Method for locating inter-strand short circuit fault point of transposed conductor and special locating device

Abstract

The invention provides a method for locating the inter-strand short circuit fault point of a transposed conductor. The method has the characteristics of capability of locating without puncturing a fault point, high locating accuracy and wide application range. The method comprises the following steps: applying certain impact high voltage between two inter-strand fault enameled wires of the transposed conductor to be tested by using a pulse high-voltage generator; puncturing the fault point to generate flashover discharge; placing a sound wave pickup probe of a sound wave detector above the transposed conductor to be tested, slowly moving the probe at a uniform speed along the transposed conductor to be tested and observing the swinging amplitude of a pointer while moving; when the swinging amplitude of the pointer becomes highest and is consistent with the frequency of discharge sound heard from an earphone; slowly moving the sound wave pickup probe leftwards and rightwards at the position, and distinguishing carefully to find a point with the highest discharge sound, namely, the located fault point. The invention further provides a special locating device, which comprises the pulse high-voltage generator, the sound wave detector, a sound wave receiver and the earphone.

Description

technical field [0001] The invention relates to the technical field of detection and testing of transposed conductors, in particular to a method for determining a short-circuit fault point between strands of transposed conductors and a special positioning device. Background technique [0002] At present, transposed wires have been widely used in the transformer industry. The latest transposed wire product standard JB / T 6758.1-2007 stipulates the requirements and methods for the DC voltage test of transposed wires, which stipulates that "in the transposed wire Adjacent enamelled flat wires should be subjected to a DC 500V voltage test, and there should be no breakdown during the test. When the breakdown current is greater than or equal to 20mA, the test equipment should indicate breakdown"; Adjacent to two enamelled flat wires, during the test, a 500V DC voltage is applied between one end of the transposed wire and the adjacent enameled flat wires for a period of not less tha...

AI Technical Summary

Problems solved by technology

Its disadvantage is that it needs to use 500V DC voltage to break through the short-circuit fault point between the strands of the transposition wire before detection, so that the short-circuit resistance between two adjacent enamelled flat wires can be detected before the fault point can be detected. The breakdown of two enamelled flat wires will cause the short-circuit fault point to be directly burned in a large area, resulting in a large damage surface (the insulation layer of the adjacent intact enameled flat wire is affected by the high temperature of the fault point and the insulation is damaged), which brings great harm to the repair. It is very inconvenient; if two adjacent enamelled flat wires between the strands do not break down, a virtual short circuit will be formed, resulting in a large resistance, and it is impossible to locate the short circuit point; in addition, the existing device is only suitable for short circuit resistance below 50 ohms, If the positioning error is within 10 meters, the positioning error will be very large if it exceeds this range

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