Development and evaluation of an improved operation algorithm for a Li-Ion battery energy management system at Tezpur University, India

Abstract: In response to the ever-increasing threat of the negative impacts of climate change, there has been a renewed international focus on the integration of renewable energy to meet their demands. One such project is located at Tezpur University in the state of Assam, India. In this project, a large PV project of 1 MWp capacity was installed in 2018, followed by a 91 kWh Li-ion battery system in 2020. While the system has been installed, an optimal operational algorithm (OA) is needed for the system to operate and meet the needs of the connected load. This thesis will consider several OAs for the battery system. The charging schedule for the system will be optimised based on data for the substation system. First, data from the electrical load and power outages with a time resolution of one minute were considered. Upon analysis of this data, an initial algorithm was proposed and its effectiveness was evaluated based on selected key performance indicators (KPIs). Next, a linear programming approach was used to optimise the battery charging schedule based on electricity cost, PV power production, and electric load. Based on the results of the optimisation, input from the proprietors of the energy management system, and results from the initial algorithm, a second advanced algorithm was created and its effectiveness was again evaluated based on the same KPIs. It was found that the two main goals within this project, initiating appropriate charging times to limit grid power usage while also maintaining sufficient energy reserves whenever a power outage occurs. While diesel usage cannot be completely eliminated, it can be greatly reduced for shorter power outages. Additionally, a high degree of load autonomy can be achieved before the diesel generator becomes necessary to activate.