Temperature rise of a dry‐type transformer with quasi‐3D coupled‐field method

Abstract

A quasi-3D coupled-field method is introduced and applied on a ventilated dry-type transformer to study temperature rise of windings in this study. A simplified 3D model was first established to calculate energy loss of core and velocity distribution in a plane above the lower yoke. Then two accurate 2D models were built up to figure out energy losses in the windings. With a combination of indirect and sequential coupling, energy losses of both windings and core were used as heat source, and velocities for both 2D models were applied as boundary condition for analysing fluid-thermal field. Final results of temperature rise were calculated with temperature rise of two 2D models. In the end, numerical results were compared with experimental data to prove the effectiveness of this method.

Optimum Methods of Thermal-Fluid Numerical Simulation for Switchgear

“…The temperature error index is not large in the transitional fluid zones surrounding the current-carrying part, although there is strong heat exchange. Because the small mesh size of handcart, grounding switch, and busbar limits the element size V cell in (17), maintaining the geometric consistency between the geometric model and the mesh. Likewise, the distribution of velocity error index mainly concentrates near solid surfaces and in narrow regions where the airflow is more complicated with large velocity gradient.…”

“…Actually, numerical error results from the difference between the assumed distribution of freedom which is described by interpolation and the actual field in control volumes. (16) Assuming that the numerical error is proportional to the nonlinearity of freedom [16], the posterior error index can be defined as (17). Item 2 represents the degree of nonlinearity of and V r/2 cell is the size coefficient of each control volume, taking the influence of volume size on interpolation error into consideration.…”

“…Eddy current field is used to solve the heat source distribution in this section. The governing equations are [17]…”

3D temperature field of high‐temperature gas cooled reactor cooling medium drive motor and ventilation structure improvement

“…To investigate the temperature rise of each motor component intuitively, which determines the data points for the improvement schemes, we selected No. 1,No. 3,No.…”

“…Thus, it can be observed that during the gradual improvement process of ventilation cooling, each improvement scheme needs to solve two complex numerical functions again. In recent years, multi-dimensional finite-element analysis method has been widely used in the calculation of the temperature field [1][2][3][4][5]. The use of the fluid-solid coupling method [6][7][8][9][10][11][12][13][14][15][16][17] provides a more accurate analysis of various factors contributing to the calculation of the temperature distribution in the ventilation cooling system; however, the calculation of some complex parts (such as the end region of the motor) is complicated, which influences the calculation efficiency.…”