Energy Management Approach to Battery Energy Storage in Unbalanced Distribution Networks

The integration of renewable energy sources (RESs) in active distribution networks (ADNs) offers numerous advantages, but it also introduces challenges such as voltage and frequency fluctuations, greater unpredictability due to RESs intermittency, and bidirectional power flow. To alleviate these undesired effects of RESs in ADNs, this work proposes energy management and optimal dispatch of battery energy storage systems (BESS). An energy management approach using optimal power flow in MATLAB as a mixed integer linear programming (MILP) problem and a rule-based method using load flow in OpenDSS is proposed to reduce the cost of operation and maintenance, losses, and voltage fluctuations in an unbalanced distribution network. Further, the BESS degradation and cycle life are considered for optimal dispatch and for determining the dispatch mode. The approach is tested on the IEEE 13-bus distribution network and a practical distribution network of a college campus. The scalability is tested using IEEE 123-bus distribution network. A comparative analysis of the results demonstrates the effectiveness in achieving the resulting benefits: operation cost saving, BESS cycle life improvement, voltage profile improvement, and loss minimization. The findings in this work highlight the potential of efficient operation of BESS to mitigate the challenges due to the proliferation of RESs in ADNs.