Adaptive Output Voltage Regulation for DC–DC Converters Under Nonideal Load Conditions: A Current-Constrained Fixed-Time Control Approach

TY - JOUR

T1 - Adaptive Output Voltage Regulation for DC–DC Converters Under Nonideal Load Conditions

T2 - A Current-Constrained Fixed-Time Control Approach

AU - Song, Guangyu

AU - Liu, Xinghua

AU - Zhang, Chuanlin

AU - Xiao, Gaoxi

AU - Wei, Zhongbao

AU - Yang, Jun

N1 - Publisher Copyright: © 1986-2012 IEEE.

PY - 2026/4

Y1 - 2026/4

N2 - In this article, a composite current-constrained fixed-time control approach is proposed based on the adaptive fixed-time disturbance observer (AFTDO) for dc–dc converters of hybrid energy storage systems (HESS) to regulate the bus voltage so that its desired reference is tracked within a fixed time. As mismatched disturbances can severely impact the system control effect, AFTDO is designed to provide the disturbance estimation and mitigate parameter uncertainties and load disturbances, which accelerates the estimation rate and enhances system robustness. A current-constrained fixed-time controller is then proposed to regulate the duty ratio such that the HESS possesses fixed-time convergence and achieves desired voltage tracking within a fixed time independent of initial states, where a current constraint gain is developed to strictly guarantee overcurrent protection. Moreover, a fixed-time load estimator is presented to enhance system robustness against external unknown loads. The closed-loop HESS fixed-time stability is rigorously proven based on the Lyapunov theory. A 420-V/3-kW scaled-down hardware platform is implemented to validate the proposed controller. Simulation and experimental results demonstrate the feasibility and superiority of the proposed approach under various fluctuating conditions.

AB - In this article, a composite current-constrained fixed-time control approach is proposed based on the adaptive fixed-time disturbance observer (AFTDO) for dc–dc converters of hybrid energy storage systems (HESS) to regulate the bus voltage so that its desired reference is tracked within a fixed time. As mismatched disturbances can severely impact the system control effect, AFTDO is designed to provide the disturbance estimation and mitigate parameter uncertainties and load disturbances, which accelerates the estimation rate and enhances system robustness. A current-constrained fixed-time controller is then proposed to regulate the duty ratio such that the HESS possesses fixed-time convergence and achieves desired voltage tracking within a fixed time independent of initial states, where a current constraint gain is developed to strictly guarantee overcurrent protection. Moreover, a fixed-time load estimator is presented to enhance system robustness against external unknown loads. The closed-loop HESS fixed-time stability is rigorously proven based on the Lyapunov theory. A 420-V/3-kW scaled-down hardware platform is implemented to validate the proposed controller. Simulation and experimental results demonstrate the feasibility and superiority of the proposed approach under various fluctuating conditions.

KW - Current constraint (CC)

KW - dc–dc converters

KW - disturbance observer

KW - fixed-time control

KW - nonideal load condition

UR - https://www.scopus.com/pages/publications/105021953682

U2 - 10.1109/TPEL.2025.3632384

DO - 10.1109/TPEL.2025.3632384

M3 - Article

AN - SCOPUS:105021953682

SN - 0885-8993

VL - 41

SP - 5602

EP - 5618

JO - IEEE Transactions on Power Electronics

JF - IEEE Transactions on Power Electronics

IS - 4

ER -