With a round of sunrise rising above the horizon, the street lights on the streets of Lahore, the capital of Punjab Province in eastern Pakistan, slowly went out, as if the city had pressed the start button to start a new day of busyness. In the southern suburb of this millennium old city, in the Lahore converter station of the Motyari Lahore (Mera) DC transmission project, the Pakistani shift leader Zuber Tufel is preparing for the morning routine inspection. Tufeiler is a native of Lahore and joined the project after graduating from Lahore University of Engineering and Technology. "At that time, there was no High-voltage direct current project in Pakistan, and I knew nothing about this technology. I was assigned an experienced Chinese engineer on the project, who led me to grow up quickly like a teacher guiding students," Tufel said. Mehra DC transmission project is the first High-voltage direct current project in Pakistan invested, constructed and operated by China National Grid Corporation, and also the first power transmission and transformation project under the China–Pakistan Economic Corridor, an important pilot project for the joint construction of the "the Belt and Road". It was officially put into commercial operation in September 2021. Li Shoujin, the Chinese shift leader of Lahore converter station of Mehra DC transmission project, is the engineer with Tufeller. At this moment, they are wearing work clothes printed with the flags of China and Pakistan, wearing yellow safety helmets, and carrying out operation and maintenance work together. There are many Chinese equipment on the project, "Li Shoujin told reporters, pointing to a large equipment with the" China Western Power "logo." This converter transformer responsible for energy transmission is one of the core equipment. "The converter transformer is one of the most important equipment at the station, and its research and development production location is another millennium old city - Xi'an, China. In 1992, Xi'an and Lahore became Sister city. Since then, the relationship between these two "sisters cities" has continued. In Xi'an, Zhao Qi, the general manager of China Xidian Electric Co., Ltd. (China Xidian), told reporters that as early as December 2014, China Xidian had provided technical solutions for the Mura DC transmission project. Relying on the industry-leading brand strength, world-class DC transmission manufacturing technology and market performance, China XD successfully obtained the letter of acceptance for the converter transformers of the Mertiari and Lahore stations of the project. The eastern part of Pakistan is constantly experiencing high temperatures, and the environmental conditions at the transmission and reception end of the project's converter station are very harsh. Not only does the highest environmental temperature exceed 50 degrees Celsius, but it is also dry and rainy all year round, with frequent sandstorms and high UV intensity. Therefore, based on the application of mature converter transformer design solutions, the design team of Xidian Xibian consists of technical experts and core design personnel to form a special research group, optimize and improve the main component structure, sleeve installation method, etc., improve the product design scheme, enhance product technical performance, and ensure the reliability of product operation. The product of this project is crucial and the engineering is significant, so there should be no carelessness, "said Zeng Guorong, deputy director of the coil workshop at Xidian West Transformer Co., Ltd. Xi'an, China, and Lahore, Pakistan, two ancient cities, have become close to each other because of the "electricity". From design and production to installation and application, converter transformer equipment from China has played a significant role in Pakistan's power grid. "Our project has greatly reduced the loss of north-south power transmission in Pakistan, and reduced the power failure caused by transmission loss