Study On The Vibration Characteristic And The Vibration Isolation Of Transformers In Residential Districts

Along with the urban planning and land limited, power distribution facilities will be more and more sited inside the office or dweller building area of cities. Follow, 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 machine bases and other structure members. It will not only inspire vibration environment pollution, but also can induce structural noise. Obviously, it has a positive meaning for the research on the producing mechanism, the propagation, or the design and controlling of isolation to the environment vibration caused by transformers in residential districts. The vibration mechanism and the propagation law of dry-type transformers were studied in this paper based on the project to "The Research of Governance on The Structural Sound Transmission Caused by Transformers and Distribution Structure for a Municipality". After that, a systemic analysis was carried out on the design and optimization of isolation systems. The main contents of this paper are described as follows:1. In this paper, a dynamic analysis model was built up with a combination of finite element method and software ANSYS. The natural frequencies and mode shapes were got after the modal analysis on the transformer core, the bottom supported channel steel and the whole structure. It was found that the transformer core and the whole structure would resonate at75-525Hz.2. After the field testing of the ambient vibration of both transformers with isolators or not in residential districts, the acceleration signal delivered to the body and the floor were got. And then the effect of vibration isolation was evaluated. Fast Fourier transform was applied to the signal in order to detect its frequency domain characteristics.3. Based on the non-rigid of transformers, ANSYS was used to carry on a dynamic analysis on the single-layer vibration isolating system. And the influence on isolation effect by the change of the structure parameters was discussed, which laid a foundation for optimizing the system.4. Considering the flexible of the foundation, a special multi-layer vibration isolation system of "Plate-Beam-Mass" was established on the paper. The power flow transfer equation was derived by the "Thevenin equivalent method". After the comparison of effects of isolating systems using numerical method of MATLAB, it was concluded that the "Plate-Beam-Mass" vibration isolating system showed a better performance than single-layer vibration isolating system and multi-layer vibration isolating system. At the same time, the influence between changes of structure parameters to the power flow was discussed systematically, which provided valuable reference for optimizing the system.