Mission profile characterization of PV systems for the specification of power converter design requirements

摘要

This paper presents a comprehensive methodology to characterize the mission profile of photovoltaic systems, through which a powerful set of relevant information may be obtained and used in order to improve the design of power converters. Characterizing a photovoltaic system accurately is not trivial and this paper aims to present a detailed methodology on how to obtain a PV real field mission profile. Three cities with different climate were considered and a large dataset of four variables was used: global horizontal, direct, and diffuse irradiances and ambient temperature. Data were measured at one-minute intervals over multiple years. For each location, four scenarios of panel orientation were analyzed: horizontal position, fixed tilt, 1-axis and 2-axis mechanical tracker. A mathematical model to estimate instantaneous in-plane irradiance based on measured data and mounting type was used. An average profile of solar energy and ambient temperature for each city were bui these profiles were used as input for estimation of annual energy yield of a commercial photovoltaic panel, which was mathematically modeled and validated. Current and power processing throughout a year in a one-minute resolution were investigated, along with the most frequent and most significant operating points in each scenario. Panel operating temperature related to ambient conditions and its relation to energy yield were also studied. Finally, a comprehensive discussion to understand how different mission profiles affect power processing of photovoltaic power converters and the way this characterization can aid in pre-sizing and lifetime analysis of power electronics is presented. (C) 2017 Elsevier Ltd. All rights reserved.