Main Developers: Tang Guangfu, Xin Bao’an, He Zhiyuan, Ma Weimin, Tian Jie, Zhang Jin, Xie Qingfeng, Guo Xianshan, Wang Shanshan, Zhong Zhiyi, Zha Kunpeng, Li Tan, Wang Haijiao, Qi Lei, Hu Jinsong

Participating Organizations:State Grid Corporation of ChinaState Grid Economic and Technological Research Institute Co., Ltd.China Electric Power Research Institute Co., Ltd.NR Electric Co., Ltd.China Electric Power Research Institute (EPRI) Power Engineering Co., Ltd.Xi’an Electric Co., Ltd.North China Electric Power UniversityNorth China Power Grid Co., Ltd.State Grid Jiangsu Electric Power Co., Ltd.Central Southern China Electric Power Design Institute Co., Ltd., China Power Engineering Consulting Group

Driven by the low-carbon energy transition and large-scale development of new energy, the power system is in urgent need of transformation. VSC-HVDC grid formation represents a new-generation power transmission technology following AC transmission and conventional HVDC transmission, featuring a fundamental shift in control modes from uncontrolled and semi-controlled to fully controlled operation. As a core enabler for building a new-type power system and a strategically critical technology to boost new energy development and safeguard national energy security, VSC-HVDC grid formation faces formidable challenges including theoretical innovation, system construction, operational control and equipment integration. The technology is extremely sophisticated, with no mature references available domestically or internationally. Supported by programs such as the National Key R&D Program of China, the project team spent 20 years accomplishing original innovation from scratch. The major scientific and technological innovations are summarized as follows:

First, a fundamental theoretical system for VSC-HVDC grid formation has been established.Breakthroughs have been achieved in systematic mathematical characterization, multi-modal energy conversion analysis, transient and steady-state behavior analysis, revealing multi-level internal mechanisms of multi-converter DC grid interconnection and the coupling between AC and DC power networks.

Second, methodologies for constructing VSC-HVDC grid formation systems have been proposed.A series of flexible grid connection topologies for multi-scenario and multi-converter applications have been created. A system parameter design method under severe conflicts between transient impacts and safety boundaries is put forward, resolving structural difficulties arising from inherent characteristic differences between multiple converters and AC systems, and providing standardized structural paradigms for VSC-HVDC grid formation.

Third, operational control technologies for VSC-HVDC grid formation are conquered.A hierarchical station-grid control method for multi-agent VSC-HVDC grids is proposed. Breakthroughs are realized in multi-converter coordination, wide-area power mutual support, and high-resilience stability support, addressing worldwide challenges including insufficient grid stability and cascading fault propagation.

Fourth, equipment integration technologies for VSC-HVDC grid formation are achieved.A series of equipment including ±800 kV ultra-high voltage hybrid cascaded converter valves, controllable self-recovering energy dissipation devices and large-capacity converter transformers are developed, with core parameters ranking among international leading levels. A comprehensive engineering technical system for VSC-HVDC grid formation is established for the first time.

The project outcomes provide core technical support for developing the new-type power system, facilitating the pivotal upgrade of power grids from "rigid" to "flexible", and driving domestic high-end power equipment and complete technologies to enter the global market. Six domestic VSC-HVDC projects have been put into operation, namely Nanhui, Zhoushan, Xiamen, Yu-E, Zhangbei and Baihetan–Jiangsu. Four major overseas projects are under construction in Germany, Saudi Arabia and other countries, alongside five overseas technical consulting services delivered for Germany, the United Kingdom and the Netherlands. Forming a standardized implementation system, the achievements offer mature, replicable and promotable Chinese solutions for global energy transition.