A fix for sustainable micropower 

Damaged electronics, overheated motors, and even brownouts or blackouts caused by frequency fluctuations are more common in power grids that rely on renewable energy. The challenge is even greater for microgrids; the small self-contained electricity systems that are increasingly used in remote communities or critical facilities such as residential and commercial hubs. 

As part of the strategic research direction in integrated advanced control of microgrids incorporating energy storage systems, Prof. Ahmed Al-Durra, Associate Provost for Research at Khalifa University has played a transformative role in shaping the future of resilient and intelligent energy systems. Under his leadership, this research direction has bridged the gap between theoretical innovation and real-world implementation by producing high-impact solutions that are both academically distinguished and industrially deployable, including a new model for maintaining the stability of these microgrids. 

“This allows all virtual synchronous generators in the microgrid to automatically share the load without a central control system—like an orchestra playing in tune without a conductor.” 

Prof. Ahmed Al-Durra 

Stability is less of an issue in conventional electricity systems. That’s in part because the spinning parts of traditional generators, such as those in coal or gas plants, provide inertia that naturally resists rapid shifts in electricity demand. This resistance helps keep grid frequency steady at 50 or 60 hertz. But inverters, the devices that convert direct current from solar panels, wind turbines or batteries into alternating current for the grid, lack this capability.  

The solution builds on the concept of virtual synchronous generators (VSGs). These algorithms give inverters virtual inertia, enabling them to respond like traditional generators. If grid frequency drops, they inject extra power; if it rises, they absorb power. 

However, when these VSGs operate independently, their frequencies can drift slightly. Traditionally, in larger power grids, centralized control systems have been used to monitor the entire network and coordinate generators to maintain stable frequency. As renewable and distributed energy sources become more common, these centralized systems are increasingly strained by communication delays and data bottlenecks. 

The Khalifa University team’s system takes a different approach. It adds a decentralized controller to each inverter’s VSG. The controller reacts to past errors, such as a frequency that is too high or low, and prepares for expected changes. This helps the system to stay stable. At the same time, a two-stage filtering mechanism adds another layer of control. First, it smooths fluctuations in local frequency signals, ensuring the controller does not overreact to short-term disturbances. Then it looks at power generation cost to ensure efficient power production. No central or distributed computers are needed, making the system simpler, cheaper and more secure. 

“Each VSG becomes smarter. It monitors its local frequency and adjusts its power output based on how the frequency is behaving, while also accounting for the cost of producing that power,” says Prof. Al-Durra.  

“This allows all VSGs in the microgrid to automatically share the load without a central control system like an orchestra playing in tune without a conductor,” he explains.  

When the team tested their model on a virtual microgrid, it maintained a stable frequency during sudden load changes, power line disconnections or generator failures. “The result is a system that’s stable, scalable, and secure, even under demanding conditions,” says Prof. Al-Durra. 

Reference

Sati, S.E., Al-Durra, A., Zeineldin H.H., El-Fouly, T.H.M. & El-Saadany, E.F. Two-stage filtration for decentralized frequency regulation and stability improvement in economically dispatched virtual synchronous generators within islanded microgrid. Energy 331, 136878, 2025 | Article