With renewable energy based electrical systems becoming more prevalent in homes across the globe, microgrids are becoming widespread and could pave the way for future energy distribution. Accurate and economical sizing of a standalone power system components has been an active area of research, but current control methods do not make them economically feasible. Typically, batteries are treated as a black box that does not account for their internal states in current microgrid simulation and control algorithms.¹ This might lead to under-utilization and over-stacking of batteries. In contrast, detailed physics-based battery models, accounting for internal states, can save a significant amount of energy and cost, utilizing batteries with maximized life and usability.² However, typical microgrid controls including feedback algorithms cause a significant time-delay as detailed physics-based battery models are coupled to the entire microgrid system.³ It is important to identify how efficient physics-based models of batteries can be included and addressed in current grid control strategies.

In this talk, we will show that perhaps the best way to integrate detailed battery models is to write the microgrid equations in mathematical form and then identify an efficient way to solve those models simultaneously with battery models, which gives better results. Implementation of the maximum power point tracking controller algorithm and physics-based battery model along with microgrid components as differential algebraic equations will be discussed. The results of the proposed approach will be compared with the conventional control strategies and improvements in performance and speed will be reported.

Acknowledgements

This work was supported by the Clean Energy Institute located in University of Washington, Seattle and Washington Research Foundation.

References

1. D. A. Beck, J. M. Carothers, V. R. Subramanian, and J. Pfaendtner, AIChE Journal, 62(5), 1402-1416 (2016).

2. M. T. Lawder, B. Suthar, P. W. Northrop, S. De, C. M. Hoff, O. Leitermann, M. L. Crow, S. Santhanagopalan, and V. R. Subramanian, Proceedings of the IEEE, 102(6), 1014-1030 (2014).

3. B. Subudhi and R. Pradhan, IEEE Transactions on Sustainable Energy, 4(1), 89-98 (2013).