A Method for Measuring DC Resistance of Large Power Transformer at Super Speed

Abstract

The invention discloses a method for over-speed measurement of direct-current resistance of a large power transformer. The method comprises the following steps: establishing a test loop including a constant flow source inside a direct-current resistance tester, a standard resistor in the constant flow source and a winding of the transformer by adopting a total pressure constant flow source method; fluctuating the constant flow source by current at a certain amplitude nearby a preset output current until an output current of the constant flow source is stabilized with a certain current value; and obtaining a resistance value of the transformer direct-current resistance by adopting a direct-current voltage on the transformer winding, a voltage on the standard resistor and a resistance value of the standard resistor. The method disclosed by the invention can be used for achieving purposes of over-speed measurement and accurate measurement. Compared with a current rapid tester, under same testing current and wiring mode, the method can be used for controlling consumed time within merely 1 / 10; and the method disclosed by the invention has the significance for shortening power failure time of equipment, reducing labor intensity, prolonging service life of the transformer and enhancing stability of a power system.

Description

technical field [0001] The invention relates to the technical field of electronic circuits, in particular to the technical field of transformer detection, in particular to a method for measuring the DC resistance of a large-scale power transformer at high speed. Background technique [0002] Power transformer DC resistance measurement is one of the test items that must be done in the factory, handover and preventive tests. The correctness of the branch circuit, whether there is one or several disconnections in the winding wound by several parallel wires, check whether there is a short circuit between layers and turns. [0003] We know that to measure the DC resistance of a transformer, it is to regard the transformer winding as a circuit in series with a larger inductance and a smaller resistor, and pass a direct current into the circuit. When the direct current is stabilized, the inductance of the larger inductance decreases to When it is close to zero, measure the DC volt...

AI Technical Summary

Problems solved by technology

[0016] In view of the above-mentioned shortcomings of the prior art, the purpose of the present invention is to provide a method for over-speed measurement of the DC resistance of a large power transformer, which is used to solve the technical problem of measuring the DC resistance of the transformer for a long time in the prior art

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