To address the issue of AC-side voltage and current imbalance caused by unbalanced loads in islanded hybrid AC/DC microgrids
a negative-sequence voltage suppression strategy based on the generalized super-twisting sliding mode control is proposed
and a load unbalance compensator is introduced. First
a mathematical model of the interlinking converter under unbalanced loads is established in the synchronous rotating coordinate system
and negative-sequence voltage compensation commands are obtained through unbalanced voltage compensation control. Second
based on the traditional super-twisting algorithm
a generalized super-twisting algorithm is constructed by replacing the discontinuous term in its integral part with a continuous fractional-order power term and adding a linear correction term. Using this algorithm
a voltage and current dual closed-loop generalized super-twisting sliding mode controller is designed. Meanwhile
a load unbalance compensator based on a voltage source inverter is adopted to compensate for unbalanced currents. Finally
a simulation model is built in MATLAB/Simulink
and comparisons are made with traditional PI control and first-order sliding mode control. The results show that the proposed strategy effectively suppresses voltage and current imbalance and exhibits excellent dynamic performance under load sudden changes and nonlinear load conditions.
NAJAFZADEH M,AHMADIAHANGAR R,HUSEV O,et al. Recent contributions,future prospects and limitations of interlinking converter control in hybrid AC /DC microgrids[J ] . IEEE Access,2021,9:7960-7984.
YANG C,ZHENG T,SONG Y,et al. Coordinated control strategy of hybrid ac /dc microgrid for power quality improvement under unbalanced ac conditions[J ] . IEEE Transactions on Smart Grid,2021,16(2):837-849.
BUDIWICAKSANA L A,ARDRIANI T,FURQANI J,et al,Improving inverter output current controller under unbalanced conditions by using virtual impedance[J ] . IEEE Access,2021,9:162359-162369 .
ZHUANG Z,LI Y,HU S,et al. A Novel Voltage Compensation Method for VSG in Islanded Microgrids under Unbalanced Load Conditions [C ] //2025 IEEE 8th International Electrical and Energy Conference (CIEEC),Changsha,China,2025:1971-1976.
WANG Y,ZHOU G,LI X. A voltage unbalance compensation strategy based on virtual impedance for DGs in island microgrid without sequence component separation [J ] . International Journal of Ele ctrical Power & Energy Systems,2021,127:106641.
BAYHAN S,KOMURCUGIL H,Sliding-Mode control strategy for three-phase three-level T-type rectifiers with DC capacitor voltage balancing[J ] . IEEE Access,2020,8:64555-64564 .
MEI K,DING S,YU X. A Generalized Supertwisting Algorithm [J ] . IEEE Transactions on Cybernetics,2023,53(6):3951-3960.
MORENOJ A,OSORIOM. A Lyapunov approach to second-order sliding mode controllers and observers [C ] //Proceedings of the 47th IEEE Conference on Decision and Control. Cancun,Mexico,2008:2856-2861.
KIM G,HWANG C,JEON J,et al. A novel three-phase four-leg inverter based load unbalance compensator for stand-alone microgrid [J ] . Electrical Power & Energy Systems,2015,65:70-75.