Application of the Maximum Power Point Tracking (MPPT) Algorithm on Lithium-Ion Batteries

Abstract

This work focuses on the application of the maximum power point tracking (MPPT) algorithm to discharge lithium-ion batteries at their maximum possible power. This algorithm is routinely applied in photovoltaic applications but has only seen limited application in battery applications so far. A simple form of the MPPT algorithm is used in this work. A fixed magnitude of current is applied, and the new value of power is calculated. If the new value of power is greater than the previous one, the current is varied in the same direction until the maximum power is reached. This algorithm is simple to implement and consumes low computing power. However, the magnitude of a current step should be optimized. If the current step is very small, the time taken to reach the maximum power will be too long. And if the current step is very large, there will be a large oscillation near the power maxima. Therefore, we study the effect of current steps during application of the MPPT algorithm on lithium-ion batteries. Comparative studies between various optimization methods such as gradient descent, steepest descent and Newton’s method are made. The effect of discharging batteries at their maximum power on their life cycle is also investigated. The information obtained from this study can be a useful guide to designing a battery management system that gets the maximum performance out of a lithium-ion battery. References Selvan, P. Nair and Umayal, “A review of photovoltaic MPPT algorithms,” International Journal of Electrical and Computer Engineering, 6, 2016, 567-582.A. B. Vieira and A. M. Mota, “Maximum power point tracker applied in batteries charging with PV panels,” 2008 IEEE International Symposium on Industrial Electronics, Cambridge, 2008, 202-207.Kim, S. Mohan, J. B. Siegal and A. G. Stefanopoulou, “Maximum power estimation of lithium-ion batteries accounting for thermal and electrical constraints,” Proceedings of the ASME 2013 Dynamic Systems and Control Conference, California, 2013.