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This paper presents a novel and robust hybrid controller that combines the backstepping controller with the nonsingular fast terminal sliding mode controller (NFTSMC) for DC-DC boost converters (DDBCs) operating alongside constant power loads (CPLs). The primary aim of the controller is to enhance the stability of the DC-bus voltage while consistently delivering power to the CPL. To achieve this objective, the exact feedback linearization approach is applied to transform the nonlinear dynamical model of the DDBC into Brunovsky’s canonical forms. The incorporation of matched uncertainties into the dynamical model illustrates the robustness of the proposed control approach. The hybrid controller is formulated based on this model, leveraging Lyapunov stability theory to ensure large signal stability under the designated control law. Significantly, the NFTSMC effectively addresses the singularity problem associated with sliding mode controllers (SMCs). The effectiveness and resilience of the proposed controller are validated under variations in input voltage, reference voltage, and power demand. Comparative analysis is conducted by contrasting simulation results with those obtained using conventional SMC (CSMC) and a typical PI controller (PIC). The results unequivocally highlight the superiority of the proposed controller in terms of ensuring system stability and providing a rapid response across various operating modes. Furthermore, to authenticate the practical applicability of the proposed controller, processor-in-loop (PIL) validation is employed, confirming its effectiveness in real-world scenarios.

This paper presents a robust hybrid super-twisting reaching law-based sliding mode controller in conjunction with a complementing recursive backstepping controller for DC-DC boost converters with constant power loads (CPLs). The key control goal is to keep the DC-bus voltage steady and constant while continuously powering the CPL. The nonlinear dynamical model of the DC-DC boost converter is translated into Brunovsky’s canonical forms, utilizing the precise feedback linearization technique to attain this control goal. It is worth mentioning that the dynamical model has been modified with bounded external uncertainties to demonstrate the restraint performance for huge loads and input voltage variations. The proposed hybrid controller is then constructed using this model. Furthermore, to ensure the large signal stability of the whole system under the designed control law, the Lyapunov stability theory is used. Numerical simulation analysis are carried out in MATLAB/Simulink to validate the performance of the designed robust controller for a DC–DC boost converter feeding a CPL when the operating point change. The results show that the designed controller outperforms both existing nonlinear controllers and a traditional PI controller in terms of ensuring the system’s stability and fast response in a variety of operating modes. Finally, in order to confirm the theoretical design and simulation results of the designed robust hybrid controller, experimental results are also provided in this paper.

In this paper, a composite nonlinear controller is developed for stabilizing a constant power load (CPL) feeding DC-DC boost converter (DBC) for DC microgrid applications. If the boost converter is not properly controlled, the negative incremental impedance (NII) of CPLs can cause DC-bus voltage instability. As the original model is not adequate for designing the proposed controller, the nonlinear dynamical model of the DBC is transformed into Brunovsky’s canonical forms. Large load and input voltage changes hinder the controller’s performance. Therefore, the dynamical model has been updated to include constrained external uncertainty. Then, the proposed hybrid controller, which is a combination of the nonlinear backstepping controller and the sliding mode controller, is designed. The sliding mode controller has a double-integral-based sliding surface and a fast power-based reaching law to improve hybrid controller performance. The global stability of the proposed system is analyzed using the control Lyapunov function theory. Lastly, simulation studies in MATLAB/Simulink and experiments on an in-house hardware platform show that the proposed composite controller works well even when there are big changes.