ABSTRACT
The growing requirements of clean energy production caused by the persistent demands of environmental protection and energy independence have led to increased attention being focused on renewable energy sources. Among various renewable energy technologies, photovoltaic (PV) power systems represent a very promising solution based on the electricity cost and flexibility of utilization. The preference for using solar energy is due to the tremendous potential inherent in the solar radiation that strikes the Earth’s surface. The coverage of area by PV stations of only about 2%–3% in the vicinity of the equator is sufficient to supply all the electricity needs of humanity. The recent progress in the PV power stations reflects the modern trends of the change from conventional fossil fuel-based electro-generating facilities to renewable ones. Solar electricity takes the first place in this list, especially in the countries that are in the wide zone, from −60° until +60° from the equator line. Despite its multiple advantages, PV technology also presents a few challenges, such as the unstable character of output power, daily and season dependence, etc. The most problematic issue is the need for permanent control of PV characteristics, thus ensuring maximum power at every point in time. The maximum power point tracking (MPPT) systems are connected with PV solar plants to provide maximum output power. The primary aim of the MPPT is to adjust the control parameter (either a voltage or current) to as close to the operating point as possible, thus ensuring the global maximum (GM) of power production. Different control approaches and electronic schemes of MPPT devices have been proposed and discussed. The wide range of possible solutions requires rigorous classification and deep analysis. This chapter presents a catalog of the existing MPPT technologies (determinizing or stochastic procedures) applicable in different conditions and the functionality analysis. Emphasis is placed on solutions such as inhomogeneous solar irradiation and partial shading conditions, especially for large PV plants. An additional criterion for the analysis was the accuracy and search time of the maximum power working point.
