基于级联型扩张状态观测器的直流微电网低压负载接口变换器自抗扰稳压研究

直流微电网负载侧供压稳定是实现新能源电力高水平消纳的重要前提。为维持低压负载侧电压稳定，利用级联型扩张状态观测器提高扰动的估计重构精度与速度，将二阶自抗扰控制技术引入低压侧稳压控制。首先，在考虑扰动存在的低压接口变换器动态模型基础上实现对于稳压控制策略的系统设计。之后，在时域上分析级联型扩张状态观测器对于扰动重估精度的提升效果，利用线性等效框架在复频域上分析系统对于总扰动的抑制性能，以及系统模型不确定下对于动态性能的影响。此外，将Lyapunov理论运用于分析所提稳压控制策略的稳定性，表明该系统在工程上稳定。最后仿真实验验证了所提出稳压策略的正确性与有效性，且对于扰动具有较好的抑制性。

Active disturbance rejection and voltage regulation of a DC microgrid low voltageload interface converter based on a cascaded extended state observer

The stability of load side voltage supply in a DC microgrid is an important prerequisite to achieving a high level of new energy power consumption. To maintain the voltage stability of the low-voltage load side, the cascaded extended state observer is used to improve the estimation accuracy and speed of disturbance reconstruction. Second-order ADRC technology is introduced into the low-voltage side voltage regulation control. First, the system design of voltage regulation control strategy is realized based on a dynamic model of a low-voltage interface converter considering the existence of disturbance. Then, the improvement effect of the cascaded extended state observer on the disturbance reconstructed accuracy is analyzed in the time domain, and the total disturbance suppression performance of the system is analyzed in the complex frequency domain by using the linear equivalent framework. The influence of system model uncertainty on the dynamic performance is analyzed. In addition, Lyapunov theory is used to analyze the stability of the proposed voltage regulation control strategy. The analysis shows that the system is stable in engineering terms. Finally, the simulation results verify the correctness and effectiveness of the proposed voltage regulation strategy, and it has good resilience to the disturbance.