Two independent methods for power transformers vibration control

Power transformers´ on-line vibration control has its limits in relation to noises influence coming from mechanical components of transformer (pumps, motors); implementation of harmonics analysis helps to increase the control reliability. Implementation of capacitive currents´ to ground harmonics analysis allows increasing the reliability of vibration defects location. This becomes possible due to magnet core vibration which gives spectral lines into capacitive current with the same frequency as on-tank vibration measurements. Practical results from two independent methods are given in this paper: - capacitive current to ground harmonics analysis on transformer; - harmonics analysis of vibration velocities registered on tank.