Robust H∞ control for master-slave power converters in renewable energy systems

• Proposes a robust H-infinity controller for master-slave power converters to ensure reliable synchronization in renewable energy systems. • Presents the complete mathematical model of the master-slave converter system, including stability and robustness criteria. • Investigates system performance and stability under parameter variations and external disturbances. • Validates the designed controller’s efficiency through rigorous time-domain and frequency-domain analyses. • Achieves improved stability and power quality via simulations under diverse operating scenarios. This paper proposes a robust H∞ control technique to enhance the stability and performance of master-slave power converters in renewable energy systems. The microgrid's parameters often vary continuously due to the changes in generation patterns, load fluctuations, and grid impedance uncertainties. The proposed method presents a mathematical analysis and derivation of the H∞ controller for the master-slave converters that can face the parameter uncertainty and external disturbances. The detailed modeling and simulation of the system were illustrated and validated using the MATLAB toolbox and SIMULINK. The simulation results show that the designed H∞ controller outperforms conventional PI control in all tested scenarios in terms of time and frequency responses. Compared to the PI controller, the proposed controller shows superior dynamic performance by reducing the rise and settling times by about 60 % and 80 %, respectively, with the absence of overshoot and undershoot. Besides, the disturbance rejection performance shows an enhancement in transient time, settling time, and peak deviation by about 56 %, 55 %, and 66 %, respectively. Notably, while the H∞ controller improves power control, its effectiveness in voltage regulation is limited across various operating modes, where the voltage profile varies by about ±6 % from its nominal value, except in the voltage restorer mode, where the voltage can be controlled precisely.