The Research Of The Multifunction Power Quality Monitor

Due to the power grid runs more and more load that is impact, rectifier typenonlinear and asymmetric, which makes the power quality problems areincreasingly serious. Such as voltage fluctuation, power harmonics, three-phaseimbalance and so on. At the same time it threatens the safety of power grid,especially the sophisticated electronics. Since the power quality caused seriousfinancial loss, it gets the attention of electric power department and users. So it issignificance to monitor the power quality.This text set out and analyze the development situation of domestic andoverseas, as well as six power quality national standard and explain implementmethod of the various parameters based on the Fast Fourier transform.Researching a double CPU multi-function power quality monitor which onaccount of DSP and ARM embeds the Linux system in ARM. It makes the mostof powerful data processing ability of DSP, the system control of ARM and therich peripheral interface. The basic CPU peripheral circuits are researched anddesigned: signal conditioning circuit, AD data acquisition circuit, thecommunication of DSP and ARM, and the communication of ARM and the hostcomputer, the LCD displaying, touch screen circuit and so on. Thus achievesvarious operational functions such as fast and accurate statistics, analysis, storage,communications, displaying etc of the power quality parameters, for example thesupply voltage frequency deviation, the grid frequency deviation, voltagefluctuations and flicker, and0-50harmonics and so on. It adopts reasonablehardware architecture, defines the division of labor of the monitor. That makesthe functions are more powerful. In this paper, the various computing algorithmsadopt the C programming language, and use software development tools Qtdesigner to design and implement friendly embedded interpersonal interface.Using the method of hardware and software co-design, adopting multi-threading mechanism to write applications to achieve control functions of ARM.In order to verify the feasibility of the various functions and if the accuracyreach design targets, using experimental comparison methods, and after analysisof the experimental data, the design requirements have achieved the nationalstandard.