277 results about "Fuzzy mathematics" patented technology

The invention relates to a small current grounding route selection system, in particular to the improvement of a grounding fault route judgment method, which belongs to the technical field of electric power engineering. The method comprises the following steps: 1) setting the sampling data window time of measuring variables 3U0 and 3I0, collecting n measuring variables, and carrying out gross error removal on each measuring variable; 2) organically combines a group amplitude comparison and phase comparison method and a watt component method, and utilizing a fuzzy mathematical tool for setting membership grade functions for two criteria, substituting route selection results obtained by the two methods into the membership grade functions to obtain the membership grade of the route selection results, i.e. the credibility, wherein the route selection result with the highest membership grade is the composite route selection result, and the second highest membership grade is used as the reference; 3) organically carrying out trial jump on the route selection of a fault route switch for reaching the effect that the operation is more safe and reliable, and the fault positioning is more accurate; and 4) carrying out route selection again every ten minutes for preventing the grounding route conversion. Grounding time, routs (sequentially ranged from the large possibility to the small possibility) with large grounding possibility and 3U0 and 3I0 values of all outlet wires on a bus line section with the occurrence of small current grounding are displayed in an information frame.