Abstract:
Damage of distribution transformers is an important factor that affects reliability of power systems. By this reason, the remedies of transformer problems are complicated and take time to resolve. Consequently, transformers have to be improved the high-quality of administrations in the design process, manufacturing, and maintenance for expanding life time of the transformer which depends on various factors.
In this thesis, a selected distribution transformer has been simulated by using MATLAB/simulink and finite element method (FEM) programs to show an electromagnetic force occurring inside a transformer during normal and short circuit conditions. MATLAB/simulink program was utilized to create a magnetic circuit model comparing to FEM program which was used to draw a transformer structure. The flux density is calculated from each program that was used to determine electromagnetic force in the distribution transformer.
This study demonstrated that, in normal and short circuit conditions, the electromagnetic forces simulated from MATLAB/simulink and FEM programs were slightly different in axial force about 44%, which affects flicking of coils in axial core of transformers. Regarding, there are many different parameters in each program which is calculated the electromagnetic force. Hence, different transformer simulation programs may provide different expected results. Consideration of appropriate simulation program is important to estimate a hold operation of transformer.