基于等效开环过程的VSC-HVDC阻尼控制器协调控制鲁棒稳定性研究

Coordinated Control Robust Stability for VSC-HVDC Damping Controller Based on Effective Open-Loop Process Theorem

针对包含柔性直流(voltage source converter-high voltage direct current,VSC-HVDC)的交直流互联系统区间低频振荡现象,通过多变量系统等效开环过程(effective open-loop process,EOP)理论,将多变量系统回路方程转换为单变量系统回路方程,建立起各回路独立的数学模型。由于包含VSC-HVDC的系统是多输入多输出复杂非线性系统,其中各回路阻尼控制器之间可能存在不协调的问题,基于小增益定理,在实现系统等效开环过程控制的基础上,提出判断各附加阻尼控制器间协调控制鲁棒稳定性指标;设计能抑制低频振荡且能协作运行的发电机电力系统稳定器(power system stabilizer,PSS)附加阻尼控制器和VSC-HVDC附加阻尼控制器。最后在PSCAD/EM TDC中搭建包含VSCHVDC的交直流四机两区域系统,仿真验证所提指标的有效性和所设计控制器的实用性。

According to the phenomenon of low frequency oscillation in the AC-DC interconnected system with voltage source converter-high voltage direct current（ VSC-HVDC）,this paper converts multi-variable system loop matrix equation into many single variable system loop equation,and establishes the independent mathematical models of each circuit,based on multi-variable system effective open-loop process（ EOP） theorem. For the potential uncoordinated problem of each loop controller in multi-input multi-output（ MIM O） nonlinear system which contains VSC-HVDC, this paper proposes a coordinated control robust stability index of each supplementary damping controller based on small gain theorem and EOP theorem. Then,the power system stabilizer（ PSS） supplementary damping controller and VSC-HVDC supplementary damping controller in cooperative operation was designed to restrain low frequency oscillation. Finally,AC / DC four machine two-area system with a VSC-HVDC in PSCAD / EM TDC has been established,and the validity of the proposed indicators and the feasibility of the designed controller have been verified through simulation.