Introduction  Due to the dense load, complex grid structure, and close electrical connections in the Guangdong power grid area, there are three major problems for a long time: the risk of large-scale power outages, the interaction between AC and DC, and the excessive short-circuit current, making it difficult to meet the needs of future power load development and flexible system regulation.

  Method  To address the above issues, a high-performance VSC-HVDC (Voltage Source Converter-based High Voltage Direct Current) back-to-back project was constructed in the core area of Guangdong Power Grid, and a new generation of high-performance VSC-HVDC back-to-back technology was studied and adopted. The VSC-HVDC interconnection control of complex power grids, the development of highly reliable and high-performance converter valves, and the design of green and efficient converter stations were deeply studied. The upgrade of VSC-HVDC back-to-back technology was achieved.

  Result  The project successfully achieved automatic control of asynchronous power flow, significantly reducing the link delay of the control and protection system, developed high-performance and highly reliable VSC-HVDC converter valves, and optimized the design in terms of noise reduction, loss reduction, water conservation, and other aspects of the converter station. A comprehensive perception system for the converter station was built, achieving intelligent operation and maintenance. At present, the project is running well.

  Conclusion  The VSC-HVDC back-to-back project of Guangdong Power Grid has solved the three major stability problems faced by the multi DC feeder receiving end grid for a long time and enhanced the long-term safe and reliable power supply capacity of the Guangdong-Hong Kong-Macao Greater Bay Area.