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2023

Jinfeng Technology's low-frequency fan renovation project is delivered through grid connection! Serve the world's first flexible low-frequency transmission demonstration project!

Recently, the customized unit renovation project in Dachen Island, Taizhou, Zhejiang was successfully connected to the grid and delivered. This project provides the world's first flexible low-frequency transmission demonstration project, the Taizhou 35 kV flexible low-frequency transmission project, with the world's first low-frequency wind turbine as the power output. It successfully explores the integrated key technologies and wind power equipment on the power side for offshore flexible low-frequency transmission, and has milestone significance for the large-scale development of COSCO offshore wind power resources in the future.

The Zhejiang Taizhou Flexible Low Frequency Transmission Demonstration Project (hereinafter referred to as "Taizhou Flexible Low Frequency Transmission Project") is led by State Grid Zhejiang Electric Power Co., Ltd. (hereinafter referred to as "State Grid Zhejiang Electric Power"), aiming to use flexible low frequency transmission technology to transmit offshore wind power from Dachen Island in Taizhou to the onshore power grid, achieving efficient utilization of surplus offshore wind power resources.

As the operator of Dachen Island Wind Farm, Zhejiang Xingxing Wind Power Co., Ltd. (hereinafter referred to as "Xingxing Wind Power") actively responds to the demand of the power grid and collaborates with Goldwind Technology to complete the customized unit renovation project, helping to build a land island wind power interconnection system and achieve optimal allocation of offshore wind power resources.

Low frequency output and typhoon prevention design, highly customized

The Dachen Island project involves the renovation of three wind turbines, with two low-frequency units connected to the grid on June 3rd and 12th, and one power frequency unit connected to the grid on June 30th. According to the person in charge of the wind farm, compared to unmodified units with similar wind resource conditions, the power generation of the units after the technical renovation has significantly improved, successfully achieving the expected technical renovation goals.

The Dachen Island project has become a highly technically challenging and innovative customized project due to its involvement in low-frequency unit renovation and island typhoon conditions.

Low frequency wind turbines are a complete set of technical equipment specifically developed for flexible low-frequency transmission technology. They are a new form of wind turbine power supply that can directly output 20Hz low-frequency AC power through a full power converter, meeting the power side requirements of flexible low-frequency transmission technology. In low-frequency scenarios, the grid friendly control effects of fault traversal, reactive power/voltage control, power quality, and harmonic suppression on the grid side of wind turbines have all changed, and the testing indicators and methods are different from those of power frequency wind turbines.

After systematic technological development iteration and modeling and simulation verification, Goldwind Technology has achieved significant breakthroughs in areas such as low-frequency converters and control, low-frequency grid connection technology, low-frequency overall system control and protection strategy, low-frequency modeling and simulation technology, low-frequency testing technology, power intake design technology, and sea suitability design technology. It has successfully explored the integrated key technical equipment and implementation path on the power side for offshore flexible low-frequency transmission.

Typhoon is a common catastrophic weather along the coasts of East and South China in China. The Dachen Island technical renovation project must apply typhoon prevention design strategies to ensure the safe operation of the units. In terms of typhoon area adaptability strategy, the technical renovation unit has adopted a "multiple protection system", including the passive safety performance and active safety strategy of the unit under typhoon conditions, which comprehensively enhances the typhoon area adaptability of the unit.

Overcoming numerous challenges and delivering and putting into production on schedule

PPT | State Grid Intelligent Research Institute Zhao Guoliang: Flexible Low Frequency AC Transmission Technology and Applications for Offshore Wind Power

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