On August 7, the 500kV grid connection system of the Zhaoqing Langjiang Pumped Storage Power Station, the first variable-speed pumped storage project in the Guangdong-Hong Kong-Macao Greater Bay Area and operated by CSG Energy Storage Company, successfully completed its energization test. This milestone marks the station's official entry into the critical stage of grid-connection commissioning, laying a solid foundation for the subsequent specialized commissioning of China's first large domestically manufactured variable-speed pumped storage unit and the full-scale commercial operation of the plant. It represents a landmark breakthrough in the project's construction progress.
This energization test adopted the reverse power transmission mode, whereby power was fed back from the grid to the station, aiming to verify the operational reliability of the equipment in the 500kV grid connection system and the stability of system coordination under full-voltage conditions. As the first large-scale pumped storage power station in China to apply a fully integrated intelligent control and protection system across the entire plant, the Zhaoqing station's energization test not only comprehensively validated the integrity and correctness of high-speed communication and sharing of real-time control and protection information for equipment within the energization scope, but also achieved transparent operation of key equipment and control circuits, as well as low-code visual intelligent fault diagnosis. This provides vivid practical experience for the construction of digitalized and intelligent pumped storage power stations and holds significant demonstrative value for promoting the digital and intelligent transformation of China's energy sector and supporting the development of a new-type power system.
The equipment energized in this test primarily included the switchyard GIS, the 500kV No. 1 high-voltage cable, the No. 1 main transformer, and its full set of auxiliary equipment on both the high- and low-voltage sides. Simultaneously, multiple systems—including protection, measurement, monitoring, and automation—operated in coordinated synchronization, comprehensively verifying the compatibility and safety of the entire electrical system. During the test, three full-voltage impulse energization tests were conducted on the 500kV switchyard, the underground GIS equipment, and the No. 1 high-voltage cable, while five full-voltage impulse energization tests were performed on the No. 1 main transformer. All high-voltage equipment successfully withstood the full-voltage impulse tests, with excellent performance indicators. The corresponding communication, protection, measurement, monitoring, and control equipment demonstrated intact and correct data transmission, parameter acquisition, phase sequence, polarity, surveillance, and control functions, marking the successful initial energization of the 500kV system.
The Zhaoqing Langjiang Pumped Storage Power Station is a key project under China's national medium- and long-term pumped storage development plan and the first variable-speed pumped storage demonstration station in the Guangdong-Hong Kong-Macao Greater Bay Area. The station's 500kV single-circuit transmission line connects to the Yucheng Substation, enabling grid-connected power transmission via the Xuyu-Jia line, making it a critical backbone project for peak shaving and energy storage in the Guangdong power grid. With a total installed capacity of 1,200MW, the station innovatively features three fixed-speed units with a unit capacity of 300MW each and one domestically developed, independently researched variable-speed reversible unit with a unit capacity of 300MW, with a designed annual power generation of 1.35 billion kWh. Compared with conventional pumped storage units, the variable-speed unit offers more flexible power regulation and faster grid response, enabling precise adaptation to the frequency and voltage regulation requirements of a new-type power system. The successful energization of the 500kV system provides complete electrical operating conditions for the subsequent specialized commissioning, performance verification, and functional optimization of the variable-speed unit, effectively ensuring that the core technological advantages of this distinctive unit are fully realized.
To successfully accomplish this critical milestone of 500kV system energization, during the preparatory phase, the CSG Energy Storage Construction Management Company took the lead in coordinating with the CSG Energy Storage Operation Company, the CSG Energy Storage Maintenance and Testing Company, as well as supervision, design, construction, and equipment manufacturing entities. Drawing on the standardized documentation of CSG Energy Storage Company, namely the "Standardized Documentation for Commissioning and Trial Operation of Pumped Storage Units of CSG Energy Storage Company," and fully leveraging the professional strengths of its specialized subsidiaries, the team systematically organized and executed the task list for grid connection system energization on schedule. A total of 12 documents were compiled, including the "Trial Operation Plan for the 500kV Xuyu-Jia Line and the 500kV Zhaoqing Pumped Storage Power Plant," the acceptance checklist for startup test items, and startup equipment operation tickets, with regular pre-startup acceptance meetings convened. Additionally, targeted training sessions were conducted on the principles and operation of equipment including the 500kV GIS, main transformer cooling systems, 10kV diesel generators, protection systems, online monitoring systems, and control systems, comprehensively enhancing the operational skills of maintenance personnel and laying a solid foundation for the subsequent operation and maintenance of energized equipment.