The new MPPT method for PV systems employing input characteristic impedance

This paper introduces a new Maximum Power Point Tracker (MPPT) technique for photovoltaic (PV) systems employing just a single voltage sensor. The MPPT algorithm is based on the variation of the input characteristic impedance of the basic DC-DC converter. Although the input impedance theoretically depends on its load resistance, it is shown that employing the proposed algorithm leads to the maximum available power without previous knowledge of its value. This technique can be applied to any DC-DC converter, mainly to the basic DC-DC converters as Buck, Boost, Buck-Boost, Cúk, SEPIC and Zeta. The validation of the proposed MPPT technique is given based on comparison between theoretical and experimental test results using the SEPIC DC-DC converter.