Study On Simulation Of The Physical Fields Of Oil-immersed Power Transformer And Its Application Base On Maxwell

In recent years, with the rapid development of economic and the constant improvement ofthe level of living in our country, the electricity demand has developed rapidly. It is the only wayto solve the sustain development of the electricity demand by constructing gradually anddevelopment of special high voltage of power grid. In the power grid construction, oil-immersedpower transformer which is not only the one of the main power transmission equipment, but alsoas the one of the most important power system electrical equipment has applied widely. Atpresent, the large-capacity and ultra high voltage, that is one of direction of the development ofpower transformers. With the expansion of transformer capacity, the voltage level of increase, wemust take full account of transformer insulation, loss and temperature issues. Therefore, it hasalso been more and more attention on the study of these aspects.The numerical analysis is the main method which is used to analyze the problem ofelectromagnetic field and temperature field of oil-immersed power transformer at present.Because of it applies to a variety of media, solving and computing speed, high precision, thefinite element method is one of the most widely used among these methods. Ansoft Maxwellwhich is used in this paper has used for this algorithm.As an example, this paper has established a two-dimensional simulation model of the actualoil-immersed power transformers which is according to the structural characteristics of thetransformer, the main technical parameters and a reasonable simplification and assumptions. Itanalysis on the distribution of electromagnetic fields, leakage magnetic field and temperaturefields of oil-immersed power transformer winding by using Ansoft Maxwell finite elementsimulation software.First of all, this paper not only analyzes the electric field and the electric field strength oftransformer winding at the rated voltage from the distribution of the electric field, but alsoanalysis on the distribution of electric field under the distribution of the three forms full-voltagewhich is the frequency alternating voltages, lightning impulse voltage and operating over-voltage;Secondly, the paper analyzes the leakage magnetic field distribution of transformer winding andthe eddy current loss of winding caused by the leakage magnetic field distribution; Once again,the paper is further analyzed the distribution of temperature field of winding based on the eddycurrent loss of winding. In addition, from the perspective of applied research projects, the paperfocuses on the electric field strength and insulation problems at the terminal of windings. It proposes several corresponding measures for reducing the maximum electric field strength andreinforcing insulation at the terminal of windings. To reduce the winding eddy current losses, thepaper proposes three improved leakage magnetic field distribution of the measures and improvethe temperature distribution of the winding by reducing heat. Finally, the model is applied topractical engineering research, which is comparative analysis of different operating life of thetransformer temperature distribution from the actual operation of the transformer. The simulationresults and measured results are matched to the actual test.Therefore, the result of simulation provides a reference value of the insulation electricalstrength at the terminal of oil-immersed power transformer, the calculation of theelectromagnetic parameters and the distribution of temperature field in practical engineeringresearch, and it has a certain reference of the early fault detection and diagnosis of thetransformer.