大型超(超)临界发电机组匝间短路及相应保护配置分析

Large ultra(ultra) supercritical turbine generator interturn short circuit and appropriate protection configured analysis

对于大型超(超)临界机组发生匝间短路故障,随着电抗的增大和定子绕组、电阻的减少将使短路电流水平下降,导致保护的灵敏度降低,因此普通的保护如横差保护和不完全纵差保护等将不能应用于大型超(超)临界汽轮发电机.实践证明,发电机发生匝间短路故障后,随着短路匝数的增加,转子二次谐波电流以及单元件横差电流均有较大的变化,以此构成的相应保护方案将能够可靠动作.着重讨论了匝间短路后各电气量的变化对继电保护的影响以及匝间保护在实际中的应用.

As the reactance increases and the stator windings ,the resistance will decrease down to the level of short cir- cuit current protection sensitivity. Some protection as the previous transverse differential protection and incomplete differ- ential protection will not be used for large ultra（ultra） supercritical turbine generator. Practice shows that inter-turn short circuit generator failure occurred, with the increase of short circuit turns the rotor harmonic currents and unit transverse differential current changes are larger,thus constitutes the appropriate action protection program will be able to reliably. This paper focuses After discussion of the turn to turn short-circuit the electrical changes in the amount of on Protection and turn to turn protection how to apply in practice.