The key technologies of smart microgrids mainly include the following: (I) Renewable energy generation technology At present, smart microgrids are mainly based on a variety of renewable energy sources, and the power input is mainly photovoltaic, wind power, hydrogen energy, natural gas, biogas and other mature power generation technologies. (I) Key technologies of energy storage Energy storage is an indispensable part of microgrids. It can play a role in peak shaving and valley filling in microgrids, greatly improving the utilization efficiency of intermittent energy. With the continuous development of science and technology, the current energy storage mainly includes battery energy storage, flywheel energy storage, superconducting magnetic energy storage, and supercapacitor energy storage. The more mature energy storage technology is lead-acid battery, but it has the problems of short life and serious lead pollution. In the future, the marketization of high energy storage, low cost, and high-quality performance graphene batteries will bring spring to the energy storage industry. The current development cost of energy storage technology is relatively high. Countries around the world are working on this technology, but they all have a common goal, which is to achieve the goal of "low cost + high energy storage". (II) Smart microgrid energy optimization dispatching technology Different from the traditional power grid dispatching system, the smart microgrid dispatching system belongs to the horizontal multi-energy complementary optimization dispatching technology, which can fully explore and utilize the direct complementary substitutability of different energy sources, and can not only realize the output of heat, electricity and cold, but also realize the energy exchange of light/electricity, heat/cold, wind/electricity, direct/alternating current. The stratification of various energy sources in the source-storage-load links realizes orderly cascade optimization dispatching to achieve the best energy utilization efficiency. (III) Smart microgrid protection and control technology There are multiple power sources and multiple loads in the smart microgrid. The changes in loads and fluctuations in power sources need to be regulated and controlled by the energy storage system or the external power grid. The regulation, switching and control of these power sources are completed by the microgrid control center. In addition to monitoring the power parameters, switch status, power quality and energy parameters of each new energy generation system, energy storage system and load, the microgrid control center also needs to save energy and improve power quality.