RU2013143547A - METHOD FOR EXPERIMENTAL DETERMINATION OF RESISTANCE OF TRANSFORMER WINDINGS - Google Patents

Abstract

A method for experimentally determining the resistances of transformer windings by determining the short circuit resistance of a transformer, characterized in that the short-circuit resistance of a three-phase transformer or a group of three identical single-phase transformers is first measured in the case of primary windings connected first to a triangle, and then to a star, then measured the power values of the three phases P, the average linear values of the voltage U and current I short circuit determine total z, z, active r, r, and reactive x, x short-circuit resistance when connecting the transformer primary winding to a triangle and a star, while calculating by the formulas: ,, r = P / I, r = P / (3I) ,,, then the total, active and reactive short circuit resistance is subtracted in the connection diagrams of the transformer primary winding into a star and a triangle, then these differences are increased by 1.5 times, and the phase resistances of the transformer primary winding are determined by the formulas: Z = 1.5 (ZZ); r = 1.5 (rr); x = 1.5 (xx), where Z, r, x, is the total, active and reactive resistance otivleniya short circuit of the transformer when connecting the primary winding of the transformer to the star; Zr, x - total, active and reactive short circuit resistance of the transformer when connecting the primary winding of the transformer to a triangle.

Claims (1)

A method for experimentally determining the resistances of transformer windings by determining the short circuit resistance of a transformer, characterized in that the short-circuit resistance of a three-phase transformer or a group of three identical single-phase transformers is first measured in the case of primary windings connected first to a triangle, and then to a star, then measured the power values of the three phases P _k , the average linear values of the voltage U _k and current I _to short circuit divide the total z _ct , z _cc , active r _ct , r _cc and reactive x _ct , x _cc short circuit resistance in the connection schemes of the transformer primary winding into a triangle and a star, while calculating by the formulas: $$z_{\mathrm{to}t}=\sqrt{3}U\mathrm{to}/I\mathrm{to}$$

, $$z_{\mathrm{to}s}=Uk/(\sqrt{3}I\mathrm{to})$$

, r _ct = P _c / I _to ² , r _KZ = P _to / (3I _to ² ), $$x_{\mathrm{to}t}=\sqrt{(z_{\mathrm{to}t}^2-r_{\mathrm{to}t}^2)}$$

, $$x_{\mathrm{to}s}=\sqrt{(z_{\mathrm{to}s}^2-r_{\mathrm{to}s}^2)}$$

, then the total, active and reactive short-circuit resistances are subtracted when connecting the transformer primary winding to a star and a triangle, then these differences are increased by 1.5 times, and the phase resistances of the transformer primary winding are determined by the formulas: Z _kn = 1.5 (Z _KZ -Z _CT ); r _kp = 1.5 (r _kz -r _kt ); x _kn = 1.5 (x _short -x _ct ), where Z _KZ , r _KZ , x _KZ , is the total, active and reactive short circuit resistance of the transformer when connecting the primary winding of the transformer to a star; Z _ct r _ct , x _ct is the total, active and reactive short circuit resistance of the transformer when connecting the transformer primary winding to a triangle.