Mismatch Loss Optimization in PV Panel Arrays Using a Metaheuristic Approach

When two photovoltaic (PV) strings are connected in parallel to a single maximum power point tracker (MPPT) input, the tracker enforces one operating voltage on both strings, and whichever string is displaced from its own maximum power point contributes a power deficit. This loss is distinct from, and additive to, the mismatch loss arising among series-connected modules within each string. This work quantifies the two contributions separately and proposes a genetic algorithm (GA) that assigns modules from a real manufacturer flash list to strings and MPPT inputs so as to maximize the power delivered at the tracker, rather than the power of each string to be considered in isolation. Each module is represented by a double-diode model with parameters extracted from its flash list entry using a hybrid differential evolution procedure. String characteristics are obtained by summing module voltages at common current, and MPPT characteristics are obtained by summing string current at common voltage, so that the objective function evaluates the true interconnected operating point. For 68 modules of a 43.5 kW array, the mismatch loss is 0.398 W with separate MPPT inputs and 1.534 W with two strings per input. In the first case, sorting by MPP current lies within 0.122 W of the GA; in the second, all six criteria fall within 1.069 W of one another, random grouping ranks second, and the GA gains 3.243 W over the best of them. Sorting by a single parameter thus redistributes the loss between levels rather than removing it.