Evaluating dynamic maximum power point tracking with variable solar irradiance

Photovoltaic (PV) plant performance, among many factors, depends on inverter tracking of the maximum power point and its energy conversion efficiency. For a given PV array, under certain environmental conditions, the energy yield depends on the inverter´s dynamic response for maximum power point tracking (MPPT) with highly variable array output. This paper describes the theoretical irradiance test profile proposed in a European Norm Standard (EN 50530:2010) for inverter Dynamic MPPT efficiency evaluation. Example test results from two inverters are included. This paper also reports some discrepancy in the standard test profile by comparing the required test environment with high resolution measured solar irradiance ramp rate data for a South-East and a Western part of USA.