Modeling maximum power point tracking efficiency for PV systems

Photovoltaic (PV) system losses from inverter maximum power point tracking (MPPT) errors are a persistent source of uncertainty in PV performance modeling. MPPT efficiency comprises both static MPPT efficiency, which quantifies the array power captured under stable conditions, and dynamic MPPT efficiency, which applies under changing irradiance and temperature. Array-level I-V curve modeling can constrain both static and dynamic MPPT efficiency values for large-scale PV systems. We model static MPPT efficiency values as a function of the deviation in operating voltage from the maximum power point. We also estimate dynamic MPPT efficiency by introducing an MPPT time lag into performance models run for a variety of locations, time scales, and system designs. The results suggest that static and dynamic MPPT losses are likely minimal for modern inverters.