大型发电机组磁极线圈匝间短路故障分析及处理

Analysis of turn-to-turn short circuit fault of magnetic pole coil of large hydro generator and solution

发电机在运行的过程中,转子通常会受到电、热以及机械应力的作用,如果转子的制造工艺不良,那么随着运行年限的增加,转子磁极绕组就可能会出现匝间短路故障。当转子磁极绕组匝间发生的短路较严重时,就会使转子的电流显著增大,转子绕组的温度也会升高,从而限制发电机无功功率的输出;同时,机组的振动也会加剧,影响到机组的安全运行。以二滩水电站水轮发电机组产生的振摆问题为例进行了分析研究,特别是针对转子磁极匝间短路故障,在分析研究的基础上,提出了相应的解决方法和措施,在事故现场进行检查和测量,使出现的问题得到了圆满地解决。介绍了交流阻抗法在二滩水电站3号发电机组磁极线圈匝间短路故障分析中的应用以及应注意的事项。可为同类大型水轮发电机处理此类缺陷提供参考。

The generator runs under the influence of electric,thermal and mechanical stresses.If the rotors are poorly manufactured,the turn-to-turn short circuit fault of the magnetic pole coil might occur as the operation time increases.Severe turn-to-turn short circuit of magnetic pole coil will significantly increase the rotor current and the temperature of the rotor winding and restrict the reactive power output of the generator.Meanwhile,the vibration of the generator unit will also increase and affect the safe running of the generator unit.Taking the problem of vibration and swing in the generating unit of Ertan Hydropower Station as an example,we carried out the analysis on the short circuit fault,especially on the turn-to-turn short circuit fault,and put forward the solution and countermeasures.The in-site inspection and measurement showed that the problem was solved satisfactorily.We introduced the application of AC impedance method in the analysis of the turn-to--turn short circuit fault of magnetic pole coil of unit 3 of Ertan Hydropower Station and some attentions.