A hybrid MPPT technique based on the fast estimate of the Maximum Power voltages in PV applications

In PV applications, under mismatching conditions, the adoption of a Maximum Power Point Tracking (MPPT) technique which is able to regulate not only the voltages of the PV modules of the array, but also the DC input voltage of the inverter is necessary in order to inject into the grid the maximum available energy. Such a technique can be considered an Hybrid MPPT (HMPPT) technique which is neither only distributed on the PV modules of the PV array or only centralized at the input of the inverter. In this paper a new HMPPT technique is presented and discussed. Its main advantages are the high MPPT efficiency and the high speed of tracking obtained by means of a fast estimate of the maximum power voltages of the PV modules and of the inverter. The new HMPPT technique is compared with a HMPPT technique based on the coupled adoption of the Perturb & Observe technique, distributed on the PV modules, and of a suitable centralized MPPT technique carried out by the controller of the central inverter and based on the periodic scan of the power versus voltage characteristic at the input of the inverter.