Recently, the scientific and technological achievement of “Modeling and Simulation Theory of Power Electronics Hybrid System and Its Industrial Software and Application” completed by the team of Professor Zhao Zhengming of the Department of Electrical Engineering and Applied Electronics (EEA) of Tsinghua University passed the appraisal of scientific and technological achievement organized by the China Electrotechnical Society. A total of more than 30 people including Professor Zeng Rong, Vice President of Tsinghua University, experts of the appraisal committee, Secretary General Han Yi of China Electrotechnical Society, special guest Academician Han Yingduo, Professor Kang Chongqing, Dean of EEA, and main members of Professor Zhao Zhengming’s team participated in the appraisal meeting online or offline. The meeting was presided over by Liu Miao, director of the Consulting Department of China Electrotechnical Society. The appraisal committee consists of Academician Cheng Shijie of Huazhong University of Science and Technology, Academician Luo An, Director of National Electric Power and Control Engineering Technology Research Center of Hunan University, Academician Rao Hong, Chairman of China Southern Power Grid Research Institute Co., Ltd., Academician Wang Guoqing, Chief Information Officer of China Aerospace Science and Technology Corporation, Professorate Senior Engineer Xiao Xiangfeng, Executive Vice Chairman of Power Electronics Branch of China Electrical Equipment Industry Association, Professorate Senior Engineer Li Chongjian of Metallurgical Automation Research and Design Institute, Professor Xu Dehong, Director of Institute of Power Electronics Technology of Zhejiang University, Researcher Li Yaohua, Director of Institute of Electrical Engineering, Chinese Academy of Sciences, and Professorate Senior Engineer Sun Huadong, Vice President of China Electric Power Research Institute.

Appraisal committee composed of nine experts

Participants

At the appraisal meeting, Professor Zeng Rong, Vice President of Tsinghua University, delivered a speech. He pointed out that power electronics equipment has become one of the most critical electrical equipment for China’s power energy transformation under the dual carbon goal, and the industrial simulation software is the most important and basic tool to support system analysis and design. With the support of a series of national major projects such as the National Natural Science Foundation of China, the team led by Professor Zhao Zhengming has carried out continuous and in-depth basic research, overcome the theoretical problem of modeling and simulation of power electronics hybrid systems, and developed a completely independent power electronics industry simulation software, which is of strategic significance for the development of China’s power and energy industry.

Zeng Rong, Vice President of Tsinghua University, delivered a speech

Professor Zhao Zhengming and members of the project team made work reports and technical reports respectively, read out the test report, novelty search report and application and economic benefit report, and reported the project details to the appraisal committee comprehensively. After questioning and discussion, the experts of the appraisal committee agreed that: “This project has achieved significant original scientific research results, realized the basic theoretical breakthrough and independent innovation of industrial simulation software in the field of power electronics in China, and is leading the multi-temporal dynamics of power electronic systems, and the technology of the project is internationally advanced.”

Special guest Academician Han Yingduo also spoke highly of the project result. He pointed out that it is necessary to seize the national strategic opportunity of building a new type of power system, vigorously develop independent and controllable industrial simulation software in the field of power electronics systems, and further strengthen interdisciplinary and academic cooperation on the basis of existing achievements so as to realize generalized application in more fields. Professor Kang Chongqing, Dean of EEA, expressed thanks on behalf of the project completion unit, thanked the experts for their high recognition of the project results and their valuable guidance, and thanked the China Electrotechnical Society for organizing this appraisal meeting.

Kang Chongqing, Dean of EEA of Tsinghua University, expressed thanks

Power electronics has become a major demand and underlying support in key fields such as global new power systems, electric traction, and the defense industry. Among them, industrial simulation software is the most important basic tool to support system analysis and design. However, the existing modeling and simulation methods are based on time discrete and time drive, modeling and solving the nanosecond-level switching process is diverged, and cannot recognize the system failure caused by the switching transient, which brings serious hazards such as device burnout and system collapse; meanwhile, the simulation of large-scale power electronics systems often takes hours or even days, the time consumed can only be shortened by simplifying the equivalence, and the simulation results cannot represent the limit application boundary of the system. All of these lead to over-reliance on margin design for the safe and reliable operation of the device, which seriously restricts product performance and economy.

In the face of the above-mentioned theoretical problems and major demands, the project team has condensed the key scientific problem of “multi-time scale dynamical characterization of power electronics hybrid systems”, and took the lead in undertaking the first major project of the National Natural Science Foundation of China in the field of power electronics. After nearly ten years of continuous and in-depth basic research, it finally broke solve the above-mentioned major theoretical problems, created the modeling and simulation theory of power and electronics hybrid systems, and originally proposed a new simulation cognitive idea of “discrete state and event-driven", formed a “multi-time scale segmental analytical modeling”, “decoupled discrete state event-driven simulation solution” and “semi-symbolic state equation computer sparse generation” integrated technical system.

Based on the above theoretical innovations, the project team innovatively developed the world first state-discrete-based power electronics industry simulation software, which has passed the third-party test of the CESI. Compared with other internationally advanced software, the calculation speed is increased by two orders of magnitude on average, there is no divergence problem, and it is above the relevant national standards. As an industrial software with independent intellectual property rights, it has been applied by more than 50 key units in China and more than 200 institutions in 15 countries such as the United States and Japan, returning wide recognition and significant economic and social benefits from home and abroad.

DSIM software interface

Innovation achievement 1: Created a multi-time scale segmented analytical modeling method

Aiming at the modeling and characterization of multi-time scale process of power electronics hybrid systems, a multi-time scale segmented analytical modeling method was created, which has broken through key technologies such as modeling parameter acquisition, realized switching transient mechanism decoupling and dynamic parameter decoupling, and solved the problem of limit cognition and characterization of dynamic behavior of power electronics systems.

Innovation achievement 2: Created a decoupled discrete-state event-driven simulation method

Aiming at the simulation solution of multi-time scale process of power electronics hybrid system, a theoretical method of multi-time scale state-discrete and event-driven simulation is originally proposed, which has overcome the problem of matching time step with multi-time scale behavior and the problem of simulation divergence, and improved the simulation solution speed effectively.

Innovative achievement 3: Created a semi-symbolic equation computer sparse generation method

Aiming at the computer automation realization of industrial simulation software of power electronics hybrid system, a semi-symbolic equation computer sparse generation method is proposed, which has significantly reduced the calculation time of automatic generation of numerical equation for power electronics systems; and the world first state-discrete power electronics industry simulation software was developed.