次同步谐振的暂态扭矩放大问题研究

Research on Transient Torque Amplification of Subsynchronous Resonance

分析串补引起的暂态扭矩放大(transient torque amplification,TA)的危害和发生条件,提出影响电厂机组TA问题严重程度的因素主要包括暂态故障清除时间和机组轴系的自然扭振频率。暂态故障清除时间为轴系主导扭振频率的半波长的奇数倍时,TA问题最严重;系统的电气谐振频率与机组轴系频率吻合得越好,串补度越高,TA问题越严重。以锡盟地区的A电厂和B电厂为例,采用电磁暂态仿真法和复转矩系数法进行计算分析,验证上述结论的正确性。最后比较分析阻塞滤波器(blocking filter,BF)与负反馈性质的机端次同步阻尼控制器(generator terminal sub-synchronous damping controller,GTSDC)对缓解TA的作用效果,结果表明与负反馈性质的次同步谐振(sub-synchronous resonance,SSR)抑制措施相比,BF对于TA的预防抑制效果要好很多。

This paper analyzes the principle and harm of Transient Torque Amplification(TA),and puts forward the factors that affect the severity of TA problems in power plants,including the clearing time of transient faults and the natural torsional vibration frequency of shafting.When the removal time of transient fault is odd times of half wavelength of the dominant torsional vibration frequency of the shaft system,TA problem is the most serious;The better the electrical resonance frequency of the system is in accordance with the shafting frequency of the unit,the higher the series compensation degree is,the more serious the TA problem is.Taking A power plant and B power plant in Ximeng area as examples,the electromagnetic transient simulation method and complex torque coefficient method are used for calculation and analysis to verify the correctness of the above conclusions.In terms of the measures to solve the TA problem,the Blocking Filter(BF)and Generator Terminal Sub-synchronous Damping Controller(GTSDC)with negative feedback property are compared to analyze the effect of TA suppression.The results show that compared with the negative feedback SSR inhibition measures,BF has a better effect on TA prevention and inhibition.