Two-stage PV power system with improved throughput and utility control capability

Abstract

For large, utility scale, PV systems a two-stage PV power conversion with distributed dc-dc conversion at the string level and a central inverter can provide significant improvement in PV generation in the face of mismatched panels and uneven irradiation (e.g. shading, clouds and soiling ). Such a system has been developed with funding under the U.S. Department of Energy SEGIS program. This paper investigates the performance of this system through modeling of various shading conditions and compares the results with measured performance from field testing of a prototype system. Improvements over a single-stage, central inverter of up to 46% for certain conditions are verified.