Article

Reducing Losses in Distribution Transformers

Virginia Polytechnic Institute and State University
IEEE Power Engineering Review 10/2002; 22(9):61-61. DOI: 10.1109/MPER.2002.4312601
Source: IEEE Xplore

ABSTRACT This paper examines three methods of reducing distribution transformer losses. The first method analyzes the effects of using aluminum electromagnetic shields in a distribution transformer. The goal of placing electromagnetic shields in the distribution-transformer tank walls is to reduce the stray losses. A 500 kVA shell-type transformer was used in the experiments. The overall results presented indicate that stray losses can be considerably reduced when electromagnetic shielding is applied in the transformer tank. In the experiment, the tank walls were lined with aluminum foil. The possibility of reducing the dielectric losses was shown through experiments in the second method. The third method analyzes the behavior of wound-cores losses in distribution transformers as a function of joint configuration design parameters. The joint configuration used in this paper is called step-lap joint.

1 Bookmark
 · 
533 Views
  • [Show abstract] [Hide abstract]
    ABSTRACT: An optimal mutual configuration of coils and cooling ducts for the effective cooling of a dry-type transformer is presented in this paper based on the method developed by the author. In the optimization procedure, a computational fluid dynamics (CFD) and a genetic algorithm are combined to optimize the diameters of both the ducts and the coils. The method was applied to cool a special dry-type unit to minimize the hot-spot temperature of the windings. These simulations were performed using various sets of optimized shape parameters and copper mass constraints in a real 3-D transformer geometry. The objective function value is computed using a CFD model that accounts for all three heat transfer modes. In the proposed model, the thermal properties of the coils and core are treated as anisotropic and temperature-dependent quantities, and the power losses are treated as heat sources and are computed based on the coupled CFD-electromagnetic (EMAG) model. Due to a shape change, both coil properties and power losses vary with each generated coil configuration. The results show that the nonuniform positioning of the wires and air ducts and an optimal splitting of high- and low-voltage coils can significantly lower the hot-spot temperature and improve the heat dissipation in comparison with current transformer designs.
    Applied Thermal Engineering 01/2013; 50(1):124–133. · 2.62 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Environmental concerns have resulted in distribution companies becoming more cognitive of the amount of carbon emissions they produce. Research has shown that distribution transformer losses comprise a significant amount of the overall losses on a distribution and transmission system. Although some of the losses are considered the cost of operations, it may be possible to reduce the total losses associated with overloaded transformers depending upon the amount of overload and the efficiency of the replacement transformer. Through the use of a Smart Grid monitoring system, overloaded distribution transformers can be identified for replacement as soon as loads become sufficient to shorten the expected life of a transformer. This paper examines how to utilize a Smart Grid monitoring system in conjunction with loss of life calculations to identify overloaded transformers. Also described in the paper are the necessary input requirements, algorithm requirements, notification threshold levels, and an economic analysis that is specific to a Smart Grid overloaded transformer replacement program.
    North American Power Symposium (NAPS), 2009; 01/2009
  • [Show abstract] [Hide abstract]
    ABSTRACT: In this paper, A transformer capacity and loss on-line detecting experimental system is presented. The on-line detecting methods used in this system are proposed based on the off-line detection research. Two components of the system, a data acquisition system and analysis software on PC, are designed and a simulated experiment platform is also set up. The on-line test of the capacity and loss of distribution transformer using the on-line detecting system is implemented on this platform. The experiment results show that the errors between the on-line and off-line detections are very small and the proposed on-line detecting methods of the transformer capacity and loss are feasible.
    01/2011;

Full-text (2 Sources)

Download
45 Downloads
Available from
Jun 3, 2014