Source: CRRC Zhuzhou Institute

Recently, the “Wind-PV-Storage” Green Low-Carbon Energy Supply Project of Jingjiang Special Steel Co., Ltd., a National Low-Carbon Metallurgy Technology Research Pilot Project invested by Xinli Era under the CITIC Pacific Energy Co., Ltd., was successfully connected to the grid.

As the general contractor for the 120 MW / 240 MWh grid-forming high-voltage direct-connected energy storage system, CRRC Zhuzhou Institute Co., Ltd. applied high-speed rail-grade grid-forming converter technology and system integration expertise to successfully help Jingjiang Special Steel Co., Ltd. create China’s first near-zero-carbon steelmaking demonstration plant, providing an effective model for intelligent, green, and low-carbon transformation in the steel industry.

The project’s completion marks the beginning of a strong partnership between CITIC Pacific Energy and CRRC Zhuzhou Institute in the industrial and commercial energy storage sector.

To meet the project’s fast grid connection requirements, CRRC Zhuzhou, after confirming the technical specifications, completed the full delivery of the 120 MW / 240 MWh grid-forming high-voltage direct-connected energy storage system within 45 days. Working with China Energy Engineering Group Jiangsu Power Design Institute Co., Ltd., they integrated a 36 MW distributed PV system and a 16.8 MW onshore wind power system to provide a comprehensive energy supply. Through the system’s grid-forming energy storage stability and fast-response capability, the project overcame challenges from high-impact steelmaking loads and the strong intermittency of renewable energy, optimizing energy matching in time and space, improving energy coordination efficiency, reducing carbon emissions, and achieving both high-efficiency stable production and green low-carbon goals.

01 Establish a zero-carbon industrial park

Building a resilient microgrid to ensure stable renewable energy supply

Upon completion, it will become China’s first grid-forming wind-PV-storage integrated microgrid demonstration project in the steel industry, expected to provide 75 million kWh of green electricity annually, reducing carbon emissions by 62,400 tons. By coordinating wind, solar, and storage with electric furnace loads, the project offers a full-process energy solution, helping Jingjiang Special Steel build a new green and low-carbon brand.

Focusing on continuous short-process electric furnace production, the project deploys grid-forming energy storage at the park level with three main objectives: stabilize power quality, increase the share of green electricity, and ensure continuous production. The park’s grid is structured to be autonomous, grid-connected, and switchable, transforming green electricity from “uncertain supply” to “stable, controllable, and high-quality supply”.

02 Technical Highlights

Power quality and renewable energy utilization have become key

challenges for zero-carbon industrial parks

teelmaking, as a typical high-load and high-impact process, demands high grid stability and reliability. Addressing the intermittency and fluctuations of renewable energy is key to achieving high-proportion green power supply. The mismatch between PV, wind power, and load limits renewable utilization, while the energy storage’s power and energy regulation capabilities effectively solve this problem. Grid-forming energy storage becomes an indispensable part of high-quality, high-utilization renewable microgrids.

High-voltage direct-connection architecture: breaking the “shackles” of efficiency and cost

The high-voltage direct-connected architecture developed independently by CRRC Zhuzhou uses H-bridge module cascades to synthesize 35 kV on the AC side, eliminating transformers, shortening energy paths, reducing system current and line losses, and enabling system cycle efficiency to exceed 92%, which is 6% higher than conventional low-voltage storage. This also reduces civil and equipment investment, adding about RMB 48 million in revenue over the 240 MWh storage system lifecycle.

Grid-forming energy storage: microgrid stabilizer

Grid-forming energy storage actively generates stable voltage and frequency, effectively combining “stabilizer + independent power supply”. The system provides 3×10-second grid-forming capability, and under high-impact steelmaking load conditions, its direct connection to the grid allows rapid response within 20 ms, providing instantaneous power support and bus voltage stability, ensuring power quality and production continuity.

Performance leap: millisecond-level grid connection/disconnection and 10-second black start

High-voltage cascaded direct-connected grid: shorter electrical distances and greater overload capacity. The system’s single-unit capacity reaches up to 45 MW. In the event of an external grid outage, it can achieve millisecond-level smooth grid connection / disconnection within 100 ms, forming an independent and stable high-voltage microgrid. It also features a 10-second rapid black start, requiring no external grid support, allowing the system to autonomously establish a stable high-voltage microgrid and restore power within seconds, ensuring uninterrupted, loss-free operation of high-load steel production lines.

Integrated source-grid-load-storage platform, unlocking 100% potential of grid-forming energy storage

The integrated source-grid-load-storage platform provides a framework that is observable, measurable, adjustable, and controllable, optimizing charging and discharging strategies based on weather and output forecasts. Local green electricity utilization is increased from below 70% to over 95%, with annual additional green power benefits exceeding RMB 10 million. In abnormal conditions, the platform triggers safety mode for rapid grid-forming switching. Full-state awareness and strategic dispatch of the storage system reduce manual intervention by over 90%, simplifying operations and maintenance.

03 Multiple Benefits and Industry Breakthroughs

Grid-forming energy storage releases multiple values including capacity,

regulation, and power quality

The revenue structure is clear: it can increase green power utilization by 168 million kWh annually, reduce downtime and equipment wear, and generate additional benefits through green power trading and certificates, turning electricity from a cost center into an asset operation.

The next step is to integrate the park into virtual power plants for power market participation, releasing value in capacity, regulation, and power quality in a new-type power system that emphasizes system stability.

The Jingjiang Special Steel model: grid-forming energy storage empowers high-energy-consumption parks for zero-carbon transformation

In the near future, the Jingjiang Special Steel experience will be replicated across more industrial parks to strengthen capabilities in “park autonomy + multi-energy coordination + carbon accounting”. High-energy-consumption parks will be efficiently and reliably served through the “three-piece delivery suite” of standardized hardware combinations, scenario-based control strategies, and park-level dispatch interfaces. With more advanced energy storage system architectures and technologies, power quality and system resilience will be developed into tradable resources. Grid-forming energy storage helps microgrids reduce dependence on the main grid and, through the source–grid–load–storage–carbon coordination, enables dynamic capacity expansion, local autonomy, and high renewable energy utilization, becoming key infrastructure for industrial zero-carbon transformation and power grid modernization.

Pioneer of Grid-Forming Energy Storage: CRRC Zhuzhou Institute’s Experience and Vision

CRRC Zhuzhou Institute has successfully leveraged its extensive expertise in high-voltage converter design, multi-level converter topology development, and over 20 years of engineering experience with high-voltage conversion equipment in the rail transit sector to the energy storage field. This led to the launch of the grid-forming high-voltage direct-connected energy storage system, achieving seamless technological integration from the “heart of rail transit” to the “backbone of energy storage”.

As of September 2025, CRRC Zhuzhou’s grid-forming energy storage systems have reached a cumulative grid-connected capacity of 3 GWh and a contracted capacity of 5 GWh. Landmark projects such as the world’s first high-altitude grid-forming storage station in Ali, Tibet, and China’s first user-side high-voltage cascaded grid-forming storage station in Jingjiang, Jiangsu, have successfully demonstrated the company’s ability to provide highly reliable grid-forming energy storage solutions in extreme environments and complex industrial scenarios.

Looking ahead, CRRC Zhuzhou Institute will continue to advance innovation and application of grid-forming energy storage technologies, contributing more key technologies to drive the energy transition and industrial zero-carbon development.

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