#Germany #Huawei #Munich #LUTERRA #ESS Platform

Unveiling Huawei's Next-Gen Smart String Grid-Forming ESS Platform LUTERRA

In a significant announcement at Intersolar Europe held last month in Germany, Huawei introduced its groundbreaking Smart String Grid-Forming Energy Storage Solution (ESS) Platform, LUTERRA. This advanced platform, designed by Huawei Digital Power, is the result of technological innovations aimed at bolstering customer success in the realm of renewable energy.

Steve Zheng, the President of the Smart ESS Business at Huawei Digital Power, elaborated on how Huawei has achieved industry-leading efficiency in the installation of battery storage solutions that offer grid-forming (GFM) applications at the facility level.

Huawei's GFM technology has already proven its effectiveness in real-world conditions, notably exemplified by the largest 100% renewable energy microgrid located at a Red Sea resort in Saudi Arabia. This project, which has been operating steadily for over two years, demonstrates the feasibility of coordinating GFM energy sources across multiple facilities at a gigawatt-hour scale.

While large projects, such as the 400 MW solar PV system paired with a 1.3 GWh battery energy storage system (BESS) in Saudi Arabia, are few and far between, Huawei's technology promises increased revenue, greater efficiency, and seamless integration with solar energy systems for clients of all sizes.

Zheng attributes the unique features of the system—including round-trip efficiency (RTE), high-precision state of charge (SOC) control, and optimization from cell to pack—to the confluence of various disciplines, including electrochemistry, electrical engineering, and control technology. He highlights that, due to Huawei's comprehensive oversight of the overall solution, their system achieves a remarkable 93.1% efficiency on the low-voltage side of the power conversion system (PCS) under ambient temperatures of 25 °C, with SOC accuracy reaching ±2.5% at both ends and ±3% in the plateau region.

The LUTERRA solution boasts an integrated design featuring comprehensive thermal management from cell to pack, liquid cooling systems, and a high-voltage silicon carbide (SiC) switching architecture. This configuration presents unique performance advantages for long-duration energy storage (LDES) applications compared to competitors. Zheng explains, “We maintain the string architecture, utilizing an optimizer for each pack and a controller for each rack. These advanced management methodologies eliminate electrochemical inconsistencies, particularly those that arise over the lifespan of the battery.”

One pivotal enhancement in this next-gen solution is the step-up of AC voltage to 1000 V, a first realized through SiC components. This adjustment not only minimizes system losses but also augments overall efficiency. Moreover, unique intelligent and distributed cooling technologies broaden the heat distribution area, leading to improvements in RTE, consistency, SOC levels, and overall availability, enhancing performance by over 10% compared to conventional solutions.

Despite the advanced nature of the technology, Zheng assures that the setup and logistics processes have been simplified to the greatest extent possible. In a hypothetical example of a BESS facility with a capacity of 1 GWh, the LUTERRA platform can deliver the system in at least 30% less time compared to traditional solutions and reduces costs associated with the rest of the balance of plant (BOP) by at least 20%. Furthermore, it minimizes the footprint per megawatt-hour installed by one square meter. Zheng attributes these outcomes to Huawei's patented “through-busbar” architecture, which offers flexible installation, capacity scaling, and adaptable C-rates for charging and discharging throughout the project lifecycle.

As readers of Energy-Storage.news might be aware, grid-forming technologies and their associated applications have gained significant importance in enhancing electrical grid stability globally. Historically, grid frequency and voltage have been largely determined by the rotating mass of thermal energy production turbines. However, as variable renewable energy (VRE) sources increasingly replace fossil fuel-dependent assets, new challenges in maintaining system stability have arisen.

Fortunately, GFM-capable inverters can deliver the same inertia values, short circuit current ratio (SCR), and black-start capabilities essential for stabilizing the grid. GFM has emerged as an ideal solution for BESS across regions like the UK, Australia, and China, which are actively incorporating grid-forming resources.

In Europe, four transmission system operators (TSOs) in Germany launched a long-term inertia service market that includes GFM BESS assets earlier this year, while the European Network of Transmission System Operators for Electricity (ENTSO-E) is preparing technical guidelines concerning grid-forming requirements across 36 countries.

Zheng states, “Grid-forming technology is vital for maintaining the stability of an electric grid with a high share of renewable energy. This technology has evolved from individual equipment to strings and energy plants.” Huawei has identified six characteristics essential to grid-forming: inertia, short circuit ratio, primary frequency regulation, damping of power oscillations, black start initiation, and transitioning to islanding mode in Virtual Synchronous Generator (VSG) mode.

Zheng strongly believes that advancements in facility-level grid-forming technology are crucial. A 100 MW BESS facility will consist of thousands of power electronics devices functioning in GFM mode. “Facilitating the harmonious operation of these devices, which must work together to stabilize the grid, is a complex technical challenge,” he notes, citing the Red Sea project as a case study.

Huawei's innovative technology has also been applied in large-scale grid-forming projects across various countries, including Germany, Bulgaria, the Philippines, and China.

The company’s product roadmap focuses on optimization at both the string and system levels. Huawei aims to develop the industry’s largest GFM energy storage solution optimized for balance of plant (BOP) considerations at the system level. The rationale behind this roadmap selection is to concentrate not merely on the power and energy density of a single BESS container but rather the power and energy density of an entire string or energy plant. “When the string solution is optimal, the entire facility becomes optimal. A single container does not constitute an energy storage system; cells alone do not create an energy storage system,” explains Zheng.

Hence, in our design and planning, we evaluate each string as a fundamental unit rather than blindly attempting to increase the power density of a single container. The Smart String ESS Platform features a design incorporating a two-stage 1000 Vac high-voltage architecture. This grid-forming storage system can address critical “front-of-meter” operational challenges faced by utility-owned renewable energy plants and commercial and industrial (C&I) storage applications, even as energy storage assets face increasingly stringent grid support requirements.

“Architecturally, we believe that the two-stage solution offers superior grid security compared to traditional single-stage solutions,” Zheng concludes. In high-voltage continuous operation (HVRT) conditions, sudden current will flow between the electrical grid and PCS. Particularly when the state of charge (SOC) is low, this might lead to insulation failure of the battery and serious safety issues. Moreover, during low-voltage ride-through (LVRT) conditions, a specific steady active power is required to help rapidly restore the electrical grid. “These advantages are not present in single-stage architectures.”