A test protocol to enable comparative evaluation of maximum power point trackers under both static and dynamic irradiance

The effectiveness of maximum power point trackers (MPPTs) is an important factor in the energy harvest economics of a PV system. Inverter manufacturers want to maximize the effectiveness of their MPPTs, and plant developers desire to choose inverters with the highest energy harvest to maximize their return on investment. However, comparing MPPTs against one another is challenging because the most common figure of merit, the MPPT efficiency, depends on the characteristics of the PV array and on the time variation of the irradiance. The commonly reported MPPT efficiency is essentially a static metric that does not translate well to performance under the wide range of real world conditions. To enable meaningful comparisons between MPPTs under both static and dynamic conditions, this paper proposes a standardized irradiance profile for use in determining MPPT efficiency. The proposed irradiance profile is designed to minimize bias in the results, maximize reproducibility, and be easy to use. The irradiance profile, its rationale, and its use are described herein.