Optimal Allocation Of Distributed Generation And Its Effect On Power Quality

Because of its ability to use renewable energy, reduce environmental pollution,promote power quality, and retard upgrade and transformation of power system, muchattention is attached to the field of DG in the whole world. The combination of largegrid interconnection and DG can resolve the inconsistency of resources and load,enhance the stability of grid, promote system reliability, optimize the economy ofpower generation, transmission and distribution, and improve the system flexibility.Therefore, research on DG is full of significance. The paper mainly focused onoptimal allocation of distributed generation and its effect on power quality.This paper made an outline of the research status of DG planning, power qualityand renewable energy generation first, then introduced the DG technique, analyzedthe effect of DG on distribution network power quality, planning and reliability. Thepaper made a theoretical calculation of DG maximum capacity based on3typicalbuses of IEEE33-bus distribution system. Based on the target of maximum capacitypenetration of grid-connected DGs, an optimal allocation model of maximum capacityof grid-connected DGs in distribution network is established. Based on IEEE-33distribution system, an example is calculated through an improved PSO (ParticleSwarm Optimization) algorithm. Result proves that the model can reveal the truesituation, and algorithm is effective. Besides, this paper probes the problem of DGplanning without investment restriction and DG capacity restriction.On the basis of the model above, this paper establishes a DG planning modelfrom the view of economy. Optimization objective is the sum of DG investment, DGannual operation and maintenance costs, annual distribution network loss cost. Alsobased on standard IEEE-33distribution system, calculated by improved PSOalgorithm, a DG planning aiming at optimized economy is carried out. Compared withthe DG planning before, related conclusions are obtained. Finally, the paper analyzes the effects on power quality caused by DG from theview of DG types, capacity and locations. Based on the analysis, a power qualityassessment model applying AHP (Analytic Hierarchy Process) method in planningstage is established, a new power quality assessment method is posed. Based on thepower quality assessment model, the paper assesses three different DG planningschemes. Feasibility and effectiveness of the power quality assessment model areproved. The model can provide a reference for relevant engineering practice.