静止同步串联补偿器的系统级协调控制策略研究

Study on Coordinate Control Strategy of Static Synchronous Series Compensators in System Level

提出了一种励磁与静止同步串联补偿器(SSSC)之间的协调控制方法。针对系统的仿射非线性方程,首先通过精确反馈线性化方法(EFL)将系统非线性因素转换到含有控制输入的状态方程中。系统参数的不确定、模型的不精确通过坐标变换最终反映到转换后的非线性部分。进而利用扩张状态观测器(ESO)观测该非线性部分,实现了线性化并提高了EFL对于参数不确定、模型不精确的弱鲁棒性。线性函数被应用于ESO,避免了以往ESO求解过程中参数众多、求解复杂的缺点。最终,励磁与SSSC之间实现了解耦,并由此得到了协调控制方法。介绍了应用电磁暂态仿真软件PSCAD/EMTDC搭建的系统以及控制器数字模型。仿真结果证实了所提出的协调控制方法具有较高的鲁棒性,可大幅度提高系统稳定性。

A method of the coordinated control between the exciter and the static synchronous series compensator（SSSC） was proposed.For the affine nonlinear equation of the system,firstly,the nonlinear elements of the system were transformed into the state equation containing the control input by exact feedback linearization（EFL） method.The uncertainty of the system parameter and the inaccuracy of the model were finally reflected in the transformed nonlinear part by the coordinate transformation.And then the extended state observer（ESO） was used to observe the nonlinear part,which realized the linearization and improved the weak robustness of the EFL on the parameter uncertainty and the model inaccuracy.The linear function was applied in the ESO,avoiding the disadvantages of numerous parameters and complicated solving in the previous ESO solving process.At last,the exciter and the SSSC were decoupled,and consequently the coordinated control method was obtained.The mathematical models of the system and controller built by applying the electromagnetic transient simulation software PSCAD/EMTDC were described.Simulation results proved that the proposed coordinated control method has a higher robustness and can greatly improve the stability of the system.