Power Transformer No-Load Loss Prediction with FEM Modeling and Building Factor Optimization

Abstract

Estimation of power transformer no-load loss is a critical issue in the design of distribution transformers. Any deviation in estimation of the core losses during the design stage can lead to a financial penalty for the transformer manufacturer. In this paper an effective and novel method is proposed to determine all components of the iron core losses applying a combination of the empirical and numerical techniques. In this method at the first stage all computable components of the core losses are calculated, using Finite Element Method (FEM) modeling and analysis of the transformer iron core. This method takes into account magnetic sheets anisotropy, joint losses and stacking holes. Next, a Quadratic Programming (QP) optimization technique is employed to estimate the incomputable components of the core losses. This method provides a chance for improvement of the core loss estimation over the time when more measured data become available. The optimization process handles the singular deviations caused by different manufacturing machineries and labor during the transformer manufacturing and overhaul process. Therefore, application of this method enables different companies to obtain different results for the same designs and materials employed, using their historical data. Effectiveness of this method is verified by inspection of 54 full size distribution transformer measurement data

Research of dependences of idle losses of transformers TM-400/10 on voltage according to synchronous measurements

“…The actual dependences of NL on voltage can be determined in laboratory conditions or in field tests associated with disconnecting the transformer from the network. An alternative to this solution can be the identification of transformer parameters based on high-precision synchronous measurements [6]. However, the implementation of synchronous measurement technologies in distribution networks requires the solution of many technical problems, including the development of inexpensive measuring systems with the function of synchronous measurements [7,8].…”

Prediction of Core Losses of Three-Phase Distribution Transformer

“…Due to calculation of transformer losses, teNyenhuis et al [7] employed 2-D FDM (finite difference method) to predict flux distribution and magnetic loss in cores with this structure. In spite of high precision, such calculation needs considerable degrees of processing ability [8].…”