Research & Improvement Of Electric Parameter Monitoring Device And Algorithms

This thesis develops this electric parameter monitoring device that is based on MSP430F149. This device is the research and improvement production on the base of the primary device. This device may perform real-time measuring of frequency, effective value of voltage and current, power, from the third to fifteenth harmonic wave, etc. It may also realize key-press controlling, LCD displaying and communicating. After completing designing and debugging the device, the following conclusions are drawn:Firstly, the factors that cause the synchronous errors by the normal software synchronization sampling is analysed, through emulative analyzing and comparing several easily realized algorithms, cumulated deviation increment sampling is chosen to adopt in this device.Secondly, the influence that caused by window effect, including frequency resolution, leakage effect and resume coefficient of the window function are discussed. Aimed at leakage effect, a new kind of combined window contrasted by windows based on cosine is advanced. Through emulative analyzing, it validated that this kind of combined window could restrain the leakage errors effectively.Thirdly, the data processing cell, display and key-press cell, communicating cell of the device are introduced in detail. According to MSP430F149's characteristics, the anti-interference measures that the device adopts are discussed.Lastly, measure precision of the parameters are analysed, accuracy of these parameters are provided, the hardware and software factors that affect the measuring accuracy of the device are discussesd and gives the corresponding improving measures.