Research On Power Quality Analyzers Based On HHT

With the development and growth of grid scale, the problem of power quality isincreasingly serious. Only by effectively monitoring various kinds of power qualityproblems can be targeted on improving and governing. Power quality analyzers areessential analytic tools. Traditional mathematical analytic methods can’t effectivelyrecognize some power quality problems, especially transient phenomena, andintelligent construction of power grid puts forward higher requirements on terminalequipments, so it is necessary to explore and research power quality analyzer’sanalytic algorithms and design plans. Power quality analyzer is one of the monitoringinstruments, algorithm is its core, and framework is its support. Around these twothemes, this paper launches a series of exploration, research and practice work, whichincludes theory research, plan design and experiment validation three aspects.Some analytic methods commonly used in power quality analysis were analyzedand summaried, aimed at the existed shortcomings of above methods, a designconcept based on Hilbert-Huang Transform (HHT) algorithm was proposed, andEmpirical Mode Decomposition (EMD) method and some HHT’s key points such asendpoint processing, termination conditions were studied, meanwhile, the feasibilitythat HHT applied to power quality was explored.DSP+ARM+embedded Linux design solutions were put forward, according to therequirements of smart grid construction and information age development. In themeanwhile hardware circuit was designed and software framework was constructed.Algorithms were implemented on the basis of hardware platform. Accuracy test,signals recognition experiments were verified, and harmonics of an aluminum plantwere analyzed, the analysis result was compared with the result of Fluke430powerquality analyzer.The result shows that HHT method can effectively identify transient signals,inter-harmonics and some power quality phenomena. HHIT is a self-adaption methodwith higher time-freqency analysis performance and high precision. DSP+ARM+embedded Linux design solution embodies current mainstreamtechnology and design concept, it can greatly improve the intelligent level of powerquality analyzer. This research contributes to advance the progress of power qualityanalysis methods, promotes the level of intelligence of product and improves theadministration of power quality problems.