Microcontroller based step-up DC-DC converter driver with MPPT algorithm implemenation

Energy efficiency is one of most critical parameters in photovoltaic (PV) systems. Overall PV system efficiency improvement may be achieved by such means as topological changes, new generations of transistor switches and/or planar magnetic components use. But on the other hand whole system must follow the wheather changes such as solar energy delivery variation due to cloud shading as well as temperature fluctuations. In such conditions a driver should dynamically track maximum power point (MPPT) of a PV array. For the purposes of better understanding PV array performance the paper shows MatLab simulation of 3.2 kWp PV array. The driver discussed works with a range of different step up DC-DC converter topologies such as bridge based topologies as well as interleaved ones. The ASCII protocol which can be implemented in PC application is responsible for working parameters settings carrying and output data logging as well as current software status check. The paper presents practical implementation of the driver as a part of larger PV system where the interleaved DC-DC converter works with 3.2 kWp PV array of ten PV modules connected in parallel. Described MPPT algorithm takes advantage of modified Perturb and Observe (P&O) method. Presented are microcontroller hardware resources utilization, functional software architecture and developped MPPT algorithm which performance is shown on the plot.