Past, today and future development of micro-grids in China

Micro-grids have been developed for over two decades as building blocks for future smart grids. Micro-grids have appeared with the advantages such as control flexibility, easy connection of renewable resources, high efficiency and immunity to large area blackouts. Similar to other countries, development of micro-grids in China has gone through from the early stage of AC microgrids to the current varieties of AC, DC and hybrid AC/DC micro-girds based on their applications. Many technical problems have been solved and new problems are continuously appeared during the development process. This paper presents a past, today and future for development of micro-grids in China. The current status of micro-grids and renewable energy sources in China is presented first. The topologies of the micro-grids in China are then introduced and classified into three types. Different control techniques of the micro-grids are introduced. Finally, technical challenges and future prospect of micro-grids in China are discussed.