State Grid and Huadian Group are central enterprises in the power industry, and they are in a parallel relationship. Just like China Mobile and China Unicom, in order to break the monopoly, they artificially create competition. State Grid Corporation is a power supply enterprise, which is mainly responsible for the power grids of all provinces except China Southern Power Grid Corporation. Huadian Corporation is a central power generation enterprise and one of the top five power generation companies, mainly including power plants and other power enterprises. Power grid companies directly manage substations, which are generally managed by power supply bureaus or EHV bureaus. The maintenance or renewal of power equipment belongs to the investment of power grid companies. Regardless of the power plant, the power supply bureau originally belonged to the former state power company. After the power plant was separated from the power grid, it became two enterprises.