Research On The Coordinated Planning Of Distribution Network With Distributed Generation

Distribution Network is in the terminal of electric power system, which has a strong connection with customer. It is directly related to customers’power quality if the planning program of power system is reasonable. Distribution generation can bring customers convenience and environmental friendly energy, which makes the combination of the main network and distributed power supply to be the development trend of the smart grids.The continually access of distributed generation will have profound impact on the operation and planning of traditional power distribution network. Depending on the starting point, distributed generation planning can be broadly divided into two conditions:the siting and sizing planning of Distribution Generation in Distribution Network and expansion planning of Distribution Generation in Distribution Network. These two conditions respectively take the Generation expansion planning and the grid network planning as starting points. In this article, it studies and analyses the two conditions.The economic model of distribution network planning is built in this paper for the siting and sizing planning of DG. This model converts the minimization of the investment and operation cost and the circuit operating cost and takes that with the minimization of power purchase cost based on DG as objective function, build the normalized objective function by adding the node voltage constrains, wire current constrains, distributed power operation constrains that three inequality constrains through the punishment factor. Based on the outstanding performance of genetic algorithm in solving the problems like substation locating, constant volume and distribution network planning, this article used an improved adaptive genetic algorithm to solve the problem of siting and sizing planning of DG.Consider the new load nodes under the condition of distribution network expansion planning, determine the volume of DG according to new load nodes. Under the uncertainty circumstance of the amount, location and single power capacity, take the minimization of the investment and operation cost as objective function, first, use the improved adaptive genetic algorithm on DG planning, also use it in network expansion planning in terms of the capacity and individual location of every single step of DG.The impact of distributed power is jointed in and the feasible solution generated by the crossover and mutation operation genetic algorithm is repaired. Evaluate economic results according to the integrated planning to measure the merits of the individual programs.Calculation and analysis of practice showed that the algorithm in this article has improved in search capabilities and convergence performance compared to other genetic algorithms. Also the program about reasonable position and capacity of DG has been achieved. The simulation result showed that the introduction of DG has been benefit on the optimizing operation of the Distribution Network, in addition, it confirmed from the side that the DG technique has great beneficial effects after it was introduced into the power system, meanwhile it confirmed that the DG has vast application prospect.