汽轮发电机组轴系扭振多指标非线性协调控制

摘要

为减少机电扰动对汽轮发电机组轴系扭振的影响，在单机无穷大系统中，建立了汽轮发电机组轴系、励磁和调速的六阶非线性状态空间数学模型。基于反馈精确线性化理论，设计了发电机组励磁和调速的多指标非线性协调控制(MINC)策略。同时与线性最优控制(LOC)方法做对比，仿真表明：采用MINC方法，当系统受到短路故障，调功和调压扰动时，不仅能更好地抑制汽轮机和发电机之间功角位移偏差的振荡，减少轴系扭振事故的发生，还可以兼顾各状态量的动、静态性能，提高电力系统稳定运行水平。%To reduce the effect of mechanical and electrical disturbance on torsional vibration of steam-turbine generator shafting, in a single machine infinite system, a six order nonlinear state space model is set up for steam turbine generator shafting based on the generator excitation and speed-regulation system. According to the accurate feedback linearization theory, the multi-index nonlinear coordination (MINC) control strategy is designed for suppressing the torsional vibration of shafting. The strategy is compared with linear optimal control (LOC) method. The simulation results show that when the short-circuit fault occurs and the regulating power and voltage are disturbed, the MINC method can restrain oscillation of the angular displacement deviation between turbine and generator, reduce the risk of shaft torsional vibration, give better consideration of both dynamic and static performance of each state quantity, and stabilize the operation of power system.