Study On The Ambient Vibration And It’s Isolation Of Operating Transformers In Residential Districts

With rapidly developing process of urbanization, along with the urban planning and land limited, distribution room as a important electric power place will be more and more sited inside the office or dweller building area of cities.Electrical equipment operating such as transformers within distribution room can produce pollution of the environmental noise, meanwhile, the body will produce the vibration and it will be spread out through the base, the ground and building structure component (board, beam, column, wall and so on). It will not only inspire vibration environment pollution, but also can induce structural noise.Increasingly concerned about the quality of people’s life today, it has a positive meaning obviously for the research on the producing mechanism, the propagation, or the design and controlling of isolation to the environment vibration caused by transformers.Basing on the project to "The Research of Governance on The Structural Sound Transmission Caused by Transformers and Distribution Structure for a Municipality", some research works are carried on to the environment vibration caused transformer inside district. Main contents are as follows:1.Based on the systemic analysis of the related literatures at home and abroad, the vibration mechanism and its propagation law were expounded in detail. There was also a detailed description of measures for vibration and noise reduction in this paper.2.The spectrum characteristics of ambient vibration were found after the field testing on residential districts transformers in a municipality. The vibration frequencies were100Hz and its multiple. So it’s a high frequency vibration. Some structures near to transformers, such as floor slabs, beams, columns and walls, produced new micro vibrations because of the operating of transformers. The vibration attenuation was not obvious in a short distance.3.Considered frame buildings as research objects. In the analysis, the finite element method was adopted and the vibration signal which was got by the field testing was applied to the models. After a dynamic time-history analysis, there was a detailed discussion on the choice of computation method, damping parameters and so on. It was concluded that the micro vibration produced by the transformers working on the basement floor decreased in three directions, and the vibration had influence on the neighbor room only. 4.There was a case of a single layer isolation system of the transformer in a residential quarter. It revealed that one of the most important influence factors on high-frequency isolation effect is the non-rigid foundation after using the four-end parameter analysis method. So a double layer isolation system was raised, and the whole performance got greatly improved in high frequency region. The chose of the intermediate mass, the stiffness ratio and the damping ratio were also discussed.