Impact of Distributed Generation on Power Flows Along Parallelly Operated MV Feeders

Medium voltage networks are usually operated in radial or open loop configuration. Temporary closed loop arrangement, used for load transferring without service interruption, is accompanied by the changes in power flows that result from the previous feeder loading and the difference in voltage phasors between supply substations. One of the potential operational problems is the insufficient interruption capability of sectionalizing switches to re-open the closed loop circuit. It depends on active and reactive power flows at the switch location. The simulation of interconnected primary feeders fed from different substations are performed to illustrate the impact of operational conditions, distributed generation of different capacities, different locations and different reactive power modes on active and reactive power flows, respectively current and its power factor in feeder sections. The interruption capability of common sectionalizing switches is assessed in order to show the potential operational constrains resulting from the requirement on safety reopening of closed loop circuit. Finally, the possible solutions to ensure the safety switching are discussed.