Key technologies for grid connection of distributed resources

Abstract Distributed energy resources typically feature randomness, intermittence, and fluctuation, and connecting them to the power grid affects the safety and stable operation of the grid to a certain extent. This chapter discusses the related key technologies, such as safety connections for distributed resources, islanding prevention and protection, abnormal voltage and frequency autocontrol, seamless microgrid connection and disconnection, and active grid protection control. It provides detailed descriptions of the theoretical foundations and covers simulation and experimental verification. Engineering applications of the key technologies for grid connection of distributed resources are also presented in detail. Supported by over 50 figures and 11 tables, the chapter is a thorough source of information on the latest connection technologies being used and/or developed for distributed power. Key topics covered include presynchronous grid-connection control technology; microgrid control, including bus dominant hybrid microgrid coordination control technology and frequency-shift-keying (FSK) technology for microgrid; and synchronous generator control technology.