含有调速器多死区环节的风水火系统频率稳定分析

Frequency stability analysis of a wind-hydro-thermal system with a governor multi-dead-zone link

“双高”背景下新型电力系统面临着非线性机理复杂的稳定问题,传统机组调速器与风电控制器中死区非线性组合间的相互作用,在一定程度上影响了系统的频率稳定性。为此,在奈氏定理的基础上探究不同死区非线性组合下系统频率振荡的影响规律,主要针对死区类型、死区大小和死区顺序3个方面进行研究,涉及单死区系统和多死区系统。理论分析了其非线性系统的稳定性,并根据稳定极限环条件求解系统的临界振幅和振荡频率。通过改变死区类型及顺序,影响机组对系统频率的支撑能力,指出了系统频率稳定与临界振幅的关系,并在Matlab/Simulink中对上述理论分析进行了仿真验证。结果表明机组死区大小和类型均会改变系统的临界振幅和振荡频率,为机组配置死区提供了一定的参考依据。

Under the“double high”background,the new power system is faced with the stability problem of complex nonlinear mechanisms.The interaction between the nonlinear combination of the dead zone in the traditional unit governor and the wind power controller affects the frequency stability of the system to a certain extent.Therefore,on the basis of Nye’s theorem,the influence law of system frequency oscillation with different dead-zone nonlinear combinations is explored,mainly focusing on three aspects:dead-zone type,size and order,involving both single and multi-dead-zone systems.The stability of the nonlinear system is analyzed theoretically,and the critical amplitude and oscillation frequency of the system are determined from the stable limit cycle condition.By changing the type and order of the dead zone,the ability of the unit to support the system frequency is affected,and the relationship between system frequency stability and the critical amplitude is pointed out.The above theoretical analysis is simulated and verified in Matlab/Simulink.It is concluded that the size and type of the unit dead zone will change the critical amplitude and oscillation frequency of the system.This provides a certain reference for the unit to configure the dead zone.