Research And Implementation Of Phasor Measurement Algorithm And System

With the implementation of nation-wide power network interconnection strategies, the scale of the state grid of China expanded rapidly, the interconnection of the grid grow quickly. Improving real-time monitoring of the gird has become a critical problem that needs to be solved urgently. Traditional supervisory control and data acquisition system (SCADA) had the problems like low data sampling rate and common time base lackage in data acquisition, so it can not meet the demand of real-time monitoring of large regional power grid. Thus wide measurement system is presented to meet the needs of wide-area measurement and real-time monitoring.The domestic and foreign research on phasor measurement is analyzed in this paper briefly, and then different phasor measurement algorithms are studied and compared. As Kalman algorithm has the characteristics like simple module, needless of history data and some filtering functions, a ten-state Kalman filtering model based on linear Kalman filtering technique is proposed on the basis of previous work, the model is used to track voltage RMS, frequency, frequency changing rate, and initial phase angle of power system, which means to provide precise parameters for the system. The algorithm is derived using the second-order Taylor expansion formula, and then the formulas of parameters above are established. According to the signal model, time limitation is set to accelerate the response and the convergence speed of algorithm to signal mutation. A sample of the results obtained is reported in this paper through the simulated data, and we also compared the algorithm with recursive DFT algorithm.101communication protocol is an important protocol in power system and it is been deeply studied in this paper. According to the ideology of software stratification and system requirement, the implementation and division of module of supervisory control and data acquisition system is done on the basis of101communication protocol. C#programming language is used to package101communication protocol commands and data, data receiving and decoding and data storage are also completed. Finally, to meet the demands of client’s concurrent data uploading, data acquisition monitoring system frame format and hierarchical manner are used for reference; multi-thread technology is applied to accomplish the design of multi-thread communication server. The network setting of phasor measurement unit is presented in detail, and the frame format used in communication is also designed to work out the problem of pack sticking in TCP/IP communication. The phasor data received from measurement unit can provide data for other application software in the future.