高速磁悬浮电机能量转换反激变换器单周期自适应逆控制方法研究

It will result in the instability of high-speed rotor and damage system severely when the power of magnetically suspended motor suddenly is broken off or shut down at high speed.The key to guarantee the safe operation of magnetic bearing is to maintain the stability of high-speed flexible rotor system by supplying continuously electrical energy for magnetic bearing and its control system timely from the regenerative braking energy of motor. Some factors will affect the robustness and dynamic response characteristics of the system seriously, such as the wide range change of power converter relative to input, the strong nonlinearity of the converter and load， the multi-source disturbances of magnetic bearing load and so on. Based on a novel mechanism analysis of large-signal dynamic model for the flyback convertor of energy conversion, this project will study the key factors which influence the dynamic characteristics and stability of the system. Considering the combined effects of multi-source disturbances, time-varying and strong nonlinearity, a robust one-cycle high-dynamic adaptive inverse system control method will be studied in the project. Considering the mutation of load or load power and parameter perturbation, the system model reconstruction and parameter identification will be carried out and large-signal dynamic model is going to be established. The key is to break through the inverse control method for flyback converter, and then a robust single-cycle adaptive inverse control law will be designed. A set of complete robust one-cycle high-dynamic adaptive inverse controller design method will be presented, whose effectiveness and feasibility will be verified by comprehensive experiments. The project will provide a necessary theoretical foundation and technical support for the safe and stable operation of magnetically suspended high-speed power machinery such as magnetically suspended molecular pump, energy storage flywheel and so on.

磁悬浮轴承支承的电机高速旋转时突然停、断电将导致高速转子失稳，使系统严重损坏。断电瞬间将电机的动能快速转化为电能供给磁轴承及其控制系统，使高速磁悬浮柔性转子稳定悬浮是磁轴承安全运行的关键。变换器的大范围输入、变换器和负载的强非线性以及磁轴承负载的多源扰动，严重影响系统的鲁棒性和快速动态响应。本项目立足于一种新颖的能量转换反激变换器系统大信号动态模型，分析影响系统动态特性和稳定性的关键因素，研究系统在变换器和负载多源扰动、时变、强非线性综合作用下的高动态单周期自适应逆控制方法：考虑负载突变和参数摄动情况下，进行系统模型重构和参数辨识，建立系统的大信号动态模型；重点突破反激变换器逆控制方法，设计单周期自适应逆控制律，给出完整的高动态单周期自适应逆控制器设计方法，通过综合实验验证有效性和可行性，为磁悬浮分子泵、磁悬浮储能飞轮等高速动力机械的的安全稳定运行提供必要的理论基础和技术保障。

磁悬浮高速电机与普通机械轴承电机相比具有无摩擦，无需润滑，可主动振动控制等优势，但是需要持续的电力来提供电磁力来支承转子。磁悬浮电机高速旋转时突然停、断电将导致高速转子失稳跌落在保护轴承上，会对磁轴承带来损害，同时破坏转子动平衡。断电瞬间将电机的动能转换为电能供给磁轴承及其控制系统，实现电力失效补偿，这是磁轴承系统安全稳定运行的关键。虽然UPS系统在电力失效时能提供电源补偿，但是UPS系统会大幅提升系统成本，同时对于环境要求较高，限制了其在磁悬浮电机中的应用。而能量转换时所使用的数字变换器，具有输入范围大、变换器是强非线性以及磁轴承负载是多源扰动的特点，严重影响了系统的鲁棒性和快速动态响应。.本项目围绕主动磁轴承支承的高速电机的电力失效补偿问题,首先分析了转子动能至控制系统供电的转换机理，针对数字开关变换器在负载多源扰动、时变、强非线性综合作用下进行信号建模，研究了一种非线性的数字开关变换器控制方法，以提高系统的动态响应能力；其次，针对磁轴承系统负载进行建模与控制研究，同时针对其非线性特性，进行了系统辨识方法的研究；另外，研究了一种新型高效的电机能量回馈方法，解决了现有方法仅适应于PWM驱动方式的问题，并且提高了整个能量回馈过程的效率，降低了转子跌落时的转速，减少了对转子和保护轴承的损坏；最后，提出了一种与电机驱动结构无关的磁轴承电力失效补偿方法，采用主动反电动势控制提高能量转换的效率，对相关设计均进行了仿真分析与实验验证。本项目共发表论文17篇，其中SCI收录13篇，所提出的电力失效补偿方法，提高了系统可靠性和能量转换效率，已应用于超高真空大抽速两类磁悬浮复合分子泵的研制，填补了国内在该技术领域的空白。