汽轮发电机组次同步谐振评估方法

Subsynchronous resonance evaluation method of steam turbine and generator units

为了能够有效抑制汽轮发电机组普遍存在的次同步谐振(SSR,subsynchronous resonance)问题,采用复转矩系数法对SSR进行评估.计算不同模态下的机械阻尼转矩系数和电气阻尼转矩系数,将两部分进行求和,通过正负来判断稳定性,并对评估结果进行时域仿真验证.基于IEEE第一标准模型,结合电厂参数进行PSCAD/Matlab仿真建模,得到轴系各质量块间扭矩的时域和频域仿真图,将其进行对比分析.结果表明,模态3(频率为27.56Hz)处的综合阻尼为负,扭振幅值比较大,可判断发生了频率为27.56Hz的轴系扭振,故可验证复转矩系数法抑制SSR的有效性.

In order to effectively suppress the subsynchronous resonance of steam turbine and generator units,complex torque coefficient is used to resolve SSR.The mechanical damping torque coefficient and electrical damping torque coefficient in different modes are calculated.The parts are summed and the stability is judged by positive and negative effects,and the results are verified by time domain simulation.Based on the IEEE first standard model and PSCAD/Matlab simulation model,the time domain and frequency domain simulation diagram of torque of each mass in shafting are obtained and analyzed.The results show that the integrated damping at model 3(frequency 27.56 Hz)is negative,the ampli-tude of torsional vibration is relatively large,and the torsional vibration of shafting with frequency of27.56 Hz can be judged.So it can verify the validity of the complex torque coefficient method to suppress subsynchronous resonance.