The security of large power grids is an important part of national security. Over the past 20 years, many countries and regions around the world, including the United States, Canada, Russia, and India, have experienced large-scale blackouts, which have had a significant impact on economic and social development. Since its establishment, State Grid Corporation of China has always focused on tackling key technologies related to power security, achieving a series of original results in areas such as power grid stability theory, simulation analysis, and security defense, making the State Grid the only extra-large power grid in the world that has not experienced a major blackout in the past 20 years.
In terms of system operation, State Grid Corporation of China has developed a large power grid intelligent dispatch control system with completely independent intellectual property rights, carried out research on flexible transmission technology, solved the technical problem of reliable interruption of DC fault current under high voltage and high current operating conditions, and significantly enhanced the ability to manage complex large power grids; vigorously carried out research on source-grid-load-storage friendly interaction technology, built the world's first "large-scale source-grid-load friendly interaction system" in Jiangsu, achieving millisecond-level load control; built the world's largest electricity information collection system covering the most users, with more than 400 million smart meters installed, effectively enhancing the grid's ability to respond to faults and the level of interaction. In terms of fault defense, State Grid Corporation of China has overcome key technologies of the "three lines of defense", built a technical standard system based on the "Guide for Safety and Stability of Power Systems" and an internationally leading large power grid security defense system, achieving precise fault identification, rapid removal, and intelligent handling, effectively preventing large-scale blackouts. In terms of simulation technology, State Grid Corporation of China has broken through major technical problems such as large power grid dispatch operation, wide-area dynamic monitoring, and multi-timescale full-process simulation of AC/DC systems, independently developed and built a new generation simulation system with the strongest simulation capability, the highest computational efficiency, and the most accurate simulation precision, reaching the world's leading level in large power grid safe operation technology.
These achievements have supported the continuous upgrading of China's power grid, providing strong theoretical and technical support for major national projects such as the Three Gorges power transmission system and the UHV AC/DC power grid, ensuring the long-term safe operation of the power grid, and making outstanding contributions to the development of China's power grid into the world's largest extra-large power grid with the highest voltage level, the largest scale, and the longest safe operation record.
III. Strengthening Innovation in New Energy Grid Integration and Operation Technology to Promote China's Clean and Low-Carbon Energy Transition
With the deepening of a new round of energy revolution, new energy is developing rapidly worldwide. Due to the characteristics of randomness, intermittency, and volatility of new energy, its high-proportion integration will change the operating characteristics of the power grid and impose higher requirements on the grid's resource allocation capability. On the one hand, State Grid Corporation of China has accelerated grid interconnection, strengthened unified dispatch, improved the system's balance and regulation capability and cross-regional and cross-provincial transmission capacity, effectively supporting large-scale development and wide-area allocation of new energy; on the other hand, it has actively promoted research and development of technologies and projects related to new energy power generation grid integration and operation control, and fully promoted the comprehensive development and utilization of new energy.
State Grid Corporation of China has built the world's largest new energy comprehensive utilization project with the most flexible operation mode and the highest comprehensive control level - the Zhangbei National Wind and Solar Storage and Transmission Demonstration Project, integrating wind power, photovoltaic power generation, energy storage, and intelligent transmission, providing a new "Chinese solution" for new energy development. It has built an internationally leading new energy power generation forecasting system, initially achieving predictability, schedulability, and controllability of new energy grid integration. It has built a new energy production simulation system and a new energy optimal dispatch control system, which have been widely applied in provincial and above power grids. It has built and put into operation the world's largest capacity all-vanadium redox flow battery energy storage system, laying a solid foundation for exploring the operation mode and promotion of energy storage systems supporting wind farms. It has led the establishment of a new energy grid integration technical standard system adapted to China's new energy development model and power system characteristics, achieving standardization of the entire process of new energy planning and design, testing and inspection, power forecasting, and dispatch operation, reaching the world's advanced level.
The research and development of new energy grid integration and operation related technologies have greatly alleviated the problem of new energy consumption in China. In 2018, with a 22% year-on-year increase in new energy grid-connected installed capacity, the new energy utilization rate increased by 5.2 percentage points. In June 2017, Qinghai achieved 100% clean energy power supply for 7 consecutive days for the first time; in June 2019, Qinghai's "Green Power 15 Days" innovative practice achieved 360 hours of zero-emission electricity for 15 consecutive days across the province, far exceeding Portugal's record of 4 consecutive days of full clean energy power supply in May 2016, promoting China's energy to take a solid step on the road of clean and low-carbon transition.
IV. Promoting the Deep Integration of Energy Technology and Digital Technology to Boost the New Era of Energy Development to a New Level
