CALCULATION OF THE SHORT-CIRCUIT REACTANCE OF TRANSFORMERS BY A LINE INTEGRAL BASED ON SURFACE MAGNETIC-CHARGES

An efficient approach for calculating the short-circuit reactance of t ransformers is presented in this paper. This approach is based an the surface magnetic charge method and the band-ring mesh elements. The ar ea integral in the calculation of the magnetic flux is transformed to a line integral, which can save on computing time and increase the cal culation accuracy. The integral transformation results from the idea o f the flux decomposition. Furthermore, based on the nux decomposition, a unified formula of calculating the short-circuit reactance of trans formers is derived. The calculation of the formula is simplified by em ploying the band-ring boundary elements in the particular geometrical situation that the cylindrical windings and the elements are coaxial. Calculation examples illustrate that the approach presented in this pa per is both efficient and accurate.