Software Design And Implementation Of The Linux-Based Power Quality Analyzer

In industry production, the use of a large number of non-linear high-power loadscan cause power quality problems such as voltage disturbance, flickering, harmonicsand so on, which seriously interfere with the safety of industry production. Thinking ofthe growing problem of power quality and the increasingly demands for power qualityin high precision machines, it has important significance to research and designhigh-performance power quality monitoring machines to monitor and analyze the powerquality.The state-of-art in power quality analyzer is introduced in this thesis. On this basis,a design concept of power quality analyzer, a combination of power parametermeasurement, data display and storage and network communication, is proposed tomeet the demanding of high-precision, instantaneity and versatility. In which, themicroprocessor is dual-core OMAPL138, the core of the ARM-side software isembedded Linux operating system, and the core of the DSP-side software is DSP-BIOS.Firstly, the relevant parameters’ theoretical basis and detection method in powerquality, especially the principle of voltage sag measurement, are introduced according tothe measuring requirement in GB. Because of the traditional RMS detection method’sshortcoming that it cannot detect voltage sag and phase hopping, dq algorithm is chosento detect the voltage sag’s amplitude and phase. And an improved dq algorithm by usingderivation transform is proposed to reduce errors caused by dq algorithm’s delay.Secondly, the embedded Linux-based development progress and softwarearchitecture in design progress of ARM-side system software are described in detail,including the design pattern of multiple document interface, the transaction processingof multi-threaded data, the refresh algorithm of image display, the storage of powerquality parameter, the network transmission of electric parameters, and so on.Finally, the ARM-side system software and its relevant software function are testedand validated in the thesis. The result shows that the design pattern of multipledocuments and multi-line can speed up the program’s response time and the document size can be reduced and it’s not a problem for long-time record by using SQLitedatabase. Furthermore, compared with traditional serial communication and UDPcommunication, TCP communication has a higher speed and greater security. TheARM-side software in the thesis basically achieves the expected design purpose andneeds continuous improvement yet.