多相无刷励磁机旋转二极管开路故障在线检测方法  

Online Detection Method of Open Circuit Fault of Rotating Diode in Multi-phase Brushless Exciter

作　　者：武玉才[1] 孙淑琼 WU Yucai;SUN Shuqiong(State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources(North China Electric Power University),Baoding 071003,China)

机构地区：[1]新能源电力系统国家重点实验室(华北电力大学),河北保定071003

出　　处：《中国电力》2023年第8期99-108,共10页Electric Power

基　　金：国家自然科学基金资助项目(52277048);河北省自然科学基金资助项目(E2020502064)。

摘　　要：针对多相无刷励磁机旋转二极管开路故障不易检测的问题,以39相11对极无刷励磁机为例,从无刷励磁机正常运行和单管开路故障时的电枢电流特性入手,首先,分析了2种状态下电枢磁场的变化规律,根据励磁机的结构特点及电磁耦合关系,提出在励磁机内定子的任意磁极上安装一个磁场检测线圈用以检测旋转二极管开路故障。其次,结合无刷励磁机空间磁场的谐波特征,推导出检测线圈的磁通表达式,进而得到检测线圈的感应电压,发现二极管开路故障会引起感应电压中特定频率谐波幅值变化。最后,通过有限元仿真,证明该检测线圈法可以有效识别出旋转二极管开路故障,且不影响无刷励磁机正常运行。Aiming at the open-circuit detecting difficulty of the rotating diode of polyphase brushless exciter,the 39-phase-11-pole brushless exciter is taken as the example in this paper,the armature current characteristics of the brushless exciter during normal operation and single-tube open-circuit fault are analyzed.Firstly,the change law of armature magnetic field in two states is analyzed,a magnetic field detection coil is proposed to be installed on any pole of the stator in the exciter according to the structural characteristics of the exciter and electromagnetic coupling relationship.Then,combining with the harmonic characteristics of the spatial magnetic field of the brushless exciter,the flux expression of the detection coil is derived,and the induced voltage of the detection coil could be obtained.Specifically,it is found that an open diode fault causes a change in the amplitude of a specific frequency harmonic in the induced voltage.Finally,the finite element simulation proves that the detection coil method can effectively identify the rotating diode open circuit fault without affecting the normal operation of the brushless exciter.

关 键 词：无刷励磁机 二极管开路 感应电压 检测线圈 谐波特征 

分 类 号：TM623[电气工程—电力系统及自动化]