Battery Energy Storage Systems for Low Voltage Network Management

With increasing concern for the security and environmental sustainability of the UK energy supply, the penetration of low carbon technologies on the grid has increased significantly. As the installed capacity of residential rooftop PV systems increases in the UK, the likelihood that LV networks will experience unacceptably high voltages and line utilizations increases also. Furthermore, an increased penetration of ASHP systems increases the likelihood of unacceptably low voltages and ampacity violations during winter periods.
Such network stresses are typically managed via reconductoring or redesign, but effective control of behind-the-meter BESSs may allow distribution network operator DNOs to delay traditional reinforcement. However, there is little consideration for the technical and economic barriers to BESS based violation management in current literature.
In this thesis, a series of mixed-integer quadratically constrained programming (MIQCP) formulations that determine optimal customer BESS takeover for violation control at various PV & ASHP penetrations are designed, a multi-period mixed integer linear programming (MILP) BESS placement and sizing model that optimally locates 3rd party owned BESSs systems is formulated, and a real time dispatch algorithm based on a 2-stage convex linear programming (LP) heuristic is developed.
These algorithms are applied to 6 networks located in the northwest of England to examine the technical feasibility of BESS control under varying PV penetrations, and BESS based control of ASHP demand on urban and suburban feeders is examined. The feasibility of BESS control for violation management in both the customer owned and DNO owned case are considered.
It is found that the costs associated with deploying behind-the-meter BESSs for the purpose of violation control greatly exceed those of reconductoring In the DNO-owned BESS case, and that significant technical barriers to the use of BESSs for violation control exist in the customer owned BESS case when violations are controlled using BESSs alone.