Sungrow Supports Large-Scale BESS System in Cambodia with 'Black Start' Feature
Takmao, Cambodia — Sungrow, a leading global provider of PV inverters and energy storage systems, has announced that the Cambodia EDC Kandal Stueng Station (GS7ly) project has successfully connected to the power grid and completed acceptance testing. The Battery Energy Storage System (BESS) project, with a capacity of 108.4 MW/215.6 MWh, is located in Takmao, Kandal Province. The project implements grid-forming technology on a large-scale utility system to support grid stability, black start features, and coordination with hydroelectric and thermal power plants.
Grid-Forming Technology Strengthens Various Grid Recovery Features
The project also maintains voltage and frequency stability at strategic points of Cambodia’s main power grid, including the transmission corridor that supplies electricity from Vietnam. The grid-forming capability of the system was tested through various complex grid recovery scenarios, proving the increasingly vital role of energy storage systems in maintaining the reliability of the electricity system.
Key project achievements include:
Large-scale black start feature from a zero-voltage condition: 516 units of grid-forming PCS successfully activated the entire power plant from a zero-voltage state, establishing stable voltage and frequency across the system.
Recovery of a 240 km transmission network: The system supported the activation of approximately 240 km of the transmission network and five substations, maintaining operational stability as the network was gradually restored.
Support for various power sources: The system supported the startup and synchronisation process of the 60 MW Kamchay Hydroelectric Power Plant, before the restored network operated alongside the 135 MW CIIDG coal-fired power plant, the energy storage system, and the electrical load.
Stable operation under complex grid conditions: During the grid recovery process, the system remained stable through five transformer energisation processes, including transformers with capacities up to 100 MVA. The system also maintained stability when synchronising various power sources with phase angle differences of up to 15 degrees, demonstrating its ability to handle complex conditions during system recovery.
Islanded operation: The system operated independently for 3.5 hours, proving the ability of the energy storage system to continue supporting the local grid when disconnected from the main grid.
Seamless transition: The project successfully performed three transitions between connected and islanded states from the main grid. During these processes, voltage deviation remained below 2%, while transient frequency fluctuations were within the 0.15 Hz range.
“This project demonstrates that energy storage systems with grid-forming technology have a much broader function than merely storing electricity. When the power grid experiences disturbances or loses support from the main grid, this technology helps build and maintain voltage and frequency stability, accelerates system recovery, and maintains grid reliability,” said Michael Rul, Regional Director, Sungrow Southeast Asia and South Asia. “Through projects like this, Sungrow encourages the use of energy storage systems as a more active part of maintaining grid reliability, and provides proven grid-forming technology to support the continuously evolving electricity systems in Southeast Asia.”
Reducing Technical Risks and Ensuring Timely Completion
Facing strict testing protocols, complex power system scenarios, tight construction schedules, and working conditions during the rainy season with ambient temperatures up to 40°C, Sungrow’s cross-functional team—including pre-sales, on-site execution, and R&D—worked together to ensure high-quality project results:
Commissioning and testing phase within 20 days: The on-site project team worked tirelessly in hot and humid conditions for two consecutive months. The team completed hot commissioning and three rounds of performance testing within 20 days to ensure grid connection according to schedule.
Integrated service solutions: Sungrow provides a one-stop service throughout the project life cycle, covering integrated design for storage and monitoring, EPC-related support, equipment design, commissioning, as well as operation and maintenance (O&M) services. These services help customers meet specific grid-level requirements while reducing management burdens.
In line with the accelerating energy transition in Southeast Asia, Sungrow will continue to provide proven energy storage technologies and solutions so that customers can build more reliable and sustainable electricity infrastructure.