Improved Analytical Calculation of Winding Capacitance Using Correction Factors

Hybrid Analytical-FEM Approach for Power Transformer Transient Analysis

“…The capacitances between winding turns are calculated using the approach presented in reference [5]. The turn-to-turn capacitances are calculated between adjacent turns with significant capacitive coupling using simple analytical formulas for plate and cylindrical capacitors.…”

“…The goal is to obtain the approximation of integral: (5) in closed-form to enable calculation of L matrix on turn level in acceptable time range. Function G(φ) is equal to integral of Q(r, R, z, Z, φ) with respect to variables r, R, z, and Z.…”

“…• The function is monotonically decreasing. To get the approximation of integral (5), numerous calculations of G func [7], were performed. Then, integral value is expressed using the rational func and denominator polynomials were obtained using the least squares method is equal to zero.…”

“…To get the approximation of integral (5), numerous calculations of G function's integral, using [7], were performed. Then, integral value is expressed using the rational functions, where the coeff and denominator polynomials were obtained using the least squares method: corresponds to the coils that are close to each other.…”

“…There can be over thousands of turns in transformer windings, so methods that enable fast calculation are used. Capacitances are calculated using the analytical formulas and correction factors based on numerous 2D FEM calculations [5]. The inductances are calculated using the semi-analytical approach, based on work presented in papers [6][7].…”