基于多阶电流谐波抑制的超高真空复合分子泵低损耗控制方法与实验研究

超高真空系统对于国防安全保障、国民经济建设等领域的设备研制至关重要，是提升其整体性能的关键因素。磁悬浮分子泵是超高真空系统的核心部件，高速永磁电机是其动力来源。分子泵的散热条件严苛，电机损耗会增加泵内温升，严重影响分子泵的超高真空性能。为降低电机损耗，本项目针对多阶电流谐波的抑制方法展开研究。首先设计开关霍尔信号的坐标变换，提出霍尔矢量频率检测方法，精确地估算转子位置，实现低损耗的正弦波电流驱动；然后提出位置误差信息重构方法，不依赖电机参数，校正估算的转子位置，抑制位置误差产生的低次谐波；设计一种“二阶-偶次-分数”结构的复合重复控制器，系统的鲁棒性好，收敛速度快，抑制逆变器非线性产生的高次谐波；最后，搭建磁悬浮分子泵测试平台，进行相关实验验证。本项目的研究为降低用于超高真空复合分子泵的高速永磁电机的损耗提供必要的理论基础，同时促进解决应用于其他场景的高速电机谐波抑制的共性科学问题。

Ultra-high vacuum (UHV) system is essential for the development of important components in national defense field, national economic construction, etc. Magnetically suspended composite molecular pump (MSCMP) is the key equipment to obtain the UHV environment, and high-speed permanent magnet motor is the power source of MSCMP. Due to the vacuum environment, the heat cannot be dissipated easily in the MSCMP. The motor loss will produce a large quantity of heat, which can severely reduce the performance of MSCMP. In order to reduce the motor loss, the research of this project is focused on the current harmonic suppression. Firstly, the Hall vector which is related to the position is obtained by the coordinate transformation. The Hall vector frequency tracking is proposed, which can estimate continuous position accurately. The low-loss sine-wave current drive can be realized. Secondly, a high-precision position correction method based on position error reconstruction is proposed. The proposed method is independent of motor parameters, which can reduce the low-order current harmonics caused by position estimation errors. Then, a compound repetitive controller with a second-even-fractional structure is designed. The system has good robustness and fast convergence speed, and the high-order harmonics generated by inverter nonlinearity can be suppressed. Finally, an experimental platform of MSCMP is developed to verify the proposed low-loss control method. This work will provide the necessary theoretical basis for reducing the loss of high-speed permanent magnet motors used for ultra-high vacuum composite molecular pump. It will also promote the settlement of the common scientific issues about harmonic suppression of high-speed motors applied in other fields.