State and disturbance estimation with supertwisting sliding mode control for frequency regulation in hydrogen based...

Area of Science:

• Electrical Engineering
• Control Systems
• Renewable Energy Integration

Background:

• Microgrids require robust control for stable operation with intermittent renewable energy sources (RESs) and energy storage.
• Frequency regulation and tie-line power transfer fluctuations are critical challenges in multi-area power systems.

Purpose of the Study:

• To develop and evaluate an enhanced super-twisting sliding mode control (STSMC) scheme for microgrid frequency regulation.
• To improve disturbance estimation and system performance using hybrid observers and optimization techniques.

Main Methods:

• Incorporation of a hybrid extended state observer (ESO) and higher order sliding mode observer (HOSMO) for state and disturbance estimation.
• Utilizing a puma optimizer (PO) metaheuristics scheme for optimizing area regulator performance.
• Implementing STSMC with a focus on frequency and tie-line power transfer stability.

Main Results:

• Achieved significant reduction in frequency deviations (ΔF) and tie-line power fluctuations (ΔP_tie) within 10^-6 Hz/p.u. ranges.
• Demonstrated substantial peak disturbance overshoot and undershoot reduction (up to 99.771%) compared to other scenarios.
• Validated the enhanced STSMC's robustness, low complexity, and fast convergence in simulations.

Conclusions:

• The enhanced STSMC effectively mitigates frequency fluctuations and tie-line power abnormalities in microgrids.
• The proposed control scheme offers superior performance for integrating RESs and energy storage.
• The hybrid observer and optimization approach enhances disturbance rejection and overall system stability.