Enhancement in Robust Performance of Boost Converter-Based Distributed Generations Utilizing Active Disturbance Rejection Controller

This paper presents a comprehensive model of a DC/DC boost converter interfaced with all types of local loads. As known, the presence of constant power loads (CPLs) may cause stability-related issues. To mitigate such destructive effects, an active disturbance rejection control (ADRC) technique is employed in this paper to improve the boost converter performance from the stability point of view and to tackle the voltage tracking control problem during load variations. External disturbances on the controlled objects are estimated by an extended state observer (ESO), and subsequently compensated by a state error feedback (SEF) in the presence of a tracking differentiator (TD) in the feedforward direction of the control loop. The closed-loop stability of the tracking error system with the ESO is also proved using Lyapunov theory. To evaluate the system’s performance, the root locus method is utilized, investigating the impacts of each load type on the system stability (1 DOF uncertainty). The Kharitonov theorem alongside the zero exclusion condition (ZEC) is also applied to evaluate the system’s robust stability in case of multi-parameter uncertainties. Since the implementation of the proposed ADRC becomes challenging as the order of the system increases, a well-known model order reduction (MOR) method is introduced to lessen the computational complexity. Indeed, the full-order model (FOM) is replaced by the reduced-order model (ROM) here using the iterative rational Krylov algorithm (IRKA) method based on the moment matching concept and Krylov subspaces. A comparison between the proposed control method, the traditional PI controller, and optimal control approaches is also provided. The numerical results carried out in MATLAB/SIMULINK software confirm the effectiveness of the suggested compensator. Note to Practitioners—For the sake of clean energy and as a remedy for environmental issues such as global warming, renewable energy sources (RESs) have been widely used recently to prove that they are a well-fitted substitute for traditional fossil fuels. Besides, DC/DC converter-based distributed generations integrated with RESs can compensate for the excessive load demand that the grid for any reason is unable to provide. The reason for choosing DC systems is that available loads are mainly of DC type. However, instability of DC microgrids as a result of negative incremental effect of constant power loads must be considered a crucial challenge in designing such modern power systems. After solving this, the voltage regulation problem must be dealt with using a proper control technique considering the system structure. The designed control system must be able to tackle the available challenges and resolve the impacts of uncertainties and external disturbances. Uncertainties in RESs, uncertain loads, voltage tracking problem, probable faults in the system configuration, etc are considered challenges in the voltage control of DC microgrids that all tried to be resolved and dealt with in this study.