提高电力系统稳定性的直流附加阻尼与发电机励磁非线性协调控制

直流附加阻尼控制通常是利用有功功率或频率进行调制,控制目标单一,且不考虑与励磁控制的协调,导致有些情况下不能取得满意的控制效果。为此,该文提出一种协调直流附加阻尼和发电机励磁的微分代数多目标全息反馈非线性控制方法。该方法通过合理确定目标函数并由目标函数构建符合Brunovsky标准型的多目标方程,将非线性空间控制问题转换到线性空间设计;通过对目标函数求导数建立线性空间控制律和非线性空间控制律的等效映射,从而实现对非线性系统目标量的镇定,使其以良好的动态性能达到期望的稳定运行轨迹。将该方法应用于典型四机两区域交直流混合输电系统,设计直流附加阻尼和发电机励磁的非线性协调控制器。仿真结果表明,所设计的控制器在负荷扰动或发生严重短路故障时,均能够通过快速功率和励磁控制稳定系统功角、频率和电压,有效提高系统的稳定性和控制鲁棒性。

Coordinated Nonlinear Control of HVDC Supplementary Damping With Generator Excitation for Enhancing Stability of Power System

HVDC supplementary control usually takes active power or frequency as only objective for modulation and usually considers no coordination with excitation,which results in unsatisfied performance in some cases.To solve this problem,a multi-objective holographic feedback nonlinear control method based on differential algebraic equation(DAEBMOHF)is proposed to coordinate HVDC supplementary damping and generator excitation.In this method,the nonlinear control problem is converted into linear space to be solved by constructing the multi-objective equation conformed to Brunovsky normal form with appropriately designed objective functions.Equivalent map between nonlinear and linear control laws is connected by calculating derivative of the objective functions to realize nonlinear control of objective functions and makes them attain expected stable orbits.A practical controller of a 4-machine 2-area system is designed with the DAEBMOHF method.Simulation results demonstrate that the proposed control method can effectively stabilize rotor angle,frequency and voltage with power and excitation control and improve stability and robustness.