Research On Power Quality Algorithm And Its Host Computer Software

The power industry,as national fundamental industry,is closely related to social development and people's life.It provides energy for national economy.On the one hand,the continuous progress of science and technology provides technical support for the development of power system,and on the other hand,the using of many precision instruments and equipment increasingly highly demand for power quality.Any disturbance of power quality may cause serious economic losses to the electricity industry,and may even endanger personal safety.So it is very important to monitor the power quality.S transform algorithm and Kalman Filter algorithm are selected as tools to analyze power quality.The power quality monitoring platform is built based on the Web GIS,which can realize the display of real-time map,thermal chart,real-time database,and the index analysis.The main research contents of this paper are as follows:(1)This paper firstly introduces the research background,elaborates the current research status of power quality monitoring system at home and abroad,and then summarizes the power quality problem.The advantages and disadvantages of several common power quality algorithms are compared and analyzed,then determining using the S transform algorithm and Kalman algorithm to analyze the power quality quality.(2)An improved S transform is proposed,namely the fast discrete orthogonal S transform algorithm.The discrete orthogonal S transform algorithm is introduced,and the computational complexity of the algorithm is pointed out.In order to improve the efficiency of the algorithm,a fast discrete orthogonal S transform is realized by using matrix block technique and fast Fourier transform.The algorithm improves the computational efficiency and reduces the computational complexity.The computational complexity of FDOST is proved.The validity and practicability of the algorithm are verified through the analysis of the simulation data and the actual fault recording data.(3)Aiming at the shortcoming that the Kalman algorithm can not deal with the nonlinear problem,this paper realizes the unscented Kalman filter algorithm with Unscented Transformation.The non-linear state space model is established according to the input voltage signal,and then the unscented Kalman filter(UKF)is used to estimate the fundamental component,DC component and fundamental frequency based on the nonlinear model of the signal.Through the analysis of several sets of simulation data,it shows that the unscented Kalman filter algorithm has good anti-noise ability.Meanwhile,the simulation results show that the algorithm is adaptive to the sudden changes of frequency,DC offset component and fundamental amplitude.(4)The key technology of the basic energy quality monitoring system is introduced,including Web GIS,Baidu map API,Ajax local refresh technology and Socket communication technology.The real-time data received by each monitoring station is stored in SQL Server 2005 database through Socket communication technology.A power quality monitoring system of Web GIS is designed based on Microsoft Studio 2010 platform,using ASP.NET technology and Baidu map API.This system includes the display of real-time map,thermal chart and real-time database.Besides,querying historical data,index analysis and site addition are also involved.