Variable-step incremental conductance (Inc.Cond.) technique, for photovoltaic (PV) maximum power point tracking, has merits of good tracking accuracy and fast convergence speed. Yet, it lacks simplicity in its implementation due to the mathematical division computations involved in its algorithm structure. Furthermore, the conventional variable step-size, based on the division of the PV module power change by the PV voltage change, encounters steadystate power oscillations and dynamic problems especially under sudden environmental changes. In this study, an enhancement is introduced to Inc.Cond. algorithm in order to entirely eliminate the division calculations involved in its structure. Hence, algorithm implementation complexity is minimised enabling the utilisation of low-cost microcontrollers to cut down system cost. Moreover, the required real processing time is reduced, thus sampling rate can be improved to fasten system response during sudden changes. Regarding the applied step-size, a modified variable-step size, which depends solely on PV power, is proposed. The latter achieves enhanced transient performance with minimal steady-state power oscillations around the MPP even under partial shading. For proposed technique's validation, simulation work is carried out and an experimental set up is implemented in which ARDUINO Uno board, based on low-cost Atmega328 microcontroller, is employed

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In this paper, a DC-link voltage sensorless control technique is proposed for single-phase two-stage grid-coupled photovoltaic (PV) converters. Matching conventional control techniques, the proposed scheme assigns the function of PV maximum power point tracking (MPPT) to the chopper stage. However, in the inverter stage, conventional techniques employ two control loops; outer DC-link voltage and inner grid current control loops. Diversely, the proposed technique employs only current control loop and mitigates the voltage control loop thus eliminating the DC-link high-voltage sensor. Hence, system cost and footprint are reduced and control complexity is minimized. Furthermore, removal of the DC-link voltage loop proportional-integral (PI) controller enhances system stability and improves its dynamic response during sudden environmental changes. System simulation is carried out and an experimental rig is implemented to validate the proposed technique effectiveness. In addition, the proposed technique is compared to the conventional one under varying irradiance conditions at different DC-link voltage levels, illustrating the enhanced capabilities of the proposed technique.

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