MPPT solar charge controller for automotive industry

In this paper, a Maximum Power Point Tracking (MPPT) solar charge controller is designed and implemented to achieve the maximum power extraction from a photovoltaic (PV) panel during the charging of four Lithium Iron Phosphate (LiFEPO4) cells connected in series (4S1P configuration), which can replace the classical 12 V Lead-Acid battery of a vehicle. To maximize the power extracted from the PV panel, the MPPT controller uses a digitally-controlled synchronous DC-DC Buck converter through the Perturb-and-Observe (PO) algorithm, which sets the duty cycle accordingly. The main parameters of PV system (voltages, currents, powers for panel and battery) are measured and printed on the built-in Liquid Crystal Display (LCD) and are also transmitted over the Controller Area Network (CAN) interface to other Electronic Control Units (ECU) of the vehicle. Practical measurements are performed on a 100 W flexible PV panel installed on the roof of a vehicle and on Lead-Acid battery and a LiFePO4 battery pack installed in the luggage compartment.