What does the third-level unit of State Grid mean?

Municipal power supply company. Municipal companies belong to the third-level units in the State Grid Corporation system. According to the hierarchy, the units in the State Grid Corporation system can be divided into four levels, among which: the first level unit is the company headquarters, the second level unit is the provincial electric power company, the third level unit is the prefecture-level power supply company, and the fourth level unit is the county-level power supply company. Therefore, the third-level units of State Grid Corporation refer to prefecture-level power supply companies.