Load power matching MPPT for PV systems

Abstract Despite their common use, conventional MPPT algorithms, such as Perturb and Observe (P&O) and Incremental Conductance (INC), exhibit several limitations. These include oscillations around the MPP, delayed tracking response, and incorrect tracking direction when the system operates far from the true MPP. Such drawbacks arise primarily because these algorithms rely solely on instantaneous and previous measurements of PV voltage and power without using predictive information or reference values. This paper presents a novel MPPT control algorithm that utilizes a dynamic power-matching strategy based on the rated power of the electrical load perceived by the PV system. The proposed method enhances PV system performance by dynamically regulating the operation of the DC-DC converter such that the perceived load power matches the PV operating capability. When a mismatch is detected, the controller increases or decreases the perceived electrical load by controlling the DC-DC converter. The direction of the control action is determined by the deviation of the PV operating voltage from its nominal value. Hence, the proposed algorithm provides the controller with a reference-based framework at each sampling instant, avoiding dependence on the power-voltage slope, which becomes very small near the MPP. The simulation results show stable operation around MPP under varying irradiance and partial shading conditions.