A Direct Current MPPT Control with Eliminated Outer Loop For Grid Interfaced Solar Inverter

The maximum power extraction of solar PV panels is influenced by not only solar irradiance but also climatic conditions like ambient temperature, humidity, and cloud cover. Thus to extract the maximum power from the solar PV array irrespective of dynamic climatic conditions, the MPP algorithm is an essential need of grid-connected inverters for efficient energy harvesting. Nevertheless, various maximum power point tracking algorithms are available based on the voltage reference generation corresponding to maximum power. Since the solar panels primarily exhibit the current source characteristics and the inverter operates in current injection mode, the current reference generation instead of voltage reference can eliminate the outer voltage loop of the grid-connected inverter. It makes the control loop more robust and efficient in MPP tracking. Considering this fact, in this work, a novel Current MPPT technique for PV energy extraction is proposed. The proposed algorithm generates the current reference for the inverter corresponding to available active power from the sensed PV voltage and current. The superiority of the proposed algorithm in terms of maximum power tracking compared to the conventional MPPT technique is demonstrated through MATLAB simulations.