电力系统电压等级与变电站继电保护（Voltage level of power system and relay protection in Substation）.doc

电力系统电压等级与变电站继电保护（Voltage level of power system and relay protection in Substation） Baidu space | Baidu home page | login SPY-FOOLNO GOD home page blog album | personal files | friends see article Power system voltage class and substation relay protection 2009-08-16 19:56 power system voltage class has 220/380V (0.4 kV), 3 kV, 6 kV, 10 kV, 20 kV, 35 kV, 66 kV, 110 kV, 500, 220 kV, 330 kV, and two kV. With the improvement of motor manufacturing technology, 10 kV motors have been produced in large quantities, so 3 kV and 6 kV have been used less frequently, and 20 kV and 66 kV are seldom used. The power supply system is based on 10 kV and 35 kV. The transmission and distribution system is mainly over 110 kV. Power plants, generators have 6 kV and 10 kV two, and now 10 kV based, users are 220/380V (0.4 kV) low-voltage system. According to the provisions of the rules provisions of city electric power network design: transmission network of 500 kV, 330 kV, 220 kV, 110kV, 110kV, 66kV high voltage distribution network, distribution network for 20kV, 10kV, 6 kV, 0.4 kV low voltage distribution network (220V/380V). The power plant emits 6 kV or 10 kV electric power plant, in addition to their own use (power plant), can also use 10 kV voltage to the user in the vicinity of power plant, 10 kV power supply range of 10Km, 35 kV 20~50Km, 66 kV 30~100Km, 110 kV 50~150Km, 220 kV 100~300Km, 330 kV 200~600Km, 500 kV 150~850Km. 2. types of Substation Various voltage levels of power systems are converted through power transformers, the voltage rise is step-up transformer (substation is step-up station), and the voltage is reduced to step-down transformer (substation is step-down station). A double loop transformer that selects two coils (windings) for voltage to another; a three loop transformer with three coils (windings) for which the voltage is changed to two voltages. In addition to the step-up substation and step-down, it is also divided into hub stations, regional stations and ter