China Southern Power Grid: After ten years of hard work, three key technologies of Yangjiang Pumped Storage Power Station have become world-leading

Recently, the China Hydropower Engineering Society held a scientific and technological achievement appraisal meeting in Beijing on "Key Technologies and Applications of 400,000-kW 700-meter Pumped Storage Units". According to the appraisal, the research results of the project have been successfully applied in the Yangjiang Pumped Storage Power Station, which is a supporting project, and have been promoted to Huizhou Zhongdong and other pumped storage power stations, promoting the technological progress of ultra-high head, ultra-large capacity and high stability pumped storage units, with significant economic and social benefits, broad prospects for promotion and application, and reaching the international leading level. This achievement fills the gap in the design and manufacturing of 400,000-kW 700-meter ultra-high head and ultra-large capacity pumped storage units in my country, and promotes the substantial improvement of my country's power generation equipment design and manufacturing capabilities.

In May and June 2023, Yangjiang Pumped Storage Power Station (hereinafter referred to as "Yangxu Power Station") of Southern Power Grid Energy Storage Company has successively passed the international leading appraisal of two key technologies: ultra-high pressure reinforced concrete pressure pipeline construction and unit and system design. The successful completion of this scientific and technological achievement appraisal indicates that the three key technologies of Yangxu Power Station unit development, system design, and waterway construction have reached the international leading level, indicating that my country has achieved a high level of scientific and technological self-reliance in the field of ultra-high head and ultra-large capacity pumped storage projects.

The appraisal committee of the scientific and technological achievements is led by Academicians Zhang Yongchuan and Zhang Zongliang of the Chinese Academy of Engineering, and consists of 13 experts and scholars from Huazhong University of Science and Technology, China Power Construction Group Kunming Survey and Design Institute Co., Ltd., China Hydropower Engineering Society, China Three Gorges Corporation, Xi'an University of Technology, China Hydropower Planning and Design Institute Co., Ltd., China Power Construction Group Beijing Survey and Design Institute Co., Ltd., China Power Construction Group Central South Survey and Design Institute Co., Ltd., China Power Construction Group Chengdu Survey and Design Institute Co., Ltd., China Institute of Water Resources and Hydropower Research, and National Technical Committee for Standardization of Large Generators. The appraisal meeting was chaired by Xi Hao, Executive Vice Secretary-General of China Hydropower Engineering Society. The expert committee listened to the report and reviewed the relevant technical information. After questioning and discussion, it was concluded that the project relied on the independent design and manufacturing of my country's 400,000-kilowatt, 700-meter ultra-high head and ultra-large capacity pumped-storage units. It carried out research and technical breakthroughs to tackle the difficult problems of design and manufacturing of pump-turbines and generator motors, and performance assurance of the transition process of the complex water supply system of "one pipe and three machines". It formed a number of innovative technologies with independent intellectual property rights and developed my country's first set of 400,000-kilowatt 700-meter pump-turbines and generator motors.

It is understood that the process of independence of my country's units has mainly gone through three stages: "bundled bidding, introduction of technology, subcontracting manufacturing", "domestic responsibility, 'when necessary', foreign support", and "independent design and research and development". With the passage of time and the smooth progress of the independence process of 300MW energy-storage units, in 2012, the National Development and Reform Commission, in its reply letter approving the preliminary work of the Yangxu Power Station project, clearly listed the Yangxu Power Station as a supporting project for the independent design and manufacturing of my country's 400,000-kilowatt, 700-meter ultra-high head and ultra-large capacity pumped-storage units, becoming a pioneer demonstrator of my country's 400,000-kilowatt pumped-storage units.

It is reported that the rated capacity of the 700-meter-class 400MW pumped-storage unit of Yangxu Power Station reaches 400MW, the head is 700 meters and the speed is 500 rpm. It is the largest single-unit pumped-storage unit currently put into operation in China. It has very high requirements in hydraulic development and model testing, parameter selection and transition process, electromagnetic design scheme, ventilation and cooling structure, stator and rotor insulation system, thrust bearing structure and unit operation stability. The difficulty of design and manufacturing is among the highest in the world.

China Southern Power Grid Energy Storage Co., Ltd. took the lead, and in conjunction with Harbin Electric Motor Factory, Guangdong Hydropower Research Institute, Tsinghua University and other advantageous resources, through the joint research of "industry, academia, research and application", it took ten years to complete the successful development and demonstration application of the 700-meter-class 400MW pumped storage unit set in Yangjiang, Guangdong. The key indicators of the unit efficiency, oscillation, pressure pulsation, noise and other key indicators measured during operation of the Yangxu unit are better than those of similar units at home and abroad. The results of the "Key Technology and Application of 400,000-kilowatt 700-meter-class Pumped Storage Unit" project have made a successful engineering practice demonstration for the subsequent application of ultra-high head and ultra-large capacity pumped storage units, and provided important support for my country's key technologies of pumped storage units to accelerate the realization of international leadership.

High head and large capacity are the main development direction of pumped storage power stations in the world, which can effectively improve the comprehensive benefits of the project. Yangxu Power Station will be fully operational at the end of May 2022. So far, it has delivered 2.3 billion kWh of clean electricity to the Guangdong-Hong Kong-Macao Greater Bay Area, equivalent to the annual electricity consumption of 600,000 residential users. (Zhou Zan, Zhang Xie)