5月16日，由中国能建广东火电承建的世界首个城市中心全户内紧凑化柔性直流换流站——广州220千伏天河棠下柔直背靠背工程顺利封顶。该工程高达49米，是目前国内陆上建筑高度最高的柔性直流换流站。

On May 16th, the world's first fully indoor, compact and flexible DC converter station in a city center - the Guangzhou 220-kilovolt Tianhe Tangxia Flexible DC Tieback Project, which was constructed by China Energy Engineering Group Guangdong Hydropower, was successfully topped out. The project is 49 meters high and is currently the tallest flexible DC converter station on land in China.

工程选址位于广州市中心城区，场地极度狭小，且紧邻正在运行的220kV棠下变电站，施工场地极度受限。同时，完成深基坑、超高钢结构吊装和高空作业，建设难度呈几何级上升。

The project site is located in the central urban area of Guangzhou. The site is extremely small and is adjacent to the operating 220kV Tangxia Substation. The construction site is severely restricted. At the same time, completing deep foundation pits, hoisting of ultra-high steel structures and high-altitude operations have led to an exponential increase in construction difficulty.

第一关：深基坑“贴身”作业。基坑面积达6500平方米，开挖深度超过10米，与运行中的220kV棠下变电站最近距离仅8米。稍有不慎，就可能影响变电站安全运行，风险等级极高。

First challenge: "Close-up" operation in a deep foundation pit. The area of the foundation pit is 6,500 square meters, and the excavation depth exceeds 10 meters. The closest distance to the operating 220kV Tangxia Substation is only 8 meters. Even a slight mistake could potentially affect the safe operation of the substation, and the risk level is extremely high.

第二关：巨型钢结构“高空穿针”。整个工程用钢量约14000吨，最大单件构件重达20吨，最高起吊高度接近47米（相当于16层楼高）。在城市中心狭窄场地上进行超高层、大吨位钢构吊装，对精度和稳定性提出了严苛要求。

Second stage: "High-altitude Needle Insertion" with massive steel structure. The entire project utilized approximately 14,000 tons of steel, with the heaviest single component weighing up to 20 tons, and the maximum lifting height reaching nearly 47 meters (equivalent to 16 floors). The super high-rise and large-tonnage steel structure hoisting operation in the narrow urban area presented extremely strict requirements for precision and stability.

第三关：工期紧、交叉作业多。场地有限，塔吊、汽车吊等大型设备难以铺开，同时需保证周边交通与电网安全。

The third challenge: The construction schedule is tight and there are numerous concurrent operations. The site is limited, making it difficult to deploy large equipment such as tower cranes and truck cranes. At the same time, it is necessary to ensure the safety of surrounding traffic and the power grid.

第一招：贴身守护，化解深基坑风险。针对距运行中220kV棠下变电站仅8米的超深基坑（6500平方米、开挖超10米），项目团队采用自动化监测系统，实时掌控基坑与变电站的位移、沉降数据，配合分层开挖、加强支护等措施，确保“零影响、零事故”。

Method 1: Close monitoring to mitigate risks of deep foundation pits. For the extremely deep foundation pit (6,500 square meters, with a depth of over 10 meters) located only 8 meters away from the operating 220kV Tangxia Substation, the project team employed an automated monitoring system to continuously track the displacement and settlement data of the foundation pit and the substation. They also implemented measures such as layered excavation and strengthened support to ensure "zero impact and zero accidents".

第二招：精准吊装，攻克超高钢结构。面对14000吨用钢量、最大构件20吨、起吊近47米（约普通居民楼16层高度）的挑战，团队利用BIM模拟吊装路径，科学调度10余台塔吊与汽车吊，优化构件进场及吊装顺序，最大限度减少设备干涉和等待时间，实现高空“穿针引线”般的精准就位。

Method 2: Precise lifting, overcoming the challenge of ultra-high steel structures. Facing the challenge of 14,000 tons of steel usage, the largest component weighing 20 tons, and a lifting height of nearly 47 meters (approximately the height of a 16-story ordinary residential building), the team used BIM to simulate the lifting path, scientifically scheduled more than 10 tower cranes and truck cranes, optimized the entry and lifting sequence of the components, and minimized equipment interference and waiting time, achieving precise positioning like threading a needle from a high altitude.

第三招：高效协同，突破工期与场地瓶颈。在狭小场地内实行两班轮作制，人停机不停，合理划分作业区、错峰交叉作业。仅用7个月完成主体钢结构安装，刷新同类工程建设速度纪录，为城市中心复杂环境下的高难度输变电工程树立了新标杆。

Method 3: Efficient collaboration to break through the constraints of construction schedule and site. In a limited space, a two-shift rotation system was implemented, with workers stopping but machines remaining operational. The work areas were reasonably divided and overlapping operations were carried out at different times. The main steel structure installation was completed in just 7 months, setting a new record for the construction speed of similar projects and establishing a new benchmark for high-difficulty power transmission and transformation projects in complex urban environments.

从“贴身守护”到“精准吊装”再到“高效协同”，广东火电项目团队在方寸之间施展硬功夫，在极限中创纪录。随着该工程顺利封顶，世界首个城市中心全户内紧凑化柔性直流换流站雏形已现，为后续设备安装及按期投运奠定了坚实基础。

From "close protection" to "precise hoisting" and then to "efficient collaboration", the Guangdong Thermal Power Project team demonstrated their expertise within a confined space and achieved records in extreme conditions. With the successful topping-out of the project, the prototype of the world's first fully indoor, compact and flexible DC converter station in the city center has taken shape, laying a solid foundation for subsequent equipment installation and on-time commissioning.

项目位于广东省广州市天河区天河智谷广棠片区，是世界首个城市中心全户内紧凑化柔性直流换流站，也是国内首个超大城市电网嵌入式多端柔直项目。本期新建1组700MW直流线路和3组450MW直流线路，新建电缆长0.18千米，本期出线220kV共4回。

The project is located in the Guangtang area of Tianhe District, Guangzhou City, Guangdong Province. It is the world's first fully indoor compact flexible DC converter station in the city center, and also the first multi-terminal flexible DC project embedded in the power grid of a megacity in China. This phase will build 1 group of 700MW DC lines and 3 groups of 450MW DC lines. The newly constructed cables will be 0.18 kilometers long. In this phase, there will be a total of 4 220kV outgoing lines.

建成后可提升广州市核心区域供电能力70万千瓦，有效发挥柔性直流技术快速调节、黑启动、联网孤岛转换等优势，提升区域电网抵御严重自然灾害的能力，提高区域供电可靠性，满足广州珠江南北电网互济需求。

After completion, it will increase the power supply capacity of the core area of Guangzhou by 700,000 kilowatts. It will effectively leverage the advantages of flexible DC technology such as rapid regulation, black start, and interconnection island conversion, enhancing the region's ability to withstand severe natural disasters, improving regional power supply reliability, and meeting the mutual assistance needs of the north and south power grids in the Pearl River Delta region.