With the increasing demand for the controllability and flexibility of primary equipment in power system and the fast development of power electronic technology
more and more power electronic equipment is applied. In this paper
power electronic primary equipment in power system is collectively called flexible primary equipment. From this point of view
this paper firstly reviews the research progress and engineering applications of flexible primary equipment and their key technologies in flexible AC transmission system
flexible DC transmission system
renewable energy power generation
power energy storage
active distribution system and microgrid. Then the key generic technologies of flexible primary equipment are analyzed