Introduction

As a pioneer in full-scenario grid-forming energy storage technology, Kehua Digital Energy began its exploration into microgrid projects as early as 2008. It not only possesses successful practical experience from one of China's earliest state-owned microgrid projects but has also extended its microgrid control technology globally, achieving major breakthroughs in black-start technology, laying a solid foundation for grid-forming. In recent years, Kehua has taken the lead in completing all required grid-forming energy storage grid-connection tests and has successively delivered multiple hundred-megawatt-scale grid-forming energy storage projects. Based on 38 years of accumulated expertise in power electronics and extensive project experience, Kehua will launch a series of articles on grid-forming technology, hoping to jointly promote the high-quality development of grid-forming energy storage technology.

As renewables claim a larger share of our energy mix, what new challenges will our power grids face? Our grids, historically reliant on predictable thermal and hydro generation, must now integrate vast amounts of variable wind and solar power. This transition is stressing the system, introducing complexity and instability. Grid-forming technology provides the crucial solution to stabilize this new energy landscape. Here, we explore its origins and global standing.

Understanding Why Power Grids Need Grid-Forming Technology

To grasp the value of grid-forming, we must first examine the challenges modern power systems face. With the dramatic increase in wind and solar installations, grids now face the double-high challenge—high penetration of renewable energy and a high proportion of power-electronic interfaces. This creates several critical issues, as demonstrated by real-world examples:

- Several wind power bases have experienced repeated broadband oscillations—essentially, electrical current fluctuating like water waves. In severe cases, this can force numerous turbines offline and even affect residential electricity supply.

- As more renewables connect, the system's inertia diminishes. Grid frequency becomes more susceptible to exceeding safety limits, creating higher risks during peak demand periods.

- Remote areas with inherently weak grids face greater voltage instability when integrating renewables, sometimes severe enough to damage generation equipment.

The root cause lies in the fundamentally passive nature of traditional renewable energy equipment—they follow grid conditions without contributing to stability. When voltage or frequency fluctuates, they cannot provide support and may even exacerbate problems. This is where grid-forming technology becomes essential.

Demystifying Grid-Forming: The Analogy

The industry defines "grid-forming" as enabling renewable energy assets to autonomously establish and maintain grid voltage and frequency – much like traditional generators do. This represents a fundamental shift from passive grid-following to active grid-supporting operation.

Think of it this way:

Traditional renewable plants act like tenants in the grid. They draw power or generate electricity but take no responsibility for overall building maintenance. In contrast, a grid-forming energy storage system functions as the landlord–not only managing its own power but actively maintaining voltage and frequency stability, even supporting neighbors during grid disturbances.

A critical metric here is the Short-Circuit Ratio (SCR)–the measure of grid strength. Imagine the grid as a vessel and renewables as its cargo:

- High SCR (e.g., SCR=5) resembles an aircraft carrier carrying light cargo–remaining stable even in rough seas

- Low SCR (e.g., SCR=2) is like a fully loaded freighter–requiring careful navigation in turbulent conditions

- SCR≈1 compares to a canoe carrying its own weight–where any shift risks instability

With many renewable bases connecting to relatively weak grids (typically SCR < 2.0), grid-forming technology becomes essential for maintaining system stability.

Global Grid-Forming Technology Landscape: Comparative Analysis

Grid-forming technology development shows significant regional variations in drivers and technical approaches. The comparison below highlights key differences:

Different countries have adopted distinct technological pathways for grid-forming based on their specific needs. In developed economies like the European Union, grid upgrades focus on distributed energy integration and digital transformation, primarily through expanding distribution networks to support distributed sources like rooftop PV and small-scale wind power. Germany is promoting the widespread adoption of grid-forming energy storage through its System Stability Roadmap, requiring grid equipment to possess active support capabilities. The UK utilizes virtual power plants to integrate 160,000 electric vehicles and home energy storage systems for dispatch, achieving flexible demand-side regulation. Australia holds first-mover advantage in grid-forming energy storage, with penetration already reaching 23%. Its eight ARENA-funded projects will significantly enhance grid inertia support capacity.

Meanwhile, developing regions across Latin America, the Middle East, and Southeast Asia face dual challenges of rapid energy transition and weak grid infrastructure. For instance, Saudi Arabia's NEOM new city relies entirely on renewable energy, requiring 100% grid-forming energy storage to maintain grid stability. Brazil's Northeast UHV project uses Chinese technology to deliver clean energy from the north over 1,400 kilometers to load centers. These regions share an urgent need for both long-distance transmission (like UHV) and grid-forming energy storage, with technological pathways closely resembling China's early development stage.

In essence, international approaches either rely on "digitalization + market mechanisms" (developed economies) or "technology transfer + infrastructure development" (developing nations), while China's model of "UHV + policy-driven initiatives" is rapidly deploying grid-forming technology at scale.

When you hear terms like grid-forming or virtual synchronous generator, recognize they represent the grid's stabilizer, renewable energy's ideal partner, and the guardian of power security. As equipment costs decline and standards mature, grid-forming technology will likely become as standard in power grids as transformers are today, supporting our transition toward cleaner, more reliable electricity and bringing us closer to achieving dual carbon goals.