近期，实验室博士生殷允飞作为第一作者，导师刘健行教授作为通讯作者的论文“Observer-Based Sliding Mode Control for Grid-Connected Power Converters under Unbalanced Grid Conditions”已发表在工业电子领域国际权威期刊IEEE Transactions on Industrial Electronics上。

三相不平衡电网下，该论文针对三相两电平电压源型整流器，基于二阶滑模控制技术设计了一种鲁棒控制策略，实现功率-电流协同控制。首先在两相静止坐标系下，建立一个功率-电流协同控制目标，可灵活调整有功和无功功率波动以及三相电流的不平衡度。利用自适应观测器估测三相不平衡电压的正负序分量。基于整流器系统模型、控制目标和自适应观测器，构建电压电流双环控制策略。电流内环基于二阶滑模微分器，设计二阶滑模电流控制器保证电流跟踪其期望值。电压外环基于二阶滑模观测器，设计自抗扰控制器调节输出电压。最后通过实验验证了所提控制策略的有效性。

Abstract

This paper proposes a novel robust control strategy for three-phase power converters operated under unbalanced grid conditions. A consolidated control objective is obtained in the stationary frame, which can be flexibly adjusted according to the degree of oscillation in the active and reactive powers and the balance of the three-phase current. Based on the dynamics of the converter and control objective, a control scheme in a cascaded framework is presented, in which an adaptive observer (AO) is applied to estimate the positive and negative sequences of the grid voltage. In the current tracking loop, a super-twisting algorithm (STA) current controller coupled with a super-twisting differentiator (STD) is implemented to track the current references, featuring rapid dynamics and improved robustness. Additionally, in the voltage regulation loop, an effective composite controller is developed to regulate the dc-link voltage, where a super-twisting observer (STO) is used to estimate the load disturbance, thereby improving the performance of the converter. The experimental results are provided to confirm the effectiveness and  superiority of the proposed control strategy.