Power transformer rupture and fire resulting from an arcing fault inside the tank usually leads to significant security risks and serious economic loss. In order to reveal the essence of tank deformation or explosion, this paper presents a 3-D numerical computational tool to simulate the structural dynamic behavior due to overpressure inside transformer tank. To illustrate the effectiveness of ...

Magnetic core saturation of transformers and rotating machines generate harmonics. Harmonics are integer multiples of the fundamental frequency. Harmonics is caused by nonlinear devices in the power system. Due to the non-linear loads, power frequency harmonics exist mainly in distribution systems. The current harmonics cause voltage harmonics, hence resulting in nonsinusoidal supply voltage in...

To study the temperature rise of dry-type transformer in different cooling conditions, finite element method is used in this paper to calculate temperature distribution in the transformer. Firstly, thermal-fluid coupled model of a transfomer is built up,and the equivalent heat generation of this model is figured out according to the results of delivery test. Then, thermal-fluid coupled model is...

In this paper, a new model has been presented to determine the number of spare transformers and their locations for distribution stations. The number of spare transformers must be so that they need minimum investment. Furthermore, they must be sufficient for replacing with transformers that have been damaged. For this reason, in this paper a new purpose function has been presented to maximize p...

This paper presents an Integrated Management System of DistributionTransformer Loading using a relational database and loss of life estimation through artificial neural networks. This fully integrated software solution allows for technical personnel to carry out studies of transformers data, such as load curves and loss of life. It permits the analysis of these results by location and substitut...

(Received: October 30, 2011; Accepted: December 8, 2011) Abstract: This paper presents a novel technique for transformer differential protection to prevent incorrect operation due to inrush current. The proposed method in this paper is based on time-frequency transform known as the Wavelet transform. The discrete Wavelet transform is used for analysis the differential current signals in time an...

This paper takes a typical 220 kV three-phase three-limb oil-immersed transformer as an example, this paper building transient field-circuit coupled model and 3D coupled magneto -fluid-thermal model. Considering a nonlinear B–H curve, the magneto model uses the field-circuit coupled finite element method (FEM) to calculate the magnetic flux distribution of the core and the current distribution ...

Renewable energy resources and new loads—such as electric vehicles—challenge grid management. Among several scenarios, the smart transformer represents a solution for simultaneously managing lowand medium-voltage grids, providing ancillary services to the distribution grid. However, unlike conventional transformers, the smart transformer has a very limited overload capability, because the junct...

This paper provides a new approach for power flow and modeling analysis of three phase unbalanced radial distribution systems (URDS) using the simple forward/backward sweep-based algorithm. A three phase load flow solution is proposed considering voltage regulator and transformer with detailed load modeling, for the transformer modeling symmetrical components theory is used and zero sequence-vo...