Sungrow Stabilizes 500 MW Plant with New Oscillation Tech

Sungrow has demonstrated the first controlled reproduction and suppression of wideband oscillation at a live 500 MW solar-plus-storage plant in Qinghai, China. The engineering test addresses a critical stability issue that has historically forced renewable assets to disconnect from the grid during high-penetration periods. By validating these controls in a real-world environment, the company moves beyond theoretical simulations to practical engineering solutions for weak grid conditions.

The initiative aims to prevent the economic losses associated with oscillation events, such as the six-month shutdown of Germany’s BorWin1 offshore project or the widespread disconnection at the UK’s Hornsea wind farm. These past incidents highlighted how severe instability can damage hardware and disrupt service for millions of users. Sungrow’s field test seeks to eliminate such risks by enabling inverters to self-stabilize during transient disturbances.

Field Validation of Stability Controls

Working with industry partners, Sungrow deployed its PV inverters across the Qinghai site to establish weak-grid conditions. The team identified three primary drivers of instability: power output levels, the system short-circuit ratio, and specific control parameters. By isolating these variables, the engineers successfully reproduced a localized system oscillation in a controlled manner, bridging the gap between laboratory research and on-site operational reality.

The core objective was to verify that suppression methods could be executed safely in a live power plant. Previous research remained largely confined to simulations because the phenomenon is complex and unpredictable. This field test provides systematic validation that effective suppression strategies can be implemented without risking uncontrolled grid failures or equipment damage.

Inverter Response and Grid Adaptation

During the suppression phase, Sungrow’s inverters utilized patented grid-strength adaptation technology to respond to the oscillation. The system identified the grid’s strength within 40 milliseconds, a rapid response time that allowed for immediate adjustment of control strategies. This quick reaction enabled the inverters to stabilize both voltage and frequency, effectively damping the oscillation before it could spread or cause disconnection.

The test also confirmed the efficacy of grid-forming control strategies in maintaining stability across a broad range of grid conditions. The inverters operated stably with a short-circuit ratio ranging from 1 to 40, demonstrating robustness in extremely weak grid environments. Additionally, the system mitigated transient overvoltage, a common issue that can stress power electronics and reduce the lifespan of plant equipment.

Operational Impact and Future Deployment

This achievement allows renewable plants to maintain stable operation under conditions that previously risked forced shutdowns. By preventing oscillation-induced disconnections, the technology unlocks greater power export capacity for facilities connected to weak grids. This directly translates to reduced generation losses and improved revenue reliability for plant operators who depend on continuous grid integration.

Pan Nian’an, Chief Engineer for Utility PV at Sungrow, stated that autonomous fault self-healing is essential for renewable energy to become a reliable power source. The company plans to continue advancing grid technologies, focusing on wideband oscillation suppression, grid-forming control, and multi-energy coordination. These innovations aim to strengthen the technical foundation for stable grid integration and efficient utilization of solar and storage assets.