Method Of Accommodating Load Based On Total Supply Capability In Distribution Network Planning

Traditional distribution system planning is suitable for fast developing areas,because adequate substation capacity is necessary to meet the fast increasing load demand. However, the load growth is slowly in developed areas with mature distribution network, and the focus of planning should turn to the optimization of existing networks. TSC(Total Supply Capability) theory takes the advantage in exploit the supply capability in existing distribution system. Based on the TSC theory,this paper proposed a method of accommodating load in distribution systems.Firstly, this paper proposed the method of accommodating power load based on TSC theory in distribution systems. The comparison between TSC theory and traditional distribution planning shows the TSC theory has higher priority in exploiting TSC from optimizing exist networks than to increase substation capacity.After 10 planning measures were summarized in 3 types with their priorities, this paper proposed the specific load accommodation process: 1) Collecting original data.2) Analyzing the power supply blind area. 3) Calculating the TSC. 4) Verifying the TSC and the total load. 5) Verifying the distributed TSC and feeder load. 6) N- 1verification. This method could assess the distribution system in a whole perspective,which provides guidance for a more accurate load accommodation.Secondly, for the key problem-verifying the distributed TSC and feeder load, this paper proposed a primary feeder load accommodation model, which taking the N-1security and load allocation into consideration and aiming to allocate all the loads to feeders in a proper feeder balance degree. This model was tested on a modified IEEE-bus4 distribution system and a real distribution system in China. The result includes the new load allocation and load transfer between feeders. However, the load transfer couldn't be operated as a result of the switches on feeders.Finally, a switches reconfiguration model was proposed for an operable load transfer between feeders. Based on the load transfer of the primary feeder load accommodation model, this reconfiguration model identified the switches needed to be reconfigured first, and then took the N-1 security as constraints and the status of the switches as variables to be solved by a genetic algorithm. Still, this model was tested on a modified IEEE-bus4 distribution system and a real distribution system inChina. The result achieved the load transfer between feeders. Thus, the complete and operable load accommodation method based on TSC for distribution system was formed.