The Study Of New Arc Suppression And Earthing Fault Compensation Device Using IGBT

With fast growing economy of our country, the needs of power are also increased. The safety and stability of power energy has reached a high level. Especially, the rebuild of city and countryside power grids, a mass of electric power cable is used, which make the capacitance between transmission line and ground larger. Under this condition, the arc of earthing fault can not be extinguished automatically when earthing fault occured, at the same time, the overvoltage that intermittent arc makes will lead to expanding fault. Because of low adjusting precision, slow speed and small adjusting scope, the existed arc suppression coil system will be replaced by automatic tracking arc suppression system. In recent years, all kinds of new automatic compensation devices have been running in power grids to improve the safety and stability of power system.In this thesis, the basic principle and applied instance of current automatic tracking arc suppression compensation system are analyzed, and then the new device is proposed. It can produce continuous adjusting current, larger adjusting scope, rapid speed, and higher precision. Different from arc suppression coil, resonant danger will not occur in power grids.The basic principle of the new earthing fault compensation device based on IGBT is proposed, and related simulation will be performed using PSCAD/EMTDC and MATLAB and result shows that it can compensate earthing current effectivly. Methods of capacitance measurement are discussed in this paper, and then the suitable capacitance measurement method is proposed. The controller and related circuit will be given in the end.