转子绕组短路故障时发电机转子不平衡电磁力分析  

Analysis on Rotor Unbalanced Electromagnetic Force of Generator under Rotor Interturn Short Circuit Fault

作　　者：周国伟[1] 李永刚[1] 万书亭[2] 张玉[2] 李和明[1] 

机构地区：[1]华北电力大学电力工程系,保定071003 [2]华北电力大学机械工程系,保定071003

出　　处：《电工技术学报》2012年第10期120-127,共8页Transactions of China Electrotechnical Society

基　　金：国家自然科学基金(51177046);河北省自然科学基金(E2011502024)资助项目

摘　　要：转子绕组短路是发电机常见的电气故障之一,将导致转子振动,危及电机和系统的安全。为了深入分析转子绕组短路故障引起转子振动的成因,提出了一种转子绕组短路故障时转子不平衡电磁力的磁动势叠加计算方法,同时改进了现有的等效磁通计算方法。然后以某火力发电厂QFR—400—2—20型发电机转子绕组短路故障为工程背景,分别利用等效磁通计算方法和磁动势叠加计算方法分析计算了不平衡电磁力,指出由于等效磁通计算方法没有考虑短路位置对不平衡电磁力的影响,当靠近转子横轴的槽绕组短路时,计算得到的不平衡电磁力大于利用磁动势叠加计算方法计算得到的不平衡电磁力。The rotor winding turn-to-turn short circuit fault is one of the main electrical faults of turbo-generators,which can cause the rotor vibration,and greatly affect the security of the generator and the power system.In this paper,firstly,the magnetomotive force superposition method of the unbalanced electromagnetic force acting on the rotor is proposed,and the equivalent magnetic flux method is improved.Then the rotor interturn short circuit fault of a QFR—400—2—20 type generator in a power plant is investigated,and the value of the unbalanced electromagnetic force is respectively calculated by the equivalent magnetic flux method and the magnetomotive force superposition method.The result shows that when the interturn short circuit turns are near the Q-axis,the unbalanced electromagnetic force that obtained by the equivalent magnetic flux method is larger than the value that calculated by the magnetomotive force superposition method because the former method doesnot consider the effect of the interturn short circuit position on the unbalanced electromagnetic force.

关 键 词：发电机 转子绕组短路 不平衡电磁力 等效磁通计算方法 磁动势叠加计算方法 

分 类 号：TM351[电气工程—电机]