Distribution Network Spare Capacity Unlocking Strategy to Integrate Heterogeneous Flexibilities

The increasing uptake of low-carbon technologies (LCTs) has brought heterogeneous flexibilities to the UK distribution network and poses significant challenges to distribution network operators (DNOs) to accommodate new flexible customers properly. This paper proposes a novel distribution network spare capacity unlocking (DNSCU) strategy for DNOs to integrate a group of customers with various flexibilities at certain nodes in distribution networks. Firstly, contingency analysis is implemented under N-1 criteria to quantify the additional allowable fixed load to the network. Then, the strategy is applied to unlock underutilized capacity in the network and determine the volume of extra allowable flexible customers. Finally, a multi-flexibilities connection model based on convex combination theory is established, which enables different customers with various flexibilities to share the same node. A 15-bus system is utilized to demonstrate the developed strategy. Consequently, more flexible demands can be introduced into the network, whilst guaranteeing network reliability for existing customers. The results exposit an increase in network utilization through the DNSCU strategy. This strategy provides an insightful view into network planning mechanisms given the fast-increasing requirements for flexible customer connections.