METHOD FOR DETERMINING PARAMETERS OF THREE WINDINGS TRANSFORMERS AND VARIACS THREE-RAYED EQUIVALENT CIRCUIT

摘要

FIELD: electricity.;SUBSTANCE: short circuit tests determine the short-circuit voltage and the losses of active short-circuit power. Then, the active resistances of the equivalent circuit rays are formed by the expressions: ; ;the inductive impedances of the replacement circuit are formed by the expressions:; ;where u_kV-S, u_kV-N, u_kC-N - short-circuit voltage across the pairs of windings marked in the indices, for the autotransformer u_kV-H, u_kC-H are given to its nominal power, pu, ΔP_kV-S, ΔP_kV-N, ΔP_kC-N - the values of active power losses in case of short-circuiting in pairs of windings, noted in the indices, for the autotransformer ΔP_-kV-N, ΔP_kC-N are given to its nominal power, W, U_Vnom, U_Snom, U_Nnom - nominal voltages of high, middle and low sides of the transformer, autotransformer, V, S_t.nom - the nominal power of the transformer, VA. The coefficients of transformation of the medium and low voltage branches of the equivalent circuit are formed by the expressions:; .;EFFECT: elimination of errors in determining the parameters of a three windings transformers three-rayed equivalent circuit.;8 tbl, 4 dwg