Abstract
This paper presents a novel online diagnostics method capable of detecting winding deformations in two-winding single-phase transformers. The main idea is to identify changes in the short-circuit impedance. The combination of 3-D Lissajous curve methods with a Butterworth low-pass filter allows for the accurate determination of winding deformation of large power transformers in real time. The method is very robust and capable of detecting deformations at the early stage even when the measurements are noisy. Only information already available to the differential protection relay is needed. The proposed diagnostics method has been validated with circuit and finite-element simulations plus a lab experiment. The results show that the proposed online diagnostics technique has the ability to identify winding deformation problems under severe conditions, such as nonsinusoidal input, nonlinear loading, and measurement noise. Under ideal conditions (no signal noise), the inductive identification error of the proposed online diagnostics method identifies the parameters with less than 0.09% error. When accepting a measurement noise of 1%, the error on the identification of inductance is less than 0.13%.
Original language | English (US) |
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Pages (from-to) | 600-609 |
Number of pages | 10 |
Journal | IEEE Transactions on Power Delivery |
Volume | 33 |
Issue number | 2 |
DOIs | |
State | Published - Apr 2018 |
Keywords
- Lissajous curve methods
- measurement noise
- non-sinusoidal excitation
- nonlinear loading
- two-winding single-phase transformers
- winding deformation detection
ASJC Scopus subject areas
- Energy Engineering and Power Technology
- Electrical and Electronic Engineering