Exterior view of laboratory in Engineering Building

Laboratory inside

National "Twelfth Five-Year" scientific and technological innovation achievement exhibition stand

Multi-bearing experimental rig

Megawatt-class magnetic bearing high-speed permanent magnet motor

High and low-temperature test chambers

Papers

[1] Bian, X., Shi, Z., Sun, Z., Zhao, J., Liu, X., Yan, X., Mo, N. (2024). Synchronous disturbance suppression of active magnetic bearing rotor systems using variable period adaptive control algorithm. Measurement Science and Technology, 35(1).

[2] Bian, X., Shi, Z., Sun, Z., Shi, L., Yan, X., Mo, N. (2023). Automatic Balancing for AMB-Rotor System Using Adaptive Period Iteration Control with a Novel Rotating Speed Estimator. IEEE Sensors Journal, 23(15), 17173-17186.

[3] Yan, X., Liu, Y., & Zhang, C. (2022). Multiresolution Hypergraph Neural Network for Intelligent Fault Diagnosis. IEEE Transactions on Instrumentation and Measurement, 71, 1-10.

[4] Zhang, X., Sun, Z., Zhao, L., Yan, X., Zhao, J., Shi, Z. (2021). Analysis of supercritical pitchfork bifurcation in active magnetic bearing-rotor system with current saturation. Nonlinear Dynamics, 104(1), 103-123.

[5] Sun, Z., Zhang, X., Fan, T., Yan, X., Zhao, J., Zhao, L., Shi, Z. (2019). Nonlinear dynamic characteristics analysis of active magnetic bearing system based on cell mapping method with a case study. Mechanical Systems and Signal Processing, 117, 116-137.

[6] Yan, X., Sun, Z., Zhao, J., Shi, Z., & Zhang, C. (2019). Fault diagnosis of rotating machinery equipped with multiple sensors using space-time fragments. Journal of Sound and Vibration, 456, 49-64.

[7] Zhao, J., Sun, Z., Yan, X., Yang, G., Zhou, Y., Liu, X., Zhang, X. (2018). Helium blower test based on aerodynamic force simulation. Annals of Nuclear Energy, 118, 283-290.

[8] Zhao, Y., Liu, X., Yang, G., Shi, Z., & Zhao, L. (2018). Dynamic Analysis for the Rotor Drop Process and Its Application to a Horizontal Rotor-Active Magnetic Bearing System in Helium Gas. Journal of Tribology, 140(4).

[9] Liu, X., Shi, Z., Yang, G., & Yan, X. (2017). Experimental study on breakdown voltage of high pressure and high temperature helium gas between parallel electrodes. Annals of Nuclear Energy, 110, 1224-1231.

[10] Zhao, Y., Yang, G., Liu, X., Shi, Z., & Zhao, L. (2016). Research on dynamics and experiments about auxiliary bearings for the helium circulator of the 10 MW high temperature gas-cooled reactor. Annals of Nuclear Energy, 95, 176-187.

Main Research Achievements

1）Helium Circulator Engineering Prototype

The primary objective of the "High-Temperature Gas-Cooled Reactor Project" is to construct a 200 MW high-temperature reactor nuclear power demonstration plant with independent intellectual property rights. This demonstration plant represents the inaugural commercial-scale industrialization of high-temperature gas-cooled reactor technology in China. The helium circulator stands as a pivotal rotating machinery component necessitating bearings with high availability and reliability. Although foreign-imported magnetic bearings currently fulfill the requirements of the helium circulator, they are costly and fall short in terms of performance and service. As magnetic bearings constitute a crucial "bottleneck" technology, expediting the localization of magnetic bearings for the helium circulator is imperative.

Under the support of a national major project, the Division of Magnetic Bearing Technology at Tsinghua University conducted in-depth research and development on several core technologies of magnetic bearings tailored to the structure, functionality, and operational requirements of the primary helium circulator for the High-Temperature Gas-Cooled Reactor Nuclear Power Plant (HTR-PM). This research encompassed various key technologies, including active vibration suppression control technology for magnetic bearings, complex dynamics of the bearing-rotor system, real-time online monitoring and fault diagnosis technology, on-site electromagnetic compatibility analysis, auxiliary bearing design, and overall system reliability.

Utilizing small-scale test benches and full-scale engineering prototypes, the performance and reliability of independently developed magnetic bearings, controllers, sensors, power amplifiers, and other critical equipment were comprehensively evaluated. Through systematic optimization improvements, standardized design, and process solidification research, a thorough understanding of the core technologies of magnetic bearings, spanning from engineering design and manufacturing to testing, debugging, and operational maintenance, was achieved. This culminated in the validation of product commercialization, enabling the domestic production of magnetic bearings to replace foreign imports for the primary helium circulator of high-temperature gas-cooled reactor nuclear power plants. This achievement marked a significant breakthrough in domesticating the use of magnetic bearings for primary helium circulators in high-temperature gas-cooled reactor nuclear power plants and provided a technical foundation for the smooth implementation of demonstration projects. The project was recognized as one of the "Top Ten Scientific and Technological Advancements in Universities" by the Ministry of Education in 2014.

2）Helium Turbine Compressor

In the "High-Temperature Gas-Cooled Reactor Helium Turbine Power Generation System" (HTR-10GT), the helium turbine compressor operates in a high-temperature sealed environment with helium. The rotor of the turbine unit needs to surpass two flexible critical speeds to achieve the operational speed of 15,000 r/min. Traditional bearings struggle to meet the support requirements of large, heavily loaded, high-speed flexible rotors in the unique environment of the primary loop of a nuclear reactor. Therefore, the utilization of magnetic bearings for support is considered the only feasible solution. As magnetic bearings represent an emerging technology, examples of their application in large-scale engineering projects are limited both domestically and internationally, with no precedent in the field of nuclear energy. To ensure the safe and reliable operation of the helium turbine rotor and its smooth passage through the second-order flexible critical speed, a series of corresponding theoretical and experimental studies need to be conducted extensively.

Currently, only a few countries have completed subcritical tests under laboratory conditions, and surpassing the second-order flexible critical speed in large-scale engineering applications remains unexplored territory.

The Division of Magnetic Bearing Technology at Tsinghua University has brought together talents from various disciplines such as structural design, rotor dynamics analysis, system identification, automatic control, sensors, and power electronics to overcome the challenge of surpassing the second-order critical speed of flexible rotors under controllable conditions. This effort has resulted in the successful design and prototype development of the helium turbine magnetic bearing system.

3）Automatic Detection Technology for Magnetic Bearings

As an integral part of mechanical integrated equipment, magnetic bearings require detection of electrical characteristics and mechanical structures during maintenance. Among these, insulation detection and gap detection are two major testing items. Currently, widely used testing methods involve dismantling for manual measurement, resulting in significant errors and inability to meet the rapid and accurate detection requirements during on-site test in nuclear power plants. Significantly shortening the maintenance time, reducing costs, improving detection accuracy, and robustness of test results are of vital significance for the engineering application of magnetic bearings.

The Division of Magnetic Bearing Technology at Tsinghua University has independently developed automatic detection technology for magnetic bearings. This technology eliminates the need for dismantling and can automatically detect the insulation status of magnetic bearings without affecting the existing main wiring of the bearings. It also enables one-click, multi-channel rapid gap detection without additional sensors, with an error accuracy controlled within 5%. This fully meets the engineering requirements. Collaborating with the China Nuclear Power Technology Research Institute of China Huaneng Group, this technology has been applied to demonstration power plants of high-temperature gas-cooled reactors, with over 10 invention patents filed.

Shi Zhengang

shizg@tsinghua.edu.cn

Division Head

Yang Guojun

yanggj@mail.tsinghua.edu.cn

Mo Ni

moni@tsinghua.edu.cn

Liu Xingnan

liuxingnan@tsinghua.edu.cn

Zhao Lei

zhaolei@tsinghua.edu.cn

Sun Zhe

sun_zhe@mail.tsinghua.edu.cn

Yan Xunshi

yanxs@tsinghua.edu.cn

Zhao Jingjing

Zhao-jj@tsinghua.edu.cn

Zhou Yan

zhou-yan@tsinghua.edu.cn

Zhang Limin

zlm07@mail.tsinghua.edu.cn