EXECUTIVE SUMMARY
Cambodia’s EDC Kandal Stueng station (GS79) has completed grid connection and full acceptance testing, using Sungrow’s grid-forming technology to provide black-start and grid-restoration capabilities. The 108.4 MW/215.6 MWh BESS demonstrated 3.5 hours of islanded operation and supported restoration of around 240 km of transmission lines.
Capacity: 108.4 MW/215.6 MWh
Location: Takmao, Kandal Province, Cambodia
Status: Grid connected; full acceptance testing completed
PCS: 516 grid-forming PCS units
Transmission restoration: Around 240 km and five substations
Hydropower support: 60 MW Kamchay Hydropower Plant
Thermal generation: 135 MW CIIDG coal-fired power plant
Islanded operation: 3.5 hours
Sungrow, a global provider of PV inverters and energy storage systems (ESS), has announced the successful grid connection and full acceptance testing of the 108.4 MW/215.6 MWh Cambodia EDC Kandal Stueng station (GS79) BESS in Takmao, Kandal Province. The project uses grid-forming technology to support voltage and frequency stability, black-start capability and coordination with hydro and thermal generation at a key point in Cambodia’s central power grid, including transmission corridors importing electricity from Vietnam.
During testing, 516 grid-forming PCS units energized the entire plant from zero voltage and established stable voltage and frequency. The system then supported energization of approximately 240 km of transmission lines and five substations as the network was progressively restored.
The BESS supported the start-up and synchronization of the 60 MW Kamchay Hydropower Plant. The restored network was subsequently operated with the 135 MW CIIDG coal-fired power plant, energy storage and loads. During restoration, the system remained stable through five transformer energization events, including a transformer rated at up to 100 MVA.
The project also maintained stability while synchronizing different power sources with a phase-angle difference of up to 15 degrees. It operated independently for 3.5 hours, demonstrating its ability to support the local network when separated from the main grid.
Testing included three transitions between grid-connected and islanded operation. Sungrow said voltage deviation remained below 2%, while transient frequency fluctuation remained within 0.15 Hz during grid separation.
The project faced strict testing protocols, complex power-system scenarios, a compressed construction schedule and rainy-season conditions with ambient temperatures reaching 40°C. Sungrow said its team completed hot commissioning and three rounds of performance tests within 20 days. The company also provided services covering storage and monitoring system design, EPC-related support, equipment design, commissioning and O&M.