Signal Processing Technology for Measuring Transformer Winding Deformation Based on Frequency Response Method

When measuring transformer windings using frequency response method, there will be a lot of stray signals generated due to the presence of transformer power frequency current. At the same time, when Rogowski sensors measure current, the measured voltage signal requires the action of an integrator to restore the signal. This article simulates and analyzes the Rogowski coil, and conducts simulation analysis and experiments on the required integration circuit and weak signal conditioning circuit. By using a composite integral circuit to compensate for the dynamic characteristics of the differential signal measured by the sensor, a wideband signal measurement of 1Khz-1Mhz is achieved. Using a fifth order Butterworth filter and amplifier, the 50Hz power frequency signal is attenuated by 74dB, and the frequency response signal is amplified by 46dB. Thus, the frequency response curve can be drawn through clear frequency response signals and the deformation of the transformer winding can be determined.