CN101551434B - Transformer partial discharge positioning method base on ultra high frequency detection technology - Google Patents

Abstract

The present invention disclose a transformer partial discharge positioning method base on ultra high frequency detection technology. The method includes following steps: utilizing a plurality of discharge detector arranged in the transformer to detect the ultra high frequency discharge signal of the transformer; sending the detected signal to the information collecting center for coding; sending the coded signal to the signal regulating circuit for filtering, eliminating interference and noise signal; sending the filtered signal to the processor, and the processor determining the electricity discharging position of the transformer partial discharge according to arriving order of the detected signal. The invention conquers defects of the common partial discharge detection method of poor anti-interference capability, low sensitivity and low measurement precision, and the structure is simple with high reliability, which can be widely used for high precision measurement of every point partial discharge inside the transformer.

Description

Transformer partial discharge positioning method based on ultra high frequency detection technology

Technical field

The present invention relates to a kind of transformer partial discharge positioning method based on ultra high frequency detection technology.

Background technology

Electric energy is the economic lifeline of country, is closely related with the ordinary production of daily life and enterprise.China is in the peak period and the key period of power construction at present, presses for the corresponding ehv power transmission gordian technique of research and development.As electric system power transmission and transformation key equipment, the reliability service of power transformer is significant to safety, the economical operation of whole electric system.

Mostly large-scale power transformer is oil-immersed power transformer, solid-oil-insulation structure that its insulation system mainly is made up of oil, paper, cardboard etc. at present.Power transformer can form local defects such as bubble, crack, suspension conduction particle and electrode burr in manufacture process, be higher than average field intensity thereby cause insulator inside or surface to go up some regional electric field intensity.When these regional breakdown field strengths are lower than average breakdown field strength, can discharge, and other zones still keep insulation characterisitic, thus the phenomenon of formation shelf depreciation.

Cause insulating material to decomposite phenomenons such as gas with electric pulse, electromagnetic radiation, sound, light, local pyrexia and discharge during partial discharge of transformer, can detect shelf depreciation through these phenomenons.In detection method for local discharge commonly used, pulse current method, DGA method and supercritical ultrasonics technology are to use more widely.

Pulse current method be study the earliest, most widely used a kind of detection method; It detects through impedance being linked into measure in the loop; But it measures the restriction that sensitivity receives mutual impedance, and survey frequency is low, frequency band is narrow, and the quantity of information that comprises is few; And poor anti jamming capability can't effectively be applied to on-the-spot on-line monitoring.The DGA method is to confirm malfunction through the composition and the concentration of all gases that detects transformer oil decomposition generation, but the oil gas analysis is a long-term observation process, thereby can't find catastrophic discontinuityfailure, and this method can't be carried out localization of fault.Supercritical ultrasonics technology is size and the position of coming survey bureau to put through the ultrasonic signal that detects the transformer partial discharge generation, but receives the restriction of the time delay error of ultrasonic propagation, and the accuracy of ultrasonic locating and sensitivity are not high.

Summary of the invention

For the above-mentioned technical matters that the position finding and detection method that solves existing partial discharge of transformer exists, the present invention provides a kind of localization method of the partial discharge of transformer based on super high frequency technique.The present invention can detect the position of shelf depreciation, and accuracy and sensitivity are better.

The technical solution adopted for the present invention to solve the technical problems is:

Detection signal behind the coding is delivered to processor, and processor earlier carries out filtering, eliminates and disturb and noise signal detection signal, again according to each detection signal priority of time of arrival, confirms the discharge source position of partial discharge of transformer, if A (x _a, y _a), B (x _b, y _b), C (x _c, y _c) being respectively the position of check point A, B, C, the coordinate of signal source to be positioned is M (x _m, y _m), can confirm that according to the travel-time of signal signal source is r to the distance of 3 of A, B, C ₁, r ₂, r ₃, system obtains by three frontier junctures:

$\sqrt{{(x_m-x_a)}^2+{(y_m-y_a)}^2}=r_1$

$\sqrt{{(x_m-x_b)}^2+{(y_m-y_b)}^2}=r_2$

$\sqrt{{(x_m-x_c)}^2+{(y_m-y_c)}^2}=r_3$

By above-mentioned formula can be in the hope of the coordinate of to be positioned some M:

$\left[\begin{array}{c}{x}_m\\ y_m\end{array}\right]={\left[\begin{array}{cc}2(x_a-x_c)& 2(y_a-y_c)\\ 2(x_b-x_c)& 2(y_b-y_c)\end{array}\right]}^{-1}\left[\begin{array}{c}{x}_a^2-x_c^2+y_a^2-y_c^2+r_3^2-r_1^2\\ x_b^2-x_c^2+y_b^2-y_c^2+r_3^2-r_2^2\end{array}\right].$

Technique effect of the present invention is: utilization of the present invention is arranged on the ultra high frequency discharge signal that the inner a plurality of discharge detectors of transformer detect transformer; Behind coding, deliver to processor processes; The priority that processor arrives according to each detection signal; Can accurately measure the discharge position of transformer, improve the bearing accuracy of Partial Discharge Sources, and guarantee the accuracy and the reliability of positioning result.

Below in conjunction with accompanying drawing the present invention is further described.

Description of drawings

Fig. 1 realizes that system of the present invention constitutes structural drawing.

Fig. 2 is a process flow diagram of the present invention.

Fig. 3 is a location algorithm schematic diagram of the present invention.

Embodiment

Referring to Fig. 1, Fig. 2, Fig. 1 is that the system of embodiment of the present invention constitutes synoptic diagram.System comprises a plurality of discharge detectors, information collecting center, signal conditioning circuit, the processor that is arranged on transformer inside.Fig. 2 is a process flow diagram of the present invention.Discharge detector is installed at transformer inner, and they are distributed in the diverse location place of oil tank of transformer as the reference mode of shelf depreciation location.When shelf depreciation in the oil tank of transformer produces the discharge steep-sided pulse, can excite simultaneously to produce the above uhf electromagnetic wave of hundreds of megahertz.Each discharge detector in the fuel tank can detect and receive ultrahigh frequency (UHF) signal that this discharge source produces, and directly receives the uhf electromagnetic wave of local discharge generation.Information collecting center is installed in the oil tank of transformer outside; Adopt optical fiber to connect discharge detector; Information collecting center form is according to the rules stored, is transmitted detection signal, and signal conditioning circuit carries out filtering, eliminates and disturb and noise signal detection signal, carries out calculation process by processor again; The sequencing that processor arrives according to each detection signal adopts TOA (Time of Arrive) algorithm that discharge source is positioned.

Fig. 3 is a location algorithm schematic diagram of the present invention.Three known check point A, B, C are arranged in the diagram, and the distance of M to three known node of unknown node is r ₁, r ₂, r ₃According to the relational expression on three limits, can be in the hope of the M point coordinate.

Described TOA location algorithm needs three position reference nodes at least, can realize accurate location, is a kind of important method in the triangulation location technique, and its positioning principle is:

The coordinate of supposing three known position reference nodes is: A (x _a, y _a), B (x _b, y _b), C (x _c, y _c), the coordinate of signal source to be positioned is M (x _m, y _m).Under the situation of known ultra-high frequency signal transfer rate, can confirm that according to the travel-time of signal signal source is r to the distance of 3 of A, B, C ₁, r ₂, r ₃System obtains by three frontier junctures:

$\sqrt{{(x_m-x_a)}^2+{(y_m-y_a)}^2}=r_1---\left(1\right)$

$\sqrt{{(x_m-x_b)}^2+{(y_m-y_b)}^2}=r_2---\left(2\right)$

$\sqrt{{(x_m-x_c)}^2+{(y_m-y_c)}^2}=r_3---\left(3\right)$

By formula (1) (2) (3) can be in the hope of the coordinate of to be positioned some M:

$\left[\begin{array}{c}{x}_m\\ y_m\end{array}\right]={\left[\begin{array}{cc}2(x_a-x_c)& 2(y_a-y_c)\\ 2(x_b-x_c)& 2(y_b-y_c)\end{array}\right]}^{-1}\left[\begin{array}{c}{x}_a^2-x_c^2+y_a^2-y_c^2+r_3^2-r_1^2\\ x_b^2-x_c^2+y_b^2-y_c^2+r_3^2-r_2^2\end{array}\right]---\left(4\right).$

The above only is a preferred implementation of the present invention, and under the situation that does not break away from ultimate principle of the present invention, modification of being made and retouching also are protection scope of the present invention.

Claims (1)

1. transformer partial discharge positioning method based on ultra high frequency detection technology may further comprise the steps:

Utilization is arranged on the ultra high frequency discharge signal that the inner a plurality of discharge detectors of transformer detect transformer;

The detection signal of discharge detector is delivered to information collecting center encodes;

Detection signal behind the coding is delivered to processor, and processor earlier carries out filtering, eliminates and disturb and noise signal detection signal, again according to each detection signal priority of time of arrival, confirms the discharge source position of partial discharge of transformer, if A (x _a, y _a), B (x _b, y _b), C (x _c, y _c) being respectively the position of check point A, B, C, the coordinate of signal source to be positioned is M (x _m, y _m), can confirm that according to the travel-time of signal signal source is r to the distance of 3 of A, B, C ₁, r ₂, r ₃, system obtains by three frontier junctures:

$\sqrt{{(x_m-x_a)}^2+{(y_m-y_a)}^2}=r_1---\left(1\right)$

$\sqrt{{(x_m-x_b)}^2+{(y_m-y_b)}^2}=r_2---\left(2\right)$

$\sqrt{{(x_m-x_c)}^2+{(y_m-y_c)}^2}=r_3---\left(3\right)$

By formula (1) (2) (3) can be in the hope of the coordinate of to be positioned some M:

$\left[\begin{array}{c}{x}_m\\ y_m\end{array}\right]={\left[\begin{array}{cc}2(x_a-x_c)& 2(y_a-y_c)\\ 2(x_b-x_c)& 2(y_b-y_c)\end{array}\right]}^{-1}\left[\begin{array}{c}{x}_a^2-x_c^2+y_a^2-y_c^2+r_3^2-r_1^2\\ x_b^2-x_c^2+y_b^2-y_c^2+r_3^2-r_2^2\end{array}\right]---\left(4\right).$

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