Variable Structure ADRC-Based Control for Load-Side Buck Interface Converter: Formation, Analysis, and Verification

Abstract

Hybrid energy storage microgrid represents the future direction of distributed energy development. However, under the influence of interference, the dynamic performance of the output side interface will be severely deteriorated. In this article, a linear active disturbance rejection controller with reference differential feedforward and cascade linear extended state observer (ADRC-RDCO) is proposed to deal with unknown modeling error and the unknown dynamics of the interface converter. In this strategy, a cascaded linear extended state observer is introduced to cope with the steady-state offset in the disturbance estimation error, so as to implement the accurate reconstruction of the disturbance state. Furthermore, a control law with RDF is applied to offset a portion of the tracking error of the given signal to achieve the purpose of optimizing the tracking accuracy of the given signal. Then, the tracking performance and stability of ADRC-RDCO are analyzed theoretically. On the basis of discussing the relationship between dynamic characteristics and control parameters, a parameter configuration method is proposed. Finally, the proposed ADRC-RDCO technology was verified on the 40 kW microgrid platform.