METHOD FOR DETERMINING DAMAGED POINT OF POWER TRANSMISSION AND COMMUNICATION LINES Russian patent published in 2015 - IPC G01R31/11 

FIELD: electricity.

SUBSTANCE: invention is referred to the electric power industry and may be used for the development of devices intended for the determination of a damaged point in power transmission and communication lines. The concept of the invention is as follows: harmonic oscillations of a different frequency are emitted into the line in a sequence in time. Reflected signals are received. Reflection indices "Г"(f_i) are defined against the received reflected signals. The reflection indices are multiplied by M values $$e^{j\frac{4\pi \cdot f_n{x}_m}{V"ф"}},$$ where x_m=x_min+m·Δx, Δx is an increment (value discrete), x_min is the lower boundary in the area of a potential defect. The received M values are stored up. The power of the reflected signals is computed twice as per the following formulas: $${\left|U_{m1}\right|}^2={\left|{\displaystyle \sum _{i=1}^N{A}_nГ(f_i)e^{j\frac{4\pi f_i{x}_m}{V_{"ф"}}}}\right|}^2$$ and $${\left|U_{m2}\right|}^2={\left|{\displaystyle \sum _{i=1}^{N_1}{A}_n"Г"(f_i)e^{j\frac{4\pi f_i{x}_m}{V_{"ф"}}}}-{\displaystyle \sum _{i=N_1}^N{A}_n"Г"(f_i)e^{j\frac{4\pi f_i{x}_m}{V_{"ф"}}}}\right|}^2,$$ where 1<N₁<N. Then a value for the power of the reflected signals U_m is defined as the difference of the first and second power values excluding negative values: $${\left|U_m\right|}^2=\{\begin{array}{l}{\left|U_{m1}\right|}^2-{\left|U_{m2}\right|}^2{\left|U_m\right|}^2>0\\ 0{\left|U_m\right|}^2\le 0\end{array},$$ and the damaged point is identified against the maximum value.

EFFECT: potential identification of weak defects placed close to the main defect.

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