电力变压器绕组振动及传播特性研究

To further investigate the mechanism of winding radial vibration as well as vibration propagation characteristics in oil, this paper establishes the radial vibration model based on Euler-Bernoulli beam and the model of vibration propagation in oil, uses laser vibrometer and accelerometer to study the winding radial vibration, axial vibration of clamping plates. Meanwhile, the vibration-power-ratio is used to describe the vibration propagation characteristics under different load currents. The experimental results on a single phase transformer with 10kV show that the winding radial and axial vibration of clamping plates share the same order in magnitude. This means both of the axial and radial vibration play important roles in vibration propagation. The amplitude of vibration propagated to tank decays with the increase of distance and the incident angle to tank wall, which make the tank vibration mainly affected by the winding vibration in the adjacent area. As for the propagation path, the oil tank vibration is mainly from the solid under the condition of light load. However, with the increase of the load current, the vibration power on tank increases from oil propagation. A high signal-to-noise ratio can be obtained by selecting the surface of the oil tank near the strong-vibration region. The conclusion can provide an important basis for the detection of transformer winding mechanical state based on the vibration analysis method.