Defining Photovoltaic Mission Profile for the Pre-Design of Static Converters

A methodology is presented for accurately defining the mission profile and relevant operating conditions of photovoltaic systems. The proposed method works as a tool for obtaining useful information for designing high-efficiency and reliable photovoltaic power converters. This methodology enables modern design techniques of pre-sizing and optimizing power converters according to its mission profile and relevant operating conditions. Two cities in different climate zones were analyzed and compared, wherein a large dataset of solar irradiance and ambient temperature from each location was used. Meteorological measurements from ten years were used to obtain an average typical year of weather conditions for both cities. In-plane irradiance on photovoltaic panels for an annual operation was estimated. A mathematical model was used to analyze solar incidence on modules in fix mounting and with the use of mechanical trackers. A photovoltaic system's operating current, voltage, and temperature levels were estimated in relationship to in-plane irradiance and ambient temperature. Energy yield throughout one year was obtained based on the average typical weather condition. An analysis is presented regarding how climate affects photovoltaic operation and what are the most relevant current and voltage levels for each mission profile; these levels are the starting point for an accurate converter design. Validation results of photovoltaic modeling are presented for a fourteen-panel system of 3.29 kW installed capacity. The impact of using mechanical trackers on power processing is also presented. A discussion is made on the importance of previous knowledge of an accurate photovoltaic mission profile on the design of power converters and on maximizing energy processing.