Distribution Network Planning With Micro-Grids

As an important part of Smart Grid, research on micro-grids is focusissue nowadays. Distribution network planning with micro-grids canrealize large-scale access of distributed generation(DG), decrease ofemissions of polluting gases and improvement of reliability of distributionnetwork. However, if the selection of DG in micro-grids is not suitable, orthe grid structure of distribution network is unreasonable, there will besome problems which are hard to solve for the operation of distributionnetwork. Thus, it is necessary to optimize type, site and capacity of DG inmicro-grids and to design the structure of distribution network withmicro-grids.Based on analyzing definition and characteristic of micro-grids, amodel of optimal site selection and capacity determination of DG inmicro-grids considering timing characteristic and environmental factor isestablished. Genetic algorithm is used to solve the model to optimize siteand capacity of DG in micro-grids and get an equivalent model ofmicro-grids according to the electrical characteristics relative to thedistribution network. Then, the distribution network planning withmicro-grids is researched: the substation planning model which usesminimum load moment as principle is established and multi-sourcecontinuous location method is adopted to solve it; the network planningmodel whose objective is to minimize the sum of line investment, networkloss cost and outage cost and constraints contain all network securityconstraints such as voltage constraints, line capacity constraints, powerflow constraints and reverse power flow constraints is established and genetic algorithm is adopted to solve it. At last, examples of optimal siteselection and capacity determination of DG in micro-grids and optimalstructure of distribution network with micro-grids are given to verify theeffectiveness and feasibility of the proposed model.