METHOD FOR DIGITAL CORRECTION OF EFFECT OF CURRENT TRANSFORMER MECHANICAL SATURATION Russian patent published in 2019 - IPC G01R19/00 G01R33/12 

FIELD: electrical engineering.

SUBSTANCE: invention is referred to electric engineering and electric power industry for use in relay protection and anti-accident automatics for correction of effect of saturation of magnetic conductor of current transformer. According to the proposed algorithms, for the microprocessor module representing the current signal in digital form, orthogonal components of the vector of the first current harmonic are generated, which are transmitted to the relay protection system. First algorithm based on the comparison of the first and second current derivatives with their previous values and given constants determines time boundaries of the interval of its linear transformation. Second algorithm, on the obtained short interval, filters the first harmonic, for which: a) calculating the ratio of current at the current count to its second derivative, which for the first harmonic is a constant value (-1/w₁²), and for a signal of complex shape - a function of time; b) forming difference of moduli of ratios for complex signal and a priori value mod (-1/w)₁²), characteristic for the first harmonic; c) are calculated based on the known optimization method, in particular, gradient descent (including steepest descent using the "golden section" method) such values of readings, that modulus of difference of moduli of ratios, used as a minimized function, tends to zero, which is characteristic for the first harmonic. Third algorithm, based on the received first harmonic samples, generates orthogonal components of the current vector of the first current harmonic.

EFFECT: technical result is recovery of current signal parameters distorted at saturation of electromagnetic current transformer magnetic conductor.

1 cl, 8 dwg, 3 tbl