基于附加阻尼的水轮机调速系统优化控制研究

Research on Optimizing Control of Hydraulic Turbine Governing System Based on Additional Damping

针对水轮机调速系统引发电力系统发生超低频振荡的问题,提出一种调速侧附加阻尼控制策略。首先,基于阻尼转矩法,分析得出水轮机调速系统产生的负阻尼是造成电力系统发生超低频振荡的主要原因;其次,推导调速系统的阻尼转矩系数表达式,证明该系数与水锤效应时间常数及调速器PID参数密切相关;然后,依托附加阻尼控制策略,在系统调速侧引入正阻尼补偿,并采用灰狼优化算法整定调速器PID参数,以进一步改善系统阻尼特性;最后,在Matlab/Simulink仿真平台搭建单机、四机两区域系统进行仿真验证,结果表明所提控制策略能够明显改善调速系统的阻尼特性,有效抑制超低频振荡。

Aiming at ultra-low frequency oscillation in power system caused by hydraulic turbine governing system,an additional damping control strategy for governing side was developed.Firstly,according to the damping torque method,the negative damping generated by the hydraulic turbine governing system was regarded as the main reason for the ultra-low frequency oscillation of the power system.Secondly,the damping torque coefficient expression of the speed regulation system was derived,which proves that the coefficient is closely related to the time constant of water hammer effect and the PID parameters of the governor.Besides,based on the additional damping control strategy,the positive damping compensation was introduced in the speed control side of the system.The grey wolf optimization(GWO)algorithm was applied to optimize the PID parameters to further improve the damping characteristics of the system.Finally,simulation verification in a single-machine system and a four-machine two-area system was executed through Matlab/Simulink.The results illustrate that the proposed control strategy can significantly enhance the damping characteristics of the speed control system and effectively suppress ultra-low frequency oscillation.