Sungrow has achieved what it describes as a world first by controllably reproducing and successfully suppressing wideband oscillation at an operational 500 MW solar-plus-storage plant in Qinghai, China, marking a significant shift in efforts to move this area of grid stability research from theoretical modeling into real-world engineering practice.

A Longstanding Challenge for Renewable Integration

As renewable energy penetration rises across global power systems, wideband oscillation has emerged as one of the most difficult stability problems facing grid operators and plant developers.

The phenomenon, which spans a broad range of frequencies, can in severe cases cause renewable plants to disconnect from the grid entirely or shut down, with substantial consequences for power supply reliability and project economics.

The scale of past incidents illustrates the severity of the problem. In 2014, the BorWin1 offshore high-voltage direct current project in Germany experienced oscillations in the 250 to 350 Hz range.

The event damaged filter capacitors on the offshore converter platform and triggered a shutdown lasting approximately six months, resulting in significant economic losses to the local utility.

Five years later, in 2019, the Hornsea offshore wind farm in the United Kingdom experienced widespread disconnection caused by subsynchronous oscillation, resulting in a loss of approximately 3.2 percent of system load and disrupting power supply to around one million users.

Despite the severity of such incidents, the complex and unpredictable nature of wideband oscillation has made it extremely difficult to safely and controllably reproduce the phenomenon at real-world plants, let alone validate suppression methods in the field.

Research has therefore remained largely confined to theoretical analysis and simulation environments, with limited systematic testing conducted in actual operating power plant conditions.

The Field Test: Conditions and Methodology

To bridge the gap between laboratory simulation and operational reality, Sungrow and its industry partners conducted the field test at the 500 MW site using Sungrow PV inverters deployed across the plant. The test was carried out in Qinghai, a province in northwestern China that has become a significant hub for large-scale renewable energy development.

The first phase of the test focused on controllably reproducing a localized system oscillation. Engineers established weak-grid conditions at the site and identified three key contributing factors: power output levels, the system short-circuit ratio, and control parameters.

Using these variables, the team was able to trigger oscillation in a controlled manner, a step that had not previously been demonstrated at this scale in a real-world plant environment.

Suppression Technology and Performance Results

With oscillation successfully reproduced, the test then evaluated the suppression performance of Sungrow's PV inverters under different grid conditions. Central to the suppression capability is what Sungrow describes as its patented grid-strength adaptation technology.

Under the test conditions, the inverters were able to identify grid strength within 40 milliseconds, adjust their control strategies accordingly, and rapidly stabilize both voltage and frequency.

The test also validated the effectiveness of grid-forming control as a suppression mechanism for wideband oscillation. Sungrow's grid-forming control strategy demonstrated stable operation across a short-circuit ratio range of 1 to 40, a broad operational envelope that covers conditions from extremely weak to strong grid connections.

The technology also demonstrated effectiveness in mitigating transient overvoltage, another risk associated with oscillation events in renewable power systems.

Implications for Grid Stability and Plant Operations

Sungrow stated that successfully reproducing and suppressing wideband oscillation at a real-world 500 MW plant represents a critical step in moving suppression techniques from the laboratory into engineering practice. The company identified several potential practical benefits stemming from this capability.

Plants connected to weak grids could see improved stability and a reduced risk of the grid disconnections that have historically caused prolonged outages and revenue losses.

The advance could also unlock greater power export capacity at sites where weak grid conditions have previously constrained how much energy a plant can deliver to the network.

Additionally, the ability to validate suppression methods in the field rather than through simulation alone could help reduce generation losses associated with oscillation-related curtailment or shutdowns.

Sungrow's Broader Technology Roadmap

Pan Nian'an, Chief Engineer and Chief Expert for the Utility PV business unit at Sungrow, framed the achievement within the company's longer-term vision for renewable energy reliability. Speaking about the results, Pan said that for renewable energy to become a truly stable and reliable source of power, it is essential to develop autonomous fault self-healing and grid-support capabilities.

Pan indicated that Sungrow intends to continue advancing research and development in grid technologies, with a focus on wideband oscillation suppression, grid-forming control, and multi-energy coordination.

The company stated that these efforts are aimed at supporting the stable grid integration and efficient utilization of renewable energy, while strengthening what it described as the technical foundation for a secure and stable energy transition and the development of next-generation power systems.

The announcement was made on September 16, 2026, from Sungrow's headquarters in Hefei, China.

Powering Your Pipeline: Stay Ahead of China's Energy Build-Out

China's power sector is expanding at a pace that leaves little room for missed opportunities; new generation capacity, grid upgrades, and renewable installations are being commissioned across the region faster than ever before. Are you confident your business intelligence is keeping up?

The Global Project Tracking (GPT) platform by Blackridge Research delivers comprehensive, continuously updated intelligence across China's full power project lifecycle, giving developers, contractors, and investors the visibility they need to act with precision and confidence.

From early-stage planning through to project completion, the GPT platform consolidates critical data points into a single, structured environment, eliminating the noise and surfacing the opportunities that matter most to your growth strategy in China energy markets.

• Upcoming Projects

• Tender Notices

• Contract Awards

• Projects Under Construction

• Completed Projects

See the full depth of China's power market intelligence for yourself. Contact the Blackridge Research team today to book a Free Demo of the GPT platform.