Digital Flicker Detector Based On Dual-core Structure

With the development of Chinese economy, it appears that a lot of power into the grid load changes, causing power grids voltage fluctuations and flicker, power quality decline, so the other devices in the power network are affected. Therefore, flicker measurement becomes an important issue which people pay attention. However, most of the flicker detector designed in China based on industrial PC add data acquisition card or based on the virtual instrument technology plus data acquisition device structure design way, as they are very expensive or hard to carry in using field. This paper proposes a kind of digital portable flicker detector based on the ARM + DSP dual-core structure, the flicker detector uses ARM as the main controller, uses digital signal processor (DSP) for sampling and processing data, and its characteristic are compact, easy to operate, friendly interface, cost low.This paper mainly expounds on the following:(1) Flicker concept and IEC measurement methods outlined. Describes the voltage fluctuation and flicker related concepts, and introduces briefly the flicker detection methods which are recommended by the international electrician commission IEC.(2) Detection methods selection. According to the comparisons of the common flicker detection methods'advantages or disadvantages, and our country's GB 12326-2000 voltage fluctuation and flicker national standards and design requirements, chooses IEC flicker detection methods as flicker detection method and improves detection wave link.(3) IEC digital detection methods. IEC flicker detection methods are descript by S domain transfer function, while flicker detector using the all-digital design. In order to solve this problem, according to the comparisons of the digital methods'advantages and disadvantages, chooses bilinear transformation method to make the IEC flicker detection method S domain transfer function digitally.(4) Proposing the second sampling algorithms. Flicker measurements cost long time, and in order to ensure measuring accuracy of flicker instrument, requires a higher sampling frequency, this would appear the problem that the dealing-datas size is very large. So the real-time of flicker measurements process has some difficulties, and the embedded system hardware resources requires a high demand. In order to solove the problem, this paper gives the sampling algorithms to compress treat processing data. Correctness of second sampling algorithms are tested by MATLAB tools.(5) Software and hardware's design and testing. All of this design of digital flicker meter software and hardware system is comprehensively introduced, including hardware framework, selection of hardware modules main parts and circuit design, general structure of software system ,measuring software and other software modules'design.Finally, summarizes the results of the all-digital flicker detector design which based on the dual-core structure, it also shows the deficiency of all-digital flicker detector and the target of function's improvement.