Projeto de uma bancada de testes para avaliação do carregamento detransformadores trifásicos de potência utilizando conversores estáticos

Abstract

This work presents the design of a setup for load tests in power transformers, mainly in adverse conditions. Such operation conditions can reduce life expectancy of the power transformers, mainly if it operates overload for long periods. The overload capabilities depend primarily on the winding temperature. A novel scheme to perform load test in power transformers using reversible power converters is presented. The use of the reversible static converter for the load control of the transformer allows the independent control of the active and reactive power, in both directions, allowing instantaneous and automatic load control as well as voltage regulation. The power spent to perform the test represents only the losses in the transformer, filters and converters. The final goal of designed setup is to allow the test in laboratory, where overload and over-voltage operations can be explored. With this condition, the temperature variation of the transformer windings, insulation and core will be monitored. Simulation results are presented to evaluate the system behavior in order to show that the scheme feasible