Regulation of PV panel voltage using PI-P&O control algorithm

Abstract

The growing demand for the renewable energy resources, especially the solar energy, has drawn the interest of the researchers. The need for extraction of maximum energy has called for innovation of newer techniques so that the PV panel can be efficiently operated at its peak power under partial shading and dynamic atmospheric conditions. In this thesis, we have discussed the regulation of the output voltage of the PV array. We have observed the characteristics of the PV Panel under different temperatures and solar irradiations. Perturb and Observe Maximum power point tracking algorithm has been employed to operate the panel voltage at its MPP. Firstly, the panel peak voltage is obtained directly by varying the duty cycle of the converter. The direct duty Ratio control technique causes stress on the switch of the DC-DC converter besides loss of a significant amount of power. Therefore a PI controller has been implemented to regulate the panel voltage. A study using both DC-DC buck and boost converter as an interface between the PV Panel and the load has been presented. The PI controller prevents oscillation around the MPP apart from improving the steady state response and the settling time. A detailed analysis of the modeling of the PV array and DC-DC converters has been produced which helps in designing an efficient PI controller.