According to a report from the International Energy Agency (IEA), solar PV has created a record of attracting USD 480 billion in spending in 2023–more than all other power generation technologies combined–while investment in coal power has fallen by 40% since 2021. Obviously, the penetration of renewable energy into the power system is significantly increasing. However, renewable energy does not have the rotation inertia and damping characteristics of traditional synchronous generator rotors. Its anti-interference, overload capacity, frequency and voltage regulation are insufficient, meaning that the continuous rise of new energy power will bring wide frequency oscillation, low inertia, high volatility, weak support and a series of outstanding problems to the grid.
Given that conventional ‘fixing’ methods are no longer sufficient to address the issue, a new energy storage technology solution has emerged, which utilizes energy storage inverters as a platform and focuses on grid-forming control to build synchronous power sources, providing the grid with inertia and voltage support.
Principle of Grid-Forming Energy Storage
Grid-forming energy storage is a solution to address the safety and stability issues arising from the “dual high” trends in the power system. The “dual high” refers to a high proportion of renewable energy and a high proportion of power electronic devices, which increases the difficulty of system regulation and raises the requirements for active support from power sources. This technology utilizes virtual synchronous generator technology to strengthen the grid by replicating the behaviour and performance of synchronous motors. It enables rapid frequency and voltage regulation, increases inertia and short-circuit capacity, and suppresses wide-frequency oscillations. It can operate in both on-grid and off-grid modes.
Technical Barriers and Challenges
Globally, grid-forming energy storage is considered as a cutting-edge technology with high technical barriers. Currently, only a few energy storage manufacturers possess the technical capability for grid-forming energy storage.
Firstly, grid forming requires a control technology for electronic power devices. Compared to grid-following energy storage, grid-forming energy storage requires changes to the fundamental control framework and needs to enhance self-adaptive capabilities in scenarios involving grid disturbances. This necessitates manufacturers to have a solid development capability in power electronics technology. Secondly, grid forming requires a system control technology at the station level, which challenges manufacturers’ software and system control analysis capabilities. Thirdly, a deep understanding of the operating mechanisms of power systems is required, which demands that energy storage companies have practical cases and accumulated experience.
Kehua’s Technological and Practical Accumulation
Unlike other fields, if energy storage manufacturers lack the aforementioned technical capabilities, it is extremely difficult to develop high-performance, high-reliability grid-forming energy storage system solutions in a short period. As a global leader in ESS solutions, Kehua has continuously focused on the power electronics field for 36 years and has accumulated over a decade of experience in micro-grids and energy storage, particularly maintaining a leading market share in the energy storage PCS sector for several consecutive years. Its technical foundation, solid technological innovation, reliable product quality, and practical experience in providing diversified solutions across various application scenarios have enabled Kehua to accumulate extensive knowledge and expertise in grid-forming foundational technology, practical applications, and grid support.
Kehua can be considered one of the earliest companies to engage in the research, development, and practical implementation of grid-forming energy storage. As early as 2018, Kehua began researching virtual synchronous generator control strategies for energy storage systems and achieved grid connection in voltage source mode for energy storage inverters within the same year.
In 2019, Kehua constructed a micro-grid project in Micronesia using a photovoltaic + energy storage + diesel direct current bus topology solution, validating the grid-forming technical performance of the company’s energy storage products.

In 2020, Kehua innovated a grid-forming VSG parallel technology to provide power support for energy storage inverters and achieved seamless independent load switching in an energy storage exploration project in an oilfield in western China, successfully supporting impulse loads.
In 2021, Kehua’s PCS, utilizing grid-forming control technology, assisted in achieving China’s first grid-forming black-start for the 9E series gas power generation unit, the project serving for a Shenzhen Thermal Power Plant. All PCS on-site completed two synchronous phase adjustments and voltage regulation under load conditions in voltage source mode, achieving seamless switching between two different buses in a single start.
In 2022, Kehua provided a grid-forming micro-grid solution for the power department of a Middle Eastern oil ministry, employing grid-forming energy storage combined with photovoltaic inverters and diesel generators, tailored to the characteristics of a weak grid.
In 2023, Kehua took the lead in applying grid-forming energy storage technology in a hundred MW-level energy storage project, enhancing the system’s interference resistance and active support capabilities. By the end of the year, Kehua had secured the bid for the world’s largest grid-forming energy storage project—a 300MW/1200MWh grid-forming energy storage project in Northwest China.

In 2024, Kehua’s energy storage PCS became the first device to pass comprehensive grid-forming energy storage grid connection performance testing by the China Electric Power Research Institute and the first device to receive certification for grid-forming energy storage inverters from CQC, establishing itself as a true leader in grid-forming technology.
Kehua’s grid-forming energy storage technology has demonstrated its practicality and advancement with multiple worldwide projects. The experience from each project feeds back into the company’s design capabilities for grid-forming energy storage technology, helping it to create higher-value solutions for its customers and accelerate the comprehensive application of the technology.
Reference
[1] International Energy Agency, “World Energy Investment 2024,” 2024. [Online]. Available: https://www.iea.org/reports/world-energy-investment-2024. [Accessed: Aug. 19, 2024].