Two-phase Optimal Planning Of Substation Locating Based On Refined PSO Algorithm

Substation locating is very important in grid planning. It's significant for the function of power system and its efficiency to determine the capacity,locating and power supply bound of substations scientifically. How to decide the location of new substations and optimize the connection between new sites and the former ones means a lot for power grid planning.This paper compares advantages and disadvantages of various methods applied home and abroad in substation locating, analyzes the algorithm of refined PSO and fuzzy analysis hierarchy at length, builds the mathematic model of substation locating and proposes a two-phase analyze method of substation using the algorithm of refined PSO with extremum disturbed operator. A example of substation locating in some economic developing area is analyzed with this method.The article calculate the number and capacity of patulous substations and new ones according to scale of load in planned year, the location and capacity of foregone substations as well. Considering the principle of balancing load factor and supplying the power handily, this method divides the power supply area, turning the multiple target substation locating into single one. The latter includes two phases: Firstly, use the refined PSO to search the best location in divisiory area and get the first-candidate locations; secondly, check if the first candidate location is feasible geographically or not. If it's not doable, adjust this one and choose some second-candidate location in nearby area and form several combinations with other feasible locations. The method evaluates the influence of geographic factors in quantity using fuzzy analysis hierarchy and gains the geographic factor in target function, calculate the difference of target function cost because of difference of grid structure and geographic factors in various combinations. The combination with the lowest cost is the final one. This paper refines the target function, considers the cost of input and output lines of substations to make the planned result more external and reasonable. The example shows that this method raised could better satisfy the planning demand.