电磁轴承数字控制系统设计

【作者】 毛智伟；

【导师】 祝长生；

【作者基本信息】 浙江大学 ， 电机与电器， 2006， 硕士

【摘要】 主动电磁轴承(Active Magnetic Bearing)是一种利用可控电磁力将转子悬浮起来的新型轴承，具有无摩擦、无污染、长寿命等传统轴承无法比拟的优点。它是一个典型的机电一体化系统，包括电气控制系统(传感器、功率放大器、控制器)和机械系统(电磁轴承定子、转子、执行线圈)，其性能的好坏主要取决于电气控制系统的性能。本文以主动电磁轴承的控制器和功率放大器为研究对象，对其进行了深入的研究。本文首先介绍了电磁轴承系统的组成和原理，对其各部分功能进行了分析，建立了单自由度电磁轴承系统的数学模型，并利用MATLAB对其特性进行了仿真。接着讨论了电磁轴承的开关功率放大器，对其拓扑结构、调制方法、控制方式等做了分析。详细介绍了本文设计的两电平和三电平PWM开关功放的电路结构、控制电路、效率和纹波等，对功放的特性进行了仿真并测试了其性能。然后介绍了电磁轴承数字控制系统的结构，分为硬件和软件两方面对其进行了详细的阐述。硬件设计方面主要包括微处理器的选择、传感器滤波电路、DAC连接、DSP外设接口等，软件设计包括包括控制策略的选择、PID数字算法的推导、控制算法的程序实现等。最后对电磁轴承系统各部分进行了联合调试，成功完成了四个自由度的静态和动态悬浮，实验结果表明系统起浮平稳，阻尼合适，在大范围内稳定性好，能满足电磁轴承系统运行要永，论文所做的工作达到了预期的目标。更多还原

【Abstract】 Active magnetic bearings (AMB), which use the controllable attractive force of electromagnets to maintain a rotating ferromagnetic body contact-free in its nominal position, have seriously developed in the rotating machinery; provide numerous advantages compared with the conventional bearings, such as: no contact, no wear, no lubrication, long life and controllable dynamic characteristics etc.AMB is a typical mechatronic system, which includes electric subsystem (including sensors, controller and power amplifier) and mechanical system (including rotor, stator and coil). The performance of the AMB system is mainly determined by the electric control system. This paper is focuses on the controller and power amplifier of the AMB.First the structure and theory of the AMB system are introduced, the model of a single degree-of-freedom AMB is built, and its performance is simulated through MATLAB Simulink. Then the circuit topology, control method and modulation technique of the power amplifier are discussed. Two PWM based current control switching power amplifiers with two and three level are designed and tested. The digital controller of AMB and several control stratagems are proposed and discussed, the PID control arithmetic is chosen to realize the control function. At last, the whole ABM system is debugged, and the suspension of 4 degree-of-freedom is realized in the experiment.更多还原