A method and device for state monitoring of power transformers based on fundamental wave zero-sequence characteristics

Abstract

The invention discloses a power transformer state monitoring method based on fundamental wave zero sequence characteristics. The method comprises the implementation steps that the fundamental wave zero sequence value of three-phase voltage and the fundamental wave zero sequence value of three-phase current of a monitored power transformer are acquired; fuzzy processing is performed through a fuzzy membership function set formed by N fuzzy membership functions to output a set of N fuzzy membership values so as to form the 1xN form of fuzzy state matrix P, wherein each fuzzy membership function is composed of a rectangular function and a triangle function section; and the degree of similarity of two sets of 1xN form of fuzzy state matrixes P and a preset standard state matrix S is calculated, and the standard state corresponding to the most similar standard state matrix is selected to act as the monitoring result of the monitored power transformer to be outputted. The disadvantages of the present transformer power outage verification and online verification method can be compensated so that judgment of the over-error fault of the transformer error can be conveniently and rapidly realized, and safe and stable operation of the power generation, transmission and distribution system and accurate and reliable high voltage electric energy trade settlement can be guaranteed.

Description

technical field [0001] The present invention relates to electric power engineering technology, in particular to a method and device for monitoring the state of a power transformer based on the zero-sequence characteristics of the fundamental wave, which is used to monitor the zero-sequence characteristics of the fundamental wave of the secondary signal of the three-phase transformer under any working condition. Identification, so as to realize the judgment of the state of the power transformer, and guide the operation management department to carry out condition maintenance in a timely manner. Background technique [0002] With the development of my country's economy, the power consumption has increased sharply, and the problems caused by high line loss have become increasingly prominent. According to the statistics of the State Grid Corporation of China, in 2014 the annual line loss rate of the State Grid reached 6.81%, and the power loss reached 250 billion kWh, a consider...

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Problems solved by technology

The traditional transformer calibration scheme needs to be implemented in a power outage. Due to the importance of the hub substation, this scheme is difficult to implement, so that faults such as transformer error out-of-tolerance cannot be detected in time, resulting in serious under-metering and seriously affecting the power grid. Economic Benefits of the Enterprise

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