Research On Disturbance Detection And Location Method Based On The Data Of Synchronous Measurement System For Loads

With the continuous increase of the scale of the power grid and the application of a large number of power electronic equipment,the system presents the characteristics of power electronics.Its low immunity makes the risk of system disturbance increase constantly.The detection and positioning of disturbance can make the disturbance be targeted to reduce the impact of disturbance on the system.With the emergence and use of Synchronized Measurement Device for Loads(SMD-L),new conditions have been created for disturbance detection and location,and new research methods and directions have been provided for observing the disturbance information of the main network side by using the measurement information of the load side.In this paper,the load side data is taken as the research object,and the disturbance detection,disturbance propagation characteristics and disturbance location are studied in depth.Aiming at the problem of low accuracy of disturbance detection caused by many noises,bad data and large fluctuation of load side synchronous measurement data,the original data is reconstructed by ensemble empirical mode decomposition,and the noise in the data is removed under the condition of retaining the original trend of the data,so that the disturbance characteristics are more obvious,and the adaptive selection method of modal function is realized.The disturbance is further discriminated by combining the voltage amplitude,which reduces the influence of bad data on disturbance detection.Finally,the effectiveness of the proposed method is verified by the measured data and simulation data.Aiming at the problem that the spatial and temporal distribution of frequency dynamic response caused by disturbance makes it difficult to describe the characteristics of disturbance propagation,the influence of different power gaps and different disturbance occurrence locations on disturbance propagation is analyzed.By calculating the disturbance propagation velocity at the corresponding position of the measurement point,the disturbance propagation velocity of each point in the whole network is described.The disturbance propagation velocity characterization method suitable for different power gaps and different disturbance occurrence locations is further proposed,and the disturbance location error is used as an index to compare the accuracy of disturbance characterization in different situations.The rendering of the frequency in the process of disturbance propagation is realized,and the frequency changes in different regions during the disturbance process are visually displayed.Aiming at the problem that the frequency data fluctuates greatly and it is difficult to determine the accurate disturbance arrival time and the load side is difficult to obtain the system topology,the method of determining the disturbance arrival time by voltage mutation is realized by analyzing the frequency and voltage data before and after the disturbance.Further,the studied power grid is partitioned,and the arrival time of the disturbance of the measuring device in the region is compared according to certain rules to obtain the region containing the disturbance,and the method of quickly selecting the disturbance region is realized.Finally,the disturbance location equation is solved by using the regional boundary constraint,and the specific coordinates of the disturbance location in the region are realized.Finally,the effectiveness of the proposed method is verified by simulation and measured data.