-factor tests are carried out relying on the brush wear test platform with current-carrying. Furthermore, the paper puts forward practical measures to solve the brush wear problems in terms of practical engineering issues.This paper obtains the following results through the above research:(1) By the research on the mechanism and characteristics of brush wear, this paper clarifies the different types of the brush in wear process. In the middle stage of wear with current is mainly electro erosion wear and abrasive wear. (2) To obtain the actually running minimum wear rate by using the orthogonal test method, the results showed that the rate reaches the minimum when using the NG brush, wear pressure being 5.5 X 104 Pa, current density being in 8 A/cm3 and speed being at 800 r/min. (3) The relationship between brush wear rate and current density shows as being the "U" shaped variation rule. When the pressure is about 5.84×104Pa, the wear rate reached near the concave point. (4) This paper proposes solutions:Improve the brush electrical properties by adding the dipping agent; Enhance the processing technic of the surface and groove of the collecting ring; Collocate the brush institution reasonably and design the gathering units for carbon powder.This paper provides the theoretical guidance and technical methods for the study of brush wear. The application of pumped-storage power station units engineering is scientific and reasonable. And it has laid a good foundation for the follow-up study of similar problems.