Calculation method of transformer harmonic loss based on frequency conversion property

Abstract

The invention provides a calculation method of transformer harmonic loss based on a frequency conversion property. The calculation method is characterized by comprising a direct-current resistance loss of a transformer winding under a non-linear loading condition and other stray losses of the transformer winding under the non-linear loading condition, calculating an eddy-current loss correction factor of the transformer winding, modeling the transformer by the transformer harmonic loss based on the frequency conversion property and the like, and calculating and analyzing the harmonic loss. The method provided by the invention has the advantage of accuracy of loss calculation of the transformer under the non-linear loading condition; compared with the traditional harmonic calculation method, on the basis of analyzing the frequency conversion property of a winding model, the harmonic loss is corrected by considering an overlapping calculation of an equivalent non-linear parameter of each subharmonic lower winding and the harmonic loss; therefore, the calculation method has the advantages of stronger adaptability and higher actual application value.

Description

technical field [0001] The invention is a transformer harmonic loss calculation method based on frequency-varying characteristics, which is applied to transformer accurate loss calculation, economic operation analysis and optimal capacity configuration. Background technique [0002] The operation status of the transformer directly affects the safety and stability of the power system, and the impact of its loss on economic operation cannot be ignored. According to the survey, the loss of transformers in the national power grid accounts for about 3% of the total power generation, and the loss of distribution transformers accounts for about 60% to 80% of the loss of the entire distribution network. In recent years, a large number of non-linear loads such as frequency conversion electrical appliances and devices have become more and more common in industry and life, resulting in a sharp increase in power grid energy consumption, and at the same time causing adverse effects such ...

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Problems solved by technology

[0003] On the one hand, the traditional transformer loss calculation obtains the measured data through a large number of experiments, and uses the curve fitting method to obtain the change curve of the equivalent parameters of the transformer under each harmonic, and calculates the harmonic loss through the superposition principle, without considering the saturation of the core On the other hand, the harmonic loss is calculated through experimental measurement and operating experience data, but the calculation of DC resistance loss is relatively rough, the distribution of eddy current and stray loss is not applicable, and the calculation of harmonic loss is conservative

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