双馈发电机转子绕组中性环结构与故障分析研究

Fault analysis and structure of doubly-fed induction generator rotor winding neutral ring

针对某型双馈发电机在风电机组运行过程中出现的转子绕组中性环故障问题,对中性环结构与故障现象进行了分析与研究。采用ANSYS Workbench开展了中性环结构静力学与模态分析,利用微观分析技术对非故障发电机与故障发电机中性环连接块进行了取样分析;根据故障发电机中性环连接块微观检查发现的异常现象,对剩余连接块进行了金相组织检查;最后建立了中性环结构设计、连接块金相组织与中性环故障的关系。研究结果表明:中性环应力集中与连接块氢脆为引发中性环故障的原因;根据故障原因提出缩短连接块长度、避免异形弯曲、采用无氧铜等预防措施,可为后续产品优化与故障原因分析提供参考依据。

Aiming at the rotor winding neutral ring problem of a double-fed induction generator in the process of operating, the structure and the failure phenomenon of the double-fed generator rotor winding neutral ring were analyzed and investigated. The statics and modal analysis of a double-fed induction generator＇s neutral ring were used based on the ANSYS Workbench, and the micro observation contrast analysis of the fault generator and non-fault generator＇s neutral ring connection lead was used. Due to the fault generator＇s abnomlal phenomena was found by micro observation checking, the metallographie structure inspection was done for the other neutral ring connection lead of the fault generator. Finally, the relationship between the neutral ring＇s structure, the connection lead＇s metallographie structure and the neutral ring fault was established. The experimental results show that the neutral fault reason is the neutral ring＇s structure stress concentration and the neutral ring connection lead＇s hydrogen embrittlement. According to the cause of failure, the shortening length of the neutral ring connection lead, avoiding the special-shaped structure, using the oxygen-free copper solution are presented to prevent the rotor winding neutral ring problem. And, it provides reference basis for the product optimization and reason analysis in the future.