新型改进内模解耦控制的STATCOM电流环控制方案设计

Current Loop Controller Design of STATCOM Based on the New Improved Internal Model Decoupling Control

静止同步补偿器的d-q坐标模型为非线性耦合系统,传统的交叉解耦控制难以适应模型失配工况;而内模解耦控制虽对模型参数具有鲁棒性却存在暂态振荡问题。因此,提出一种改进型内模控制方案。首先,分析了交叉解耦、内模解耦的模型,推导出耦合项引发电流振荡的原因。其次,引入自抗扰控制器替代积分器,通过扩张状态观测器与非线性反馈律对扰动补偿。提出新颖的非线性误差观测函数fall(),利用fall()设计出新型的自抗扰控制器,并通过线性化变换方法证明了此类自抗扰控制器的稳定性。最后,通过仿真与实验对交叉解耦、常规内模解耦、新型内模解耦进行对比,表明新型方案的响应最好,对扰动具有较强的鲁棒性。

The mathematical model of static synchronous compensators in the d-q coordinate system was a nonlinear coupling system. The cross decoupling control was difficult to adapt the model mismatch conditions. The internal model control was robust for system parameters, but it had the transient oscillation problem. A new internal model controller was presented. Firstly, the mathematical model of cross decoupling control and internal model control was analyzed and the current transient oscillation is deduced. Secondly, the active disturbance rejection control was used to replace the internal model decoupling integrator. The extended state observer and nonlinear state error feedback were used to avoid the problem of transient oscillation. A new nonlinear state error feedback functionfall（） was proposed. The stability of the new active disturbance rejection controller usingfall（） was proved by a linearization scheme. Finally, the simulations and experiments of cross decoupling, conventional internal model decoupling and the new internal model decoupling were compared. Results show that the response of the new decoupling scheme is the best and it has stronger robustness.