Multi-Objective Allocation Of Distributed Generation Considering The Impact Of Relay Protection

Distributed generation(DG) is one of the important development direction of distribution network in the future. The operation mode and network structure of the traditional distribution network is changed by the access of DG, the higher requirements of distribution network design is put forward. The urgent need of distribution network construction and transformation is to realize the optimal allocation of DG, give full play to its advantages while reducing adverse effects on the distribution network. This paper focuses on the problem of optimal allocation of DG in distribution network, proposed multi-objective optimal allocation model of DG considering penetration of DG, system network loss improvement rate and voltage improvement rate.Firstly, the impact of DG on distribution network structure, power flow distribution, power quality, network loss, relay protection and network planning are analyzed. The research results show that the distribution network voltage level and network loss is closely related to the access location and access capacity of the DG, reasonable allocation is important to improve the permeability of DG and to play its advantage. For different types of DG, analyzed the grid structure and short-circuit current characteristics, put forward different models to solve the short-circuit calculation of distribution network with DG. Finally, the multi-objective function of the optimal allocation is established based on the DG penetration rate and the improvement rate of network loss and voltage, considering the effects of different types of DG on short-circuit current and relevant requirements of distribution network to establish the constraint conditions, the improved adaptive genetic algorithm was used to solve the optimization problem. Test results show that the proposed model can be used to obtain a reasonable allocation of DG, the DG permeability and the voltage and network loss of distribution network was improved, the transformation of the protection device was reduced, validity and feasibility of the proposed method are proved.