To deal with this problem, the paper proposes a new approach based on the combination of different measured drivingpoint impedances and relevant analysis of the duality-based equivalent circuit in determining frequency dependent parameters associated with transformer windings. Results show that the physical FRA interpretation can be reasonable obtained for the test transformer in low and medium frequency range. | Tạp chí Phát triển Khoa học và Công nghệ, tập 20, số K3-2017 11 Measurement-based electrical parameters of power transformers for Frequency Response Analysis interpretation Part II: Winding analysis Dinh Anh Khoi Pham Abstract— For a practical Frequency Response Analysis (FRA) interpretation applicable to power transformers, frequency dependent electrical parameters of the core and windings in broad frequency range should be identified through nondestructive measurements. Since the core parameters are determined in Part I, electrical parameters of windings (resistances, capacitances) and leakage paths surrounding windings (leakage/zero-sequence impedances) of a distribution transformer will be discussed in this paper. Due to the fact that most parameters associated with the windings currently can only be measured at or around power frequency through diagnostic testing methods, the practical parameter-based FRA interpretation is not possible. To deal with this problem, the paper proposes a new approach based on the combination of different measured drivingpoint impedances and relevant analysis of the duality-based equivalent circuit in determining frequency dependent parameters associated with transformer windings. Results show that the physical FRA interpretation can be reasonable obtained for the test transformer in low and medium frequency range. Index Terms— Driving-point impedance, duality principle, electrical parameters, frequency response analysis, transformer winding. 1 INTRODUCTION E lectrical parameters associated with transformer windings consist of resistances, Manuscript Received on March 15th, 2017, Manuscript Revised on November 01st, 2017. Dinh Anh Khoi Pham, Division of High-Voltage Engineering, Department of Power Systems, Faculty of Electrical and Electronic Engineering, Ho Chi Minh City University of Technology, VNU-HCM, Vietnam (e-mail: khoipham@). capacitances and dual magnetic-electrical parameters such as leakage .
