Method for analyzing electric energy quality harmonic waves of digital substation

Abstract

The invention relates to the technical field of electric energy quality of digital substations of an electric system, and provides a method for analyzing electric energy quality harmonic waves of a digital substation. The method comprises the first step of receiving real-time sampling data x[n] sent by a merging unit (MU) of the digital substation, the second step of carrying out software digital filtering on the received real-time sampling data x[n] to filter out higher harmonic waves and disturbing signals to obtain the system frequency, the third step of acquiring the sampling rate of the digital substation and carrying out corresponding harmonic wave and inter-harmonic wave analyzing according to the acquired sampling rate to obtain the analyzing result, and the fourth step of carrying out subsequent index operation and interface display on the electricity energy quality according to the analyzing result in the third step and sending the electricity energy to a master electricity energy quality analyzing station. The method can meet calculation demands of harmonic waves and the inter-harmonic waves under various sampling rates, the calculation amount can be greatly reduced, and the actual engineering application demands can be met.

Description

technical field [0001] The invention relates to the technical field of electric energy quality of a digital substation in a power system, in particular to a harmonic analysis method for power quality based on a digital substation. Background technique [0002] With the development of digital substations, the practical application of new electronic transformers and intelligent circuit breakers, and the implementation of the DL / T860 standard, the communication network is gradually replacing the parallel cables at the interval layer and process layer of the substation, and has become the core of the protection and control system. An important part, the merging unit MU sends the collected data to the power quality monitoring device in the form of equal interval sampling, and the sampling rate is generally 4K, 8K, 12.8K, 51.2K, etc. However, since the frequency of the power grid is constantly fluctuating, and the power quality standard stipulates that the frequency tracking range...

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Problems solved by technology

[0005] (2) The invention does not specify the calculation method of interharmonics (decimal harmonics)

With the development of power quality monitoring technology, inter-harmonics have been paid more and more attention by the power industry, but this method only mentions integer harmonics, and does not mention the calculation method of inter-harmonics

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