Research On Simulation And Features Of SV Singular Points With Large Amplitude In Smart Substation

Traditional analog sampling has been replaced by digital sampling in smart substation, and therefore the relay protection has requirements for digital sampling of high reliability. With the full development of smart grid construction, abnormal SV points are increasingly becoming a threat to the power grid and an issue of great concern.There is still a lack of systematic classification and thoughtful studies of the mechanism for abnormal SV points in smart substation, characteristic parameters and test methods. This brings not only disputes to the engineers over the product design issues, but also difficulties to the formulation and evaluation of the test schemes. At present, the researches on algorithms which distinguish abnormal SV points only involve single point and sharp pulse. So the study on characteristic parameters of various SV singular points with large amplitude (flying points) has an important significance for improvement of protection algorithms.This thesis sums up the categories and mechanism of the abnormal SV points and refines out the intension on evaluation of the test schemes. The study focuses on characteristic parameters of the SV singular points with large amplitude (flying points). Based on the analysis of decimation, interpolation and filter system, the simplified conditions in the simulation are provided in this thesis, which reduce the uncertainty of simulation greatly. The definitions of characteristic parameters of the SV singular points are given for the first time. Especially the simulation method and key characteristic parameters of the SV singular points with large amplitude (flying points) are studied, which directly influences the protection algorithm. Using the MATLAB computing simulation capabilities, this thesis fully compares and quantitatively analyzes the variety typical situations of the singular points, which reveals how the characteristic parameters influence the typical protection algorithms and their inherent rules. At last, it brings out the test schemes for the abnormal SV points. This thesis provides a solution for evaluation of influence of abnormal SV points on relay protection, and the simulation system can serve as a valuable reference for improvement of protection algorithms.