Transforming Power Grid Operations: Embracing New Technologies for Stability and Efficiency

A New Paradigm for Power Grid Operation

Power grids function like a complex ballet of energy generation and consumption that must remain perfectly balanced at all times. They maintain a steady frequency—60 Hz in North America and 50 Hz in many other regions—by aligning power generation with demand in real-time. Traditional power plants, featuring large rotating turbines and generators, play a vital role in this balance through their mechanical inertia. This inertia, the natural tendency of these massive spinning machines to resist changes in rotational speed, serves as a stabilizer for the grid.

When sudden changes occur in power demand or generation, such as when a large factory turns on or a generator fails, the rotational energy stored in these machines helps cushion the impact. They may momentarily speed up or slow down, providing grid operators with crucial seconds to respond and adjust other power sources.

However, as we shift towards renewable energy sources like solar and wind—which lack mechanical inertia—maintaining grid stability becomes more challenging. Consequently, grid operators are increasingly focusing on technologies such as synthetic inertia from wind turbines, battery storage systems, and advanced control systems to mimic the stabilizing effects that traditional power plants provided.

Alex Boyd, CEO of PSC, a global consulting firm specializing in power systems and control engineering, believes that the importance of inertia will diminish sooner than many anticipate. During his appearance on The POWER Podcast, he suggested that stability based on physical inertia might soon become the least preferred approach. Boyd explained, “The premise behind stability based on inertia is that it makes it difficult for the grid to change quickly, which in turn grants stability.” He continued, “With the evolution of power electronic-based stability services, we will have many more options for precise control and rapid adjustments than we have today.”

Power electronics systems leverage inverter-based resources, such as wind, solar, and batteries. These systems can detect and respond to frequency deviations almost instantaneously, providing faster stabilization compared to mechanical inertia. While they reduce the amount of physical inertia available, they also lessen the inertia required for stability through sophisticated control strategies.

Virtual synchronous generators and advanced inverters can dynamically emulate inertia, offering customizable responses that adapt to grid conditions. For instance, adaptive inertia schemes can provide high initial inertia to absorb faults but decrease it over time to prevent oscillations. Power electronic systems can address stability issues across various frequencies and timescales, including harmonic stability and voltage regulation, through modeling and control techniques that mechanical systems cannot achieve.

These inverter-based resources allow for decentralized coordination of grid services, such as frequency regulation and voltage support, fostering a more distributed grid operation compared to traditional inertia-centric systems. They are essential for grids with high penetration of renewable energy sources, which inherently lack mechanical inertia. These systems ensure stability while facilitating the transition to low-carbon energy by emulating or replacing traditional generator functions.

“I foresee a time in the not-too-distant future when we will design systems that are less dependent on physical inertia because it hinders our progress,” Boyd stated. “That time is approaching, although there will be challenges and much to learn along the way.”

For a deeper dive into Boyd’s insights, including predictions about renewable system designs, future utility revenue models, and the urgency of addressing carbon reductions, listen to The POWER Podcast. Click on the SoundCloud player below to listen in your browser now, or use the following links to reach the show on your preferred podcast platform: Apple Podcasts, Spotify, YouTube, YouTube Music, Amazon Music, iHeart, TuneIn, SoundCloud.

—Aaron Larson is POWER’s executive editor (@AaronL_Power, @POWERmagazine).