#China #Renewable Energy #Sungrow #Qinghai #Wideband Oscillation

Sungrow Leads in Renewable Energy Stability with Innovative Oscillation Techniques

Sungrow, a leading provider of photovoltaic (PV) inverters and energy storage systems, has achieved a remarkable milestone in renewable energy through its recent field test conducted at a 500 MW solar-plus-storage plant located in Qinghai, China. The company successfully reproduced and suppressed wideband oscillation, a significant technical accomplishment that addresses one of the critical challenges facing increasing renewable energy penetration worldwide.

Understanding the Challenge of Wideband Oscillation

As more renewable energy sources are integrated into the power grid, the issue of wideband oscillation has surfaced as a formidable obstacle. Such oscillations can lead to severe consequences, including the disruption of grid stability and the disconnection of renewable plants. Historical data reveals alarming incidents: for instance, in 2014, the BorWin1 offshore HVDC project in Germany experienced damaging oscillations, leading to a six-month shutdown and significant losses. Similarly, the Hornsea offshore wind farm in the UK witnessed widespread disconnection due to subsynchronous oscillations, affecting millions of users.

Despite the clear dangers associated with oscillations, replicating these phenomena in real-world environments for research purposes has been extremely challenging. Until now, many studies on oscillation suppression have remained largely theoretical or conducted via simulations, lacking systematic validation in actual power plants.

Sungrow's Groundbreaking Approach

To tackle this issue, Sungrow, alongside industry partners, conducted a highly specialized field test at the Qinghai plant, employing their advanced PV inverters throughout the facility. This test aimed to create controlled weak-grid conditions to investigate the factors contributing to oscillation phenomena.

Controlled Reproduction of Oscillation

The test identified three primary factors influencing oscillation behaviors: power output, system short-circuit ratio (SCR), and control parameters. By manipulating these variables, Sungrow engineers successfully reproduced localized system oscillations, a feat not previously accomplished in an operational plant environment.

Rapid Suppression Mechanisms

The field test also evaluated the oscillation suppression capabilities of Sungrow's inverters under varying grid conditions. Utilizing the company's proprietary grid-strength adaptation technology, the inverters were able to assess grid strength within just 40 milliseconds. By dynamically adjusting control strategies, they effectively stabilized voltage and frequency fluctuations. Notably, this field test validated the effectiveness of Sungrow's grid-forming control strategy. This strategy supports stable operations over a wide range of SCR values (from 1 to 40) and mitigates the risk of transient overvoltages, ensuring the reliability of grid connections.

Implications for the Future of Renewable Energy

Successfully demonstrating the controlled reproduction and suppression of wideband oscillation marks a watershed moment in renewable energy engineering. This advancement is expected not only to bolster the stability of renewable energy plants in weak grid environments but also significantly reduce the incidence of disconnections triggered by oscillation events. Moreover, it unlocks the potential for higher power export capacity for plants connected to unstable grids, decreasing generation losses.

Pan Nian'an, Chief Engineer and Chief Expert for Utility PV BU at Sungrow, emphasized the importance of these advancements, stating, "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." He further noted that Sungrow will persist in its commitment to research and development in grid technologies, with particular emphasis on innovative measures like wideband oscillation suppression, grid-forming control, and multi-energy coordination.

As the quest for stable and efficient renewable energy continues, Sungrow's achievements pave the way for future innovations that support a more resilient energy grid and facilitate the transition toward sustainable power systems worldwide.