FIELD: electricity.
SUBSTANCE: sets of instantaneous current values of each phase or two or three windings and voltages of each phase of all transformer windings are recorded for the same instants of time. Actual values of currents and voltages, phase shift angles between voltage and current of windings and between voltages of the first and the second, the first and the third windings are determined. Phase shift angle values between voltages of windings are reduced to nominal supply voltage frequency. Actual values of currents of windings are reduced to nominal voltages of windings. Actual values of active and reactive components of reduced currents are determined. Phase shift angle values between voltages of the first and the second windings, phase shift angle between voltages of the first and the third windings, and actual values of active and reactive components of reduced currents of windings are stored and accepted as base values. Base data is stored not less than for four various loading modes of transformer. Coefficients of equations of two characteristic planes are determined as per base data. As per sets of instantaneous values of currents of windings and voltages of the first, the second and the third windings for any loading operating mode of transformer there determined are phase shift angles between voltages of the first and the second, the first and the third windings and actual values of active and reactive components of reduced currents of windings. As per actual values of active and reactive components of reduced currents of windings, actual values of active and reactive components of reduced currents of windings and phase shift angles between voltages of the first and the second, the first and the third windings, which are determined for one of the base modes, and coefficients of equations of the appropriate characteristic planes there determined are values of base phase shift angles between voltages of the first and the second, the first and the third windings for current loading mode. Relative deviations of phase shift angle values between voltages of the first and the second, the first and the third windings of current mode of values of the appropriate base phase shift angles are determined. State of windings is estimated as per those values.
EFFECT: possibility of performing operative monitoring of transformers under load.
4 tbl, 1 dwg
