METHOD OF RELAY PROTECTION OF TRANSFORMER Russian patent published in 2017 - IPC H02H7/45 

FIELD: electricity.

SUBSTANCE: method is implemented by using the models of the transformer windings, as well as the models of its magnetic circuit. The information on the observed currents and voltages of all windings, as well as a priori information on the parameters of the windings and the magnetic circuit, is used. The emergency condition of the transformer is recognized by the criterion of adequacy of models to the real object. The protection method includes the observation of currents and voltages readouts, their interpolation transformation into continuous input quantities used in models, the formation of two-dimensional output signals, on the display planes of which the areas of the relay protection operation are set. New are the operations of converting the input values up to the formation of output signals. The first windings are those whose models must be involved at the beginning of the transformations. The input currents and voltages of these models are converted into the derivative of the fluxes of rods on which the first windings are arranged. The models of other windings are used differently. For them, the input values are the derivatives of the magnetic fluxes and the intrinsic currents, and the output values are the voltages at the terminals. Difference voltages are formed, indicating a discrepancy between the voltages obtained as a result of observation of the object and by means of its modeling. The models of independent circuits of the magnetic circuit, in which the magnetic voltage drops are determined, are used similarly. One way of determining them is through the fluxes of rods. The inadequacy of the model and the object is judged by both electric and magnetic difference voltages. Two-dimensional electric and magnetic signals are formed from difference and base voltages. The characteristics of the protection operation are set on the planes of displaying two-dimensional signals.

EFFECT: construction of a universal transformer protection using the available information in the maximally complete facility.

10 dwg