In the quest for stable, renewable energy systems, a team of researchers from China Three Gorges University has developed a groundbreaking control strategy for off-grid wind-solar-hydrogen energy storage systems. Led by Jiangzhou Cheng, the team’s innovative approach promises to revolutionize the stability and efficiency of DC microgrids, paving the way for more reliable and sustainable energy solutions.
The research, published in Energies, focuses on a 10 kV off-grid wind-solar-hydrogen energy storage system. The team’s coordinated control strategy addresses the significant power fluctuations and voltage stability challenges inherent in high-renewable energy systems. By integrating hybrid energy storage and controllable loads, the researchers have significantly improved the system’s ability to handle transient impact events and reduce voltage fluctuations.
At the heart of the system is an enhanced DC/DC converter control scheme. Traditional dual-loop controls have long been the standard, but they struggle with rapid load changes and power supply variations. Cheng and his team improved this by incorporating an extended state observer with adaptive backstepping control. This combination allows the system to dynamically adjust to changes, providing a more stable and robust performance.
“Our approach not only reduces the bus voltage fluctuation range by 24.07% but also decreases the stabilization time by 56.92%,” Cheng explained. “This means the system can respond more quickly to disturbances, making it ideal for applications that require high reliability and stability.”
On the load demand side, the team introduced an electric spring incorporating adaptive fuzzy control. This innovative component adjusts and compensates for voltage fluctuations, ensuring a more stable DC bus voltage. The electric spring’s ability to modulate the bus voltage through the coordinated control of electrolyzer power consumption and terminal voltage is a significant advancement in the field.
The practical implications of this research are vast. For industries such as steel and chemicals, which require high-energy consumption and reliable power supply, this technology offers a viable hydrogen-based power solution. The enhanced stability and reduced voltage fluctuations can extend the lifespan of equipment, decreasing maintenance costs and improving overall efficiency.
Moreover, the system’s rapid response characteristic is particularly beneficial for electric vehicle fast-charging stations. The ability to match sudden power demand changes can support the growing infrastructure needs of the transportation sector, making it a key technological advancement for the future.
The research also highlights the potential for integrating this control strategy into multi-terminal high-voltage direct current (HVDC) grids. Offshore wind power-to-hydrogen systems and industrial complexes with high power supply quality requirements could significantly benefit from this technology, ensuring more stable and reliable energy distribution.
Looking ahead, the team plans to validate the computational efficiency of their control algorithm on a 10 kV/1 MW physical test platform. They will also assess the long-term stability of the system, considering factors such as component aging and environmental variations. Integration with real-time monitoring systems and a comprehensive economic and environmental impact assessment are also on the horizon.
As the energy sector continues to evolve, innovations like Cheng’s coordinated control strategy will play a crucial role in shaping a more sustainable and reliable energy future. By addressing the challenges of renewable energy integration, this research opens new avenues for stable, efficient, and environmentally friendly energy systems. The findings, published in Energies, mark a significant step forward in the quest for carbon neutrality and a more resilient energy infrastructure.
