感应电动机对称电压跌落临界清除时间解析算法  

An Analytical Method to Calculate Critical Clearance Time of Symmetrical Voltage Sags for Induction Motors

作　　者：王志军[1] 朱珂[1] 王小宇[2] 

机构地区：[1]山东大学电气工程学院,山东省济南市250061 [2]卡尔顿大学电子工程系

出　　处：《电网技术》2014年第2期509-514,共6页Power System Technology

摘　　要：针对电压跌落易触发电动机的保护动作而引发感应电动机停机的问题,提出了一种快速计算感应电动机对称电压跌落临界清除时间的解析算法。该算法基于感应电动机电磁转矩-滑差曲线与机械转矩-滑差曲线之间稳定与不稳定平衡交点的概念和感应电动机稳态等效电路,将电动机的一阶运动微分公式转化为时间关于滑差的解析方程。此外,还提出一种判定对称电压跌落是否为绝对安全电压跌落的算法。电磁暂态仿真实验验证了所提方法的有效性。所提解析算法有助于实现感应电动机的智能保护,减少非必要停机的概率。In allusion to induction motor stalling due to protection actions easily triggered by voltage sags, an analytical algorithm to fast calculate the critical clearance time of symmetrical voltage sags for induction motors is proposed. Based on the concept of intersection points of stable equilibrium and unstable equilibrium between electromagnetic torque-slip curve and mechanical torque-slip curve of induction motor and the steady state equivalent circuit of induction motor, the first-order differential motion equation of the motor is turn into an analytical time-slip function. Besides, an algorithm to judge whether the symmetrical voltage sag is absolutely safe is put forward. The effectiveness of the proposed method is validated by the results of electromagnetic transient simulations. The proposed analytical algorithm contributes to implement the intelligent protection for induction motors and decrease the probability of unnecessary stalling of induction motors.

关 键 词：对称电压跌落 临界清除时间 感应电动机 绝对安全电压跌落 

分 类 号：TM346.2[电气工程—电机]