The Technological Breakthroughs Behind Huawei's New Generation Smart String Grid-Forming ESS Platform

Huawei launched LUTERRA at the Intersolar Europe event in Germany last month. According to Steve Zheng, President of Smart ESS Business at Huawei Digital Power, the company has delivered a battery energy storage solution that is easy to install, boasts industry-leading efficiency, and supports grid-forming (GFM) applications at the power plant level. Huawei’s grid-forming technology has been proven through various field implementations, including the world’s largest 100% renewable energy microgrid located in The Red Sea tourist area in Saudi Arabia. Having operated stably for more than two years, this project demonstrates that the coordination of grid-forming energy resources across multiple sites can be applied at the gigawatt-hour scale. Although few projects match the scale of The Red Sea facility—which features a 400 MW solar power plant and a 1.3 GWh Battery Energy Storage System (BESS)—Huawei’s technology still helps customers increase revenue, throughput, and achieve more optimal integration with solar plants. According to Zheng, advantages such as industry-leading round-trip efficiency (RTE), high-precision state of charge (SOC) control, and cell-to-pack optimisation are achieved through a combination of disciplines, ranging from electrochemistry, electrical engineering, and electronics to thermodynamics, control technology, and predictive technology. “Huawei controls all aspects of the solution comprehensively, enabling it to achieve 91.3% efficiency on the low-voltage side of the PCS at an ambient temperature of 25°C. Furthermore, SOC accuracy reaches 2.5% at both ends of the operational range and 3% in the plateau area,” Zheng stated. The integrated design encompasses comprehensive thermal management from the cell level to the battery pack, a liquid cooling system, and a high-voltage silicon carbide (SiC) switching architecture. This combination provides a distinct advantage for Long-Duration Energy Storage (LDES) applications compared to other products available on the market. “We maintain the string architecture and apply an optimizer to each battery pack and a controller to each rack. This detailed and effective approach can overcome electrochemical inconsistencies, including characteristic differences that emerge throughout the battery life cycle,” Zheng explained. He added, “Huawei’s latest generation solution increases the AC voltage to 1000V AC for the first time by utilising SiC components. This step also reduces energy loss and improves system efficiency. The intelligent distributed cooling technology increases the heat dissipation area. On the other hand, the combination of RTE, consistency, SOC level, and high system availability can improve throughput by more than 10% compared to conventional solutions.” Despite incorporating complex technology, Huawei designed the installation and logistics process to remain simple. In a 1 GWh BESS project example, the LUTERRA Smart String Grid-Forming ESS Platform can cut delivery time by at least 30%, lower balance of plant (BOP) costs by a minimum of 20%, and reduce land requirements by one square metre for each megawatt-hour of installed capacity compared to conventional solutions. According to Zheng, this achievement is supported by Huawei’s patented Through-Busbar architecture. This technology supports a more flexible installation process, easier capacity expansion, and C-rate adjustments for the charging and discharging process throughout the project’s life cycle. Grid-forming technology is playing an increasingly important role in maintaining power system stability in various countries, especially with the growing utilisation of renewable energy. Historically, the frequency and voltage of the power system were largely formed by the rotation of thermal power plant turbines. However, as fossil fuel-based generation begins to be replaced or becomes less dominant compared to Variable Renewable Energy (VRE) sources, new challenges arise in maintaining system stability. Inverters with grid-forming capabilities can provide similar functions, including inertia, short-circuit ratio (SCR), and black start features. Therefore, GFM technology is considered highly suitable for application in BESS. Countries such as the United Kingdom, Australia, and China are also beginning to develop grid-forming-based resources. In Europe, four German transmission system operators (TSOs) launched a long-term inertia services market earlier this year that can be participated in by GFM-based BESS assets. Meanwhile, ENTSO-E, representing transmission system operators from 36 European countries, has drafted technical guidelines on grid-forming standards. “Grid-forming technology is key to maintaining the stability of power grids integrating a large share of renewable energy. This technology has evolved from the individual equipment level to array systems and up to power plants,” said Zheng. Huawei defines six main features of grid-forming: inertia, short-circuit level, primary frequency regulation, power oscillation damping, black start, and on/off-grid switching in virtual synchronous generator (VSG) mode. “We believe that the technological breakthrough of grid-forming at the power plant level is a very important factor,” he continued. In a 100 MW BESS installation, for instance, thousands of power electronic devices must operate in GFM mode simultaneously, ensuring all these devices can work in harmony.