In the rapidly evolving landscape of renewable energy, the integration of hydrogen as a zero-carbon energy carrier is gaining significant traction. Researchers are increasingly exploring ways to harness hydrogen’s potential to stabilize and sustain modern power grids. A recent study published in the journal Energies, led by Zhengyao Wang from the School of Electrical Engineering and Automation at Harbin Institute of Technology in China, introduces a groundbreaking control method for electric–hydrogen coupling microgrids. This innovative approach promises to revolutionize how we manage and utilize renewable energy sources, particularly in the context of microgrids.
The study focuses on a hybrid AC-DC microgrid that integrates photovoltaic (PV) panels, battery energy storage systems (BESS), electrolysers, hydrogen storage tanks, and fuel cells. The proposed control method employs a hierarchical structure, combining upper-level power management strategies with lower-level converter controls. This dual-layer approach ensures efficient power dispatch and maintains grid stability, whether the microgrid is operating on-grid, off-grid, or transitioning between the two modes.
At the heart of this system is a power management strategy (PMS) that allocates power to each component based on the states of energy storage. “The PMS classifies microgrid operation into 10 distinct statuses according to source–load imbalances along with deviations of SOC and SOHC from their respective boundaries,” explains Wang. This sophisticated strategy ensures that the microgrid can balance source and load, preventing excessive charge or discharge of the hybrid energy storage system (HESS).
The lower level of the control method utilizes a master–slave control strategy. The master converter, regulated by virtual synchronous generator (VSG) control, stabilizes voltage and frequency in off-grid mode and synchronizes with the upstream grid in on-grid mode. The slave converter, on the other hand, follows the master converter under active and reactive power (PQ) control, ensuring seamless operation.
One of the most innovative aspects of this research is the introduction of a pre-synchronisation control strategy. This method eliminates the need for traditional phase-locked loops, which are often prone to accuracy issues. By tracking voltage signals on both sides of the point of common coupling (PCC), the pre-synchronisation strategy ensures a smooth transition from off-grid to on-grid mode, avoiding voltage fluctuations and current shocks.
The implications of this research are far-reaching. As the energy sector continues to shift towards renewable sources, the ability to efficiently manage and store energy becomes crucial. Hydrogen, with its high energy density, offers a promising solution for long-term energy storage. By integrating hydrogen with other energy storage technologies, microgrids can achieve greater stability and reliability, even in the face of fluctuating renewable energy inputs.
“This control method not only enhances the stability of microgrids but also paves the way for more efficient and sustainable energy management,” says Wang. “It represents a significant step forward in the integration of hydrogen into our energy systems.”
The study, published in Energies, demonstrates the potential of this control method through extensive simulations. The results show that the proposed control strategy effectively maintains voltage and frequency stability in various operating modes and scenarios. This research sets the stage for future developments in the field, including semi-physical simulation experiments and field tests using real-world electric–hydrogen coupling microgrids.
As the energy sector continues to evolve, innovations like this will be crucial in shaping a more sustainable and resilient energy future. By leveraging the unique advantages of hydrogen and other renewable energy sources, we can create a more stable and efficient power grid, capable of meeting the demands of a rapidly changing world.
