Recently, China Society of Electrical Engineering (CSEE) held a technical appraisal meeting for the project "research and development of 4500V/5000A IGCT-Plus key technologies and devices for DC power grid" in Zhuzhou. The 4500V/5000A IGCT-Plus device for DC power grid developed by Tsinghua University and Zhuzhou CRRC Times Electric Co., Ltd. (hereinafter referred to as "CRRC Times Electric") has passed the appraisal successfully, marking that the new generation of domestic large capacity IGCT device has transferred from technology research and development, process manufacturing, test and verification to engineering application.

The Expert Committee is composed of 10 authoritative experts from government, enterprises, scientific research institutes and universities, including Academician Zhou Xiaoxin of Chinese Academy of Sciences (CAS) and Academician Luo An of Chinese Academy of Engineering (CAE). More than 30 participants, including Academician Ding Rongjun of CRRC Zhuzhou Electric Locomotive Research Institute Co., Ltd., Feng Jianghua, deputy general manager, Prof. Zeng Rong, associate professors Yu Zhanqing and Zhao Biao of the EEA, Tsinghua University, General Manger Liu Kean and Deputy GM Shang Jing of CRRC Times Electric, Wu Yudong, general manager of the Semiconductor Business Department, attended the technical appraisal meeting.

Prof. Zeng Rong and associate Prof. Zhao Biao respectively made work report and technical report, and comprehensively reported the project situation to the Appraisal Committee. The project team composed of Tsinghua University and CRRC Times Electric has been working together for many years to tackle key problems. It has established a compact physical mechanism model of GCT chip, proposed parameter optimization and performance regulation methods, improved the key preparation process, and put forth a new gate drive scheme. First of all, it has successfully developed a new generation of IGCT-Plus device for DC power grid. The device has a turn-off current of 5000A, a DC continuous current of 3000A, a 10ms surge current capacity of 35ka, and a di/dt withstand capacity of 500Hz 5000A/us. It has the functions of black start and over-current protection, and can realize the energy conversion of DC power grid with low cost, high efficiency and high reliability.

Experts of the Appraisal Committee listened to the reports of the project team, tested the performances of IGCT-Plus device such as DC continuous flow, critical rise rate of voltage and current, over-current protection, black start, surge current, failure short circuit, etc., and questioned and discussed with members of the project team to promote the national production of high-voltage and large capacity semiconductor devices and DC power grid equipment. The work done is highly affirmed, and it is suggested to be popularized and applied in more practical projects. After discussion, experts of the Appraisal Committee agreed that the project solved the scientific and technical problems affecting the popularization and application of IGCT in the field of power grid. After testing and application verification, the 4500V/5000A IGCT-Plus device for DC power grid developed by the project team has reached the international leading level in mechanism model, performance control method, and gate drive.

With the rapid development of wind energy, solar energy and other new energy and large-scale energy storage, there is a huge market scale of flexible DC power transmission and distribution system in the world. The existing international flexible DC converter equipment basically adopts IGBT scheme. However in fact, unlike the power electronic equipment of AC power grid, the MMC and other key equipment in DC power grid have many new features, largely avoiding the key bottleneck of low operating frequency of IGCT, bringing many potential advantages, such as low cost, high reliability and high efficiency, and great application potential. From the aspects of physical mechanism model, doping design and performance control, preparation process and gate drive, this project has overcome the key problems such as voltage and current rise rate, black start, and driving power management, which affect the application of IGCT in the field of power grid, and is expected to effectively improve the technical economy of flexible transmission.

The IGCT-Plus device developed in this project can be applied in MMC, DC circuit breaker, DC transformer, DC energy dissipation device and other DC power grid key equipment, and also has application prospect in high-voltage and large capacity SVG and other flexible AC power transmission equipment, promoting large-scale collection of new energy, regional flexible power grid transmission interconnection and safe and stable operation of power grid, and promoting high-voltage and large capacity semiconductor device. The localization of components and flexible transmission equipment supports the clean transformation of China's energy structure and energy consumption revolution.

Reprint statement: Transferred from "Tsinghua Energy Internet Research Institute" (WeChat public number)