Regional Centralized Wide-area Backup Protection Algorithm

Along with the development of the Interconnection across the country and grid of UHVpower grid, the scale of the power grid of China is increasing, the structure of powersystem and operation control method is more complex, the grid suffered great threat to the safeand stable operation. Traditional relay protection depends on the specific value oftencannot guarantee absolute selectivity and cannot adapt to the modern power grid operationmode and changeable modern power grid; When a fault occurs, the large-scale flowtransfer caused malfunction, often cause widespread power outages. With wide-areameasurement technology and modern computer technology development, the wide-areaprotection as backup protection, has become a hot academic research, the future will be widelyused in actual power grid.In this paper, compare the advantages and disadvantages of integrated structure,distributed structure, substation centralized and regional centralized. The regional wide areabackup protection system structure of centralized communication information is little, easy toimplement, more in line with the modern power grid management habits, is the ideal model ofwide-area protection structure.The structure of modern large power grid structure is complex, and the zones division isone of the key technologies of regional centralized wide area backup protection needs to solve.The zones division method of wide-area backup protection system based on graph theory isdiscussed, discusses the main problems: the establishment of information domain, theselection of decision center station and the principle of partition interaction.Analyzes the properties of fault components, working principles of faultcomponent direction.The direction element is selected based on positive sequence faultcomponent due to the positive sequence component response to all types of short circuit fault,composite the positive sequence fault component current phase differential protection. Putforward the wide-area backup protection failure criterion, through simulation identifing thefault element. In view of the fault information loss affect the wide-area protection, a kind of multipleinformation fusion algorithm is proposed. Using the main protection action information, faultdirection information, the circuit breaker status of three groups of network information, toconstruct the fitness function based on genetic algorithm to describe the logical relationbetween these information to achieve fault recognition function. To correct the fault directionerror information in a certain range.