Capacity Expansion Planning with Respect to Reliability in Order to Transform an Existing Distribution Network into Micro-Grid

By growing the use of distributed generation (DG) in distribution power systems in order to improve the efficiency of this systems, constructing smaller grids (micro-grids) which can operate separately seems to be needed. This may have numerous benefits for consumers and distribution system owners such as easier control strategy, control among micro-grids, supplying demand using other micro-grids and improving the reliability of system. A supply-adequacy system can stop fault propagation and if the clustering procedure is designed properly, each part can act as a micro-grid with the least interaction with others. In this paper meeting load growth by installing DGs, maximizing reliability and minimizing total cost have been considered in planning stage. Clustering procedure is based on weighted graph partitioning method and the weights are apparent power of the lines. Because of the complex concept of reactive power and lower economic importance, it has been considered less than active power. So, in order to have accurate planning model reactive power is also addressed in this paper.