Main Participants: ZHAO Yongfei, LIU Xiaobo, HAN Changlin, BAI Jianfei, LU Xiaofang, PENG Demin, ZHANG Weijun, ZHANG Xi, BAN Xindong, LI Chenglong, GONG Chuanli, DENG Xiaogang, WEN Zhengguo, ZHANG Xu, YANG Chunxia, YANG Quanfu, CHEN Kangbei, WANG Peng, AN Qi, ZHAO Ziqing

The National Energy Administration (NEA) of China issued the Mid to Long-term Development Plan for Pumped-Storage Hydroelectricity (2021-2035) that aims to accelerate the development of pumped storage projects in China, in an effort to adapt to the demands from new-type power systems and a larger and higher adoption of new energy sources. It also intends to help the country achieve its goals of carbon peaking and carbon neutrality.

Advanced automatic control technologies play an important part in ensuring safe and reliable operation of pumped-storage power stations. Automatic control systems for pumped-storage power stations, featuring multiple operating modes, complex process control and numerous monitoring and control points, are vital for power systems.

Born out of over a decade of research innovation, the team developed indigenous automatic control technologies for large pumped-storage units that make adequate alternatives to foreign technology solutions. The research hence contribute to a higher level of automation and safe operation and management of large pumped-storage units in China.

·   Having designed an operating condition conversion process and a safe and reliable control process for pumped-storage units according to their conversion requirements;

·   Having developed technologies for simulation and test platform for pumped-storage units in different operating modes; conducted simulation tests with a dynamic combined input of both virtual and real data to substitute on-site tests with actual machines, hence improving project efficiency;

·   Having developed a short-time-window, multi-machine and multi-mode booting-up technology, which enables automatic planning of the number of pumps to start, as well as nodes, static frequency converter (SFC) matching, and the optimal conversion between operating modes such as stationary (S), pumping condenser (PC) and pumping (P);

·   Having conducted systematic research on real-time diagnosis technologies for unit control processes which enable real-time monitoring of process execution, faults diagnosis and identification of fault steps, to shorten the time for fault identification and enable intelligent diagnosis of faults in unit processes.

·   Having established a credible judgment model for the operating modes of main and auxiliary equipment in large pumped-storage units, and based on the model developed a safe and reliable control process to ensure that main and auxiliary equipment at a power station can be monitored, viewed, controlled and adjusted;

·   Having proposed for the first time a systematic safety control strategy for pumped-storage units featuring high capacity, high water head, high rotate speed and multi-SFC booting-up, which improves equipment operation reliability and safety;

·   Having developed a short-time-window, multi-machine and multi-SFC pump booting-up technology with automatic pumping control and joint pumping control (PJC); enabling  rapid regulation of pumped-storage power stations, with up to three units turned on pumping mode within 15 minutes;

·   Having developed a simulation test platform for the control process of large pumped-storage units and conducted full-mode, full-condition and full-output tests, shortening the time for commissioning on the first unit with water from the conventional 80-100 days to about 30 days;

·   Having developed a real-time diagnosis technology for the control process of pumped-storage units, enabling real-time monitoring of process execution, precise diagnosis of unit process with seconds, and improved operation stability.

The achievements have been applied to China’s pumped storage power stations including the Qingyuan Station, the Changlongshan Station, the Yangjiang Station and the Taishan Station, and are being applied to the renovation of the monitoring system at the Huizhou Pumped-storage Power Station.

With richer experiences in the homemade automatic control systems installed and operated in China’s pumped storage power projects, benefits can be expected for the further development of automatic control technologies and more competitive homemade solutions.

Fig.1 Multi-units, multi-mode booting-up technology

Fig.2 Real-time diagnosis of the control process of pumped-storage units

Fig.3 The computer monitoring system of the Qingyuan Pumped Storage Power Station

Fig.4 CGTN’s coverage of the computer monitoring system of the Yangjiang Pumped Storage Power Station