【摘要】 现代大型汽轮发电机组控制系统的带宽频率与轴系的最低阶扭振模态频率相互趋近 ,控制系统性能的提高受到扭振稳定性要求的制约。文中将未建模扭振模态考虑为刚体转子的模型摄动 ,扭振转速分量是这一模型摄动的结果 ,利用广义观测器估计刚体转速 ,构造出一种新型的扭振滤波器 ,以消除汽轮发电机组控制系统与轴系扭振的相互作用。与常规的扭振滤波器不同 ,所提扭振滤波器能够衰减扭振分量而在通频带无任何附加相位滞后 ,并且提供有可用于鲁棒设计的附加自由度。针对实际工程背景对扭振滤波器提出鲁棒性要求 ,并表示为 H∞ 性能指标的形式 ,利用混合灵敏度方法设计出一种鲁棒 H∞ 扭振滤波器。仿真结果验证了鲁棒 H∞ 扭振滤波器在高频段衰减能力强、在通频带无附加相位滞后、鲁棒性好的优点 ,利用它能够有效防止扭振失稳 ,促进快速响应的高性能控制系统的应用。更多还原

【Abstract】 The bandwidth frequency of the control system and the lowesttorsional m ode frequency of the shafts of the modern turbine generator have the trend to get close to each other.The torsional stability criterion im poses restriction on enhancing the performance of the turbine generator control system .In this paper,the unm odelled torsional dynamics is considered as the model perturbation of the rigid rotor and the torsional speed component is the result of the model perturbation.And then the general observer is used to estimate the rigid speed to form a new type torsional filter to suppress the torsional interaction between the control system and the shafts of the turbine generator.Different from the conventional torsional filter,the proposed torsional filter can reject the torsional com ponent without any additional phase lag in the pass- band.Moreover,it provides additional degrees of freedom for robust design.The robustness specifications of the proposed filter related to the practical condition are developed and form ulated in the form of the H∞ norm.A robust H∞ torsional filter is designed by use of the m ixed sensitivity approach.The simulation results validate that the proposed robust H∞ torsional filter can provide adequate attenuation at high frequencies without any phase lag in the pass- band and has a good robustness.It can effectively prevent torsional in stability and facilitate the practical application of the high speed and high perform ance control system s of turbine generators.更多还原