Grid-Connected Photovoltaic Generation Plants: Components and Operation

Abstract

Abstract-The main design objectives of photovoltaic (PV) systems have been for a long time to extract the maximum power from the PV array and to inject it into the AC grid. Therefore, the maximum power point tracking of a uniformly irradiated PV array and the maximization of the conversion efficiency have been the main design issues. But also, when the PV plant is connected to the grid, special attention has to be paid to the reliability of the system, the power quality and the implementation of protection and grid synchronization functions. Modern power plants are required to maximize their energy production requiring suitable control strategies to solve the problems related to the partial shading phenomena and different orientation of the PV modules towards the Sun. Moreover, the new policy concerning the injection of reactive power into the grid makes the development of suitable topologies and control algorithms mandatory. A general view of actual solutions for applications of the PV energy systems is presented. The paper covers some important issues such as the most reliable models used for simulation that are useful in the design of control systems, and the maximum power point tracking function, especially in distributed applications. The main topologies used in the PV power processing system and, finally, grid connection aspects are discussed, especially as far as synchronization, protections and integration are concerned.

A variance-constrained approach to recursive state estimation for time-varying complex networks with missing measurements

“…Then, we can see that (15) holds by taking (17) and (18) into account. The proof of this Theorem is complete.…”

“…Theorem 3 Consider the one-step prediction error covariance P k+1|k and the estimation error covariance P k+1|k+1 in (14)- (15). Let ǫ k+1 and γ k be positive scalars.…”

“…Subsequently, let us handle the second term of the righthand side of (15). By using the elementary inequality…”

“…As is well known, the scale-free networks and small-world networks are two popular classes of complex networks characterized by the power-law degree distributions and the short path lengths as well as high clustering [1,23]. Noting the importance and popularity of the complex networks, increasing research attention has been devoted to various aspects of the network structure [14,15,26]. During the past decade, the dynamics analysis of the complex networks has become a very active topic of research due to its application potentials in a wide range of realworld networks such as biological networks, computer networks, electrical power grids, cyber-physical systems, social networks and technological networks.…”

Photovoltaic generators interfacing a DC micro-grid: Design considerations for a double-stage boost power converter system

“…To address these issues, governments around the world have set targets in generating electricity from clean resources such as wind, solar, geothermal, hydroelectric and fuel cells. Among these resources, over the last few years the installed capacity of solar PV generators have experienced huge growth due to their improved efficiency and reduced cost per watt [1].These improvements make solar energy one of the most promising renewable sources in electricity generation. Of note is that the main challenges in connecting distributed generators (DGs) to the main grid are: synchronization, harmonics, voltage rise, circulating current and instability caused mainly by an increased number of connected DGs.…”