An Examination of Power Converter Architectures for Utility-Scale Hybrid Solar Photovoltaic and Battery Energy Storage Systems: The Features of Several Power Conversion Architectures

Abstract

Recently, the falling costs of photovoltaic (PV) and battery storage (BS) technologies have raised interest in the creation of hybrid PV+BS power plants. Together with increasing energy storage capacity by storing clipped energy, hybrid plants broaden a power plant’s grid services by featuring fast dispatch flexibility and voltage-ampere reactive support. Although many proposed PV plants are being developed with colocated batteries, the dominant architecture of ­utility-scale PV+BS power plants is uncertain. Moreover, power architectures are expected to evolve over time based on future trends. The primary goal of this article is to critically examine and compare several dc–dc and dc–ac power converter architectures that are suitable candidates for hybrid PV+BS power plants. In particular, the article presents characteristics of several power conversion architectures from the point of view of power semiconductor requirements, efficiency, reactive component requirements, modularity, control complexity, and so forth. Detailed analytical models are utilized, along with a benchmark design example to present a comparative evaluation of the alternatives for performing engineering tradeoff studies.