New Planning Principles for Distribution Networks with Penetration of Distributed Energy Resources

Power systems are experiencing an increased uptake of distributed energy resources (DERs) such as photovoltaic (PV), wind power, battery energy storage systems (BESS) and electric vehicles (EVs). While DER penetration has several benefits, it can also result in some technical issues. The most reported issues include voltage-rise, voltage-drop, unbalance, and the thermal loading of conductors and transformers. For these issues, the severity depends on the conditions and level of penetration. As a result, current research focusses on deriving limits for penetration for regulation on existing networks. For new electrification systems, the uptake of DERs demands new planning principles such that the sizing and selection of network equipment, such as feeder cables and transformers, consider scenarios of DER uptake. Furthermore, the uncertainty associated with the operation of such networks, particularly the location and capacity of DERs, must be considered. This paper discusses the requirements for probabilistic network planning, considering DER penetration. Results from comparative studies of selected approaches show the inadequacy of traditional planning methods and demonstrate the need to include the uncertainty of future DER installations, else the designed systems are prone to be noncompliant under various penetration scenarios in the future.