Photovoltaic Module Maximum-Power-Point Tracking with Step-Size Variation

In order to maximize the output power of a photovoltaic (PV) module, a power converter is normally used for moving the module operating point towards the maximum power point (MPP). This paper presents the PV power maximizing approach based on the incremental conductance technique with adaptive step-size procedure. An increment in switch duty cycle of the converter is directly derived from a desired increment in the module voltage, which is relative to the location between the operating point and the MPP. The performance of the proposed method and that of the fixed step-size scheme are compared under rapid fluctuations in weather conditions.