METHOD OF DETERMINING SHORT CIRCUIT LOCATION ON ELECTRIC TRANSMISSION LINES Russian patent published in 2018 - IPC G01R31/08 

FIELD: electricity.

SUBSTANCE: invention relates to the electric power industry and can be used to determine the location of a short circuit (fault location) on high and super high voltage power lines in networks with effectively grounded neutral. Essence: the method for determining the short-circuit (SC) location on transmission lines is to measure the transient voltage at the end of the line and use an artificial neutron network (ANN) to recognize the image of the transient process and then establish the distance to the fault location. For the phase-to-phase voltage u_au(t) are calculated with the help of finite differences of the first order derivative where u_au,k and u_au,k+1 – voltage at adjacent (k-th and k+1-th) time samples; h is the step of time sampling. In the derivative of the voltage u', starting from the moment of its appearance (t₀), leave a record length, equal to the double time of the EM wave path (2τ) on a controlled line. Derivative of the voltage u'(t) is limited in amplitude to the value of ±0.1 max(|u'(t)|). From the amplitude-limited derivative u*(t), the low-frequency component is removed by approximating it by a fourth-degree polynomial of the form and subtracting this function from the derivative u*(t), i.e. u**(t)=u*(t)-u_ap(t). From the received signal u**(t) receive the signal-code u_k(t), in which the unit value is set when the signal modulus u**(t) exceeds 0.05 of its maximum value, i.e. u_k(t)=1, if |u**(t)|)>0.05 max(|u**(t)|) and u_k(t)=0, if |u**(t)|≤0.05 max(|u**(t)|). u_k(t) signal code is fed to the input of the trained ANN, which sets the distance to the SC location.

EFFECT: simplified implementation of the algorithm for processing the measuring transient voltage and increased accuracy of the SC location.

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