基于功率原理的新型发电机不对称故障保护  

A New Generator Asymmetric Fault Protection Based on Power Principle

作　　者：金明亮[1] 尹项根[1] 游大海[1] 

机构地区：[1]华中科技大学电力安全与高效湖北省重点实验室,湖北省武汉市430074

出　　处：《电力系统自动化》2010年第11期82-86,共5页Automation of Electric Power Systems

基　　金：国家自然科学基金资助项目(50837002;50877031)~~

摘　　要：基于两相坐标系统,对发电机内部不对称故障进行研究发现,瞬时功率中不平衡功率增加而平衡功率下降,解释了该现象的物理原因,提出了瞬时功率不对称度定义,其大小为不平衡功率与平衡功率的比值,且该值能灵敏反映发电机内部不对称故障。以瞬时功率不对称度为主要判据,结合发电机外部故障时不平衡功率相位会出现反相突变的特点提出了一种新型发电机不对称故障保护。动模试验结果表明,该保护能切除少匝数不对称短路故障,对大匝数故障、异相短路故障和振荡中故障均有很高的灵敏度和可靠性;而且接线简单,易与其他类型保护集成互补使用。The study based on the two-phase coordinate system shows that when an asymmetric fault occurs within a generator the unbalanced power component of the instantaneous power output increases while the balanced power component decreases.A new definition of instantaneous power asymmetry degree is presented.It is defined as the ratio of the unbalanced power to the balanced power and it sensitively reflects the asymmetry of faults internally happening in a generator.A new generator protection principle is proposed based on the instantaneous power asymmetry degree and the phase mutation of the unbalanced power.Dynamic simulation results show that the principle can remove small-number-turn faults with high sensitivity.In case of large-number-turn faults,phase to phase faults or faults happening during a system swing the protection can operate quickly and reliably.The wire connection is simple and the protection is easy to be embedded into other protection functions as a complementary function.

关 键 词：瞬时功率不对称度 平衡功率 不平衡功率 动模试验 相位突变 

分 类 号：TM307.1[电气工程—电机]