In the rapidly evolving energy landscape, the integration of renewable energy sources like wind and solar power into the grid is accelerating. However, this surge in capacity brings new challenges, particularly low-frequency oscillations that can destabilize the power system. A groundbreaking study led by Shixian Sheng from the School of Electrical Engineering at Southwest Jiaotong University in Chengdu, China, addresses this issue head-on, offering a novel solution that could reshape how we manage renewable energy integration.
The research, published in ‘Zhongguo dianli’ (China Electric Power), focuses on the cooperative control of virtual synchronous wind farms and photovoltaic (PV) power stations. The study delves into the principles of virtual synchronous generator (VSG) control and additional damping control for doubly-fed induction generators (DFIG), which are crucial for enhancing system damping and mitigating low-frequency oscillations.
Sheng and his team designed additional damping controllers that respond to changes in active power at the grid-connection point of DFIG. These controllers are integrated into the active power control loop of the VSG wind farm and the controller of PV power stations. The innovative aspect of their approach lies in the cooperative control strategies, which adapt based on the operating areas of DFIG. When DFIG is in the constant speed zone, the pitch control’s slow response and limited effectiveness in suppressing oscillations are compensated by the PV power station, which outputs additional power to stabilize the system.
“The key innovation here is the dynamic adjustment of control strategies based on the operating conditions of DFIG,” Sheng explains. “By leveraging the strengths of both wind and solar power, we can create a more resilient and stable power system.”
This research has significant commercial implications for the energy sector. As renewable energy sources become more prevalent, the ability to manage low-frequency oscillations will be crucial for maintaining grid stability. The cooperative control method proposed by Sheng and his team offers a practical solution that can be implemented in real-world scenarios, enhancing the reliability and efficiency of power systems.
The study’s findings were verified through a simulation system that included both wind farms and PV power stations. Prony analysis and time-domain simulations confirmed the effectiveness and correctness of the cooperative control method, paving the way for future developments in the field.
As the energy sector continues to evolve, research like Sheng’s will be instrumental in shaping the future of renewable energy integration. By addressing the challenges posed by low-frequency oscillations, this study opens new avenues for innovation and improvement in power system management. The cooperative control method not only enhances grid stability but also underscores the importance of integrating diverse renewable energy sources for a more sustainable and resilient energy future.
