Solar Energy Harvesting: Power Electronics Interfaces and Control

Abstract

Abstract Among renewable energy sources such as biomass, tidal, minihydro, microturbines, and wind, solar energy is one of the most promising sustainable energy resources. Solar energy is converted to electrical energy in photovoltaic (PV) cells through a process called photovoltaic effect. The output voltage polarity of the PV cell is direct current (DC) whose magnitude depends on the connection type of PV cells/modules, while the output current or power mainly varies with solar irradiance. One of the primary tasks in PV systems is to convert the output DC voltage of PV modules to alternate current (AC) to energize general‐purpose AC loads and utility connection. In addition, an interface, which regulates and adjusts the output voltage of the PV, is required because the output voltage of the PV system varies with various factors such as irradiation and temperature. Meanwhile, the power extracted from the PV system must be optimized based on the weather conditions to get the highest efficiency. A PV system is a combination of several components such as PV panels, energy storage system (ESS), and power conditioning units (PCUs). In PV systems, PCU is composed of power electronic converters along with special controls/algorithms, and it is responsible for various tasks including ESS charging, maximum power point tracking (MPPT), and DC–AC conversion. This article aims to describe a complete PV system architecture and design by following design steps: PV cell/module/array modeling, MPPT algorithms and implementation, design and control of DC/DC power electronic converters responsible for MPPT operation, and DC/AC inverter to supply general‐purpose AC loads. In addition to the provided basic concepts, an example of a complete stand‐alone PV system design including the system sizing has been presented. The designed system has been simulated, and detailed results are provided.