Overview

To make the most efficient use of wind, solar, and other renewable energy sources, key technologies such as grid connection, energy storage control, electric vehicle connection, and microgrid control must be put into place. Grid connection of new energy sources can be divided into two major types: centralized and distributed. The centralized method refers to directly connecting a large-scale photovoltaic (PV) power station or a large-scale wind farm as a single large power source to the macrogrid (not discussed in detail in this book), whereas the distributed method refers to connecting decentralized PV power generators and wind turbines to the grid by combining the technologies of energy storage and electric vehicle connection, realizing local consumption of PV power and wind power. This chapter first discusses basic concepts, characteristics, and advantages of distributed energy resources and explains the purpose of the book as a whole: to explain practical distributed energy resource grid connections, in particular controllable flexible grid connection technology for distributed PV generation and wind power generation, energy storage and electric vehicles, adaptive grid active management technology, and "plug-and-play" grid connection technology for distributed resources. The chapter then lists and explains requirements for grid connection of distributed energy resources, including safe connections, information interconnections, control of high-capacity penetration, and unification of power electronic resources conversion. Finally, the key technologies needed for effective grid connection of distributed resources are discussed and two main modes for grid connection are introduced: the PV and energy storage all-in-one (AIO) machine, and the microgrid.