Planning Of Energy Storage System In Distribution Network Integrated With DG

Distributed generation is considered to be one of the important research directions of the electric power industry in twenty-first Century.Distributed generation will be applied in distribution network with large-scale access.The increase of permeability will bring a series of impacts on the distribution network voltage,power quality and operation.Energy storage can be a good solution to the problem caused by the increase of the permeability of the distributed generation.In this paper,the model of distribution network integrated with DG is established,and the method of distributed energy storage capacity and position optimization is studied.The main work is as follows:(1)This paper introduces the applied scenes of ESS,and models the distribution network integrated with DG,The models include DG,ESS,load and economic evaluation.The model of economic evaluation considerates life of elements.This chapter is the basic of ESS in distribution network integrated with DG.(2)This paper proposes a hybrid ESS capacity optimization method for optimizing the micro grid tie line power.Hybrid energy storage is more advantageous than a single one,which is more suitable for the optimization of the smooth output,the peak load and fill in the valley.The procedure of using genetic algorithm to solve the model is given.A case of a micro grid system in Tianjin eco city is used for verification,and the comparisons with the energy storage actually installed and the method of mainstream papers are made.The results show that achieving the same compensation effect,this paper delivers better economy.(3)This paper proposes ratio between energy storage and intermittent DG capacity with a practical storage capacity estimation method.The engineering philosophy of energy storage plan didn't makes out the ratio of energy storage and DG capacity clear.This paper makes out the relevant research based on the main research.This paper first introduces the calculation approach of ESS capacity based on filtering.Based on the experiment data,we analysis the relation of the biggest fluctuation and ESS rated power,the ESS rated power and ESS rated energy capacity,from which we can get the ESS capacity as soon as we get the biggest fluctuation and ESS capacity.Based on this,we can get the ratio by easy manual calculation instead of complex energy storage optimization method.(4)To accommodate the integration of DG,this paper proposes a bi-level optimization model to determine the optimal installation site and the optimal capacity of battery energy storage system(BESS)in distribution network.Based on the optimal scheduling of BESS,a novel capacity adjustment method is further proposed to achieve the optimal BESS capacity considering battery lifetime for minimizing the NPV of BESS.Finally,the proposed method is performed on a modified IEEE 33-bus system and proven to be more effective comparing with an existing method without BESS capacity adjustment.