磁轴承变饱和柔性变结构控制

采用磁轴承取代传统机械轴承,可消除飞轮储能装置机械摩擦,提高转子临界转速.针对磁轴承控制系统响应快、运行稳定的要求,设计了一种变饱和柔性变结构控制器.根据磁轴承的基本结构与悬浮力模型,建立了系统的状态方程;通过有限元仿真,分析了磁轴承耦合性,确定了系统基本控制方案;将柔性变结构和变饱和项结合,当系统存在较大偏差时只通过线性控制器调节,在中等偏差时通过线性控制器和变饱和状态控制器一起调节,在小偏差时由线性控制器和变饱和状态控制器转变的线性控制器一起调节.仿真与实验结果表明,变饱和柔性变结构控制满足实时控制的要求,磁轴承控制系统具有较快的响应速度和较高的运行稳定性.

Variable saturation soft variable structure control of magnetic bearing

Using the magnetic bearing to replace the mechanical bearing can eliminate the mechanical friction and increase the critical speed of a flywheel energy storage system (FESS). In this paper, the variable saturation soft variable structure (VSSVS) is applied to realize fast response and stable operation of the FESS. According to the basic structure of the magnetic bearing, an equivalent magnetic circuit method is applied to develop the mathematical model of suspension force and the state-space equation. Based on finite element analysis, the coupling characteristics are analyzed and the basic control scheme of the system is established. For the large state vectors, a linear control is employed to regulate, for the moderate state vectors, the nonlinear component is blended into the control signal and for the small state vectors, the nonlinear component becomes linear component, and regulation is accomplished employing two linear controllers. The results show that the VSSVS controller meets the control requirements of the magnetic bearing system.