Acquisition And Analysis Of Transient Power Quality Disturbances

It is concerned for researchers that improving and enhancing the power quality toensure the power system operate sately and economicly have become widespread.With increasing number of power quality problems, such as a variety of non-linear,impact resistance and volatility load, power electronic system becomes serious and itis growing. Therefore, building a theoretical framework and doing intelligentanalysis for transient disturbances in power quality problem, not only accuratelycapture and identify ideas and methods to solve transient power quality disturbance,can also provide intelligent management and governance of the power qualitydecision-making and basis. That analysis and collection wih transient power qualitydisturbance of power quality problems are needed to be solved.(1) Background and significance of the research is elaborated. By studying a largenumber of literatures, we summarized data collection and analysis methodsto transient power quality disturbance at home and abroad.(2) The acquisition system of transient power quality disturbance is built. Basedon this, we advance a set of collection system design of hardware block diagram, butwe are focusing on the accuracy of acquisition system constituted from sensordetection, the signal conditioning circuit and ADC three modules at here. At the sametime, we analyze clock jitter which affect the system samping precision.It provides astrong theoretical basis to improve the performance of system and the increase ofADC sampling accuracy in the way of expounding the characteristics and methods tomeasure.(3) We elaborate the traditional methods of non-stationary signal processing withnon-stationary characteristics with transient power quality disturbances signal.Focusing on the analysis of Fourier transform, Short Time Fourior transform andWavelet transform, we point out the respective applicable condition and scope ofapplication, and put forward Hilbert huang transform approach to carry on theanalysis of non-stationary signal processing. We make more detailed analysis of theconception of intrinsic mode function, empirical mode decomposition, Hilbertspectrum methods, etc. Then, we summarize Hilbert huang transform approach withtemporal clustering and strongad aptability.(4) Hilbert huang transform method is used to analyze transient transient power quality disturbances by MATLAB software simulation tools, which can accuratelyverify its accuracy and effectiveness. Firstly, by compareing analysis results of thesame non-stable signal among Hilbert huang transform, Fourier transform and Hilberttransform, the effectiveness of Hilbert huang transform in the analysis for powerquality disturbance signal is verifed. Then, Hilbert huang transform is used tosimulate the single and multiple disturbances in the transient disturbance. Simulationfigure identifies basic types of disturbances, form data counts the ideal and the realstart and end time, amplitude, frequency and other parameters of disturbance signal,the effectiveness and practicality of Hilbert huang transform in the analysis oftransient power quality disturbances are verified by calculating the form data.