【作者】 王正齐；

【导师】 刘贤兴；

【作者基本信息】 江苏大学 ， 电力电子与电力传动， 2011， 博士

【摘要】 无轴承异步电机结合了异步电机和磁轴承的特点,既可产生驱动负载的电磁转矩,又能产生支承转子的径向悬浮力,其潜在的应用价值和复杂的运行控制已成为目前高速交流传动领域一个新的研究方向。针对无轴承异步电机非线性、强耦合、多变量的特点,本文在国家自然科学基金(60674095、61174055)等项目的支持下,以无轴承异步电机的非线性解耦控制为研究重点,研究了无轴承异步电机的数学模型、基于转矩绕组转子磁场定向的无轴承异步电机控制方法、基于逆系统方法的无轴承异步电机非线性内模控制策略以及基于支持向量机α阶逆系统方法的无轴承异步电机解耦控制方法,设计了无轴承异步电机的数字控制系统。介绍了无轴承异步电机的结构、实现方法和径向悬浮力的产生原理,推导了径向悬浮力和旋转部分的数学模型,建立了转子运动方程。并通过有限元仿真,证明了所设计的无轴承异步电机结构和性能的正确性。针对无轴承异步电机电磁转矩和径向悬浮力之间的强耦合特性,研究了基于转矩绕组转子磁场定向的无轴承异步电机控制策略。为解决转子磁场定向控制系统转子径向悬浮力之间存在耦合的问题,本文在以往基于转矩绕组转子磁场定向控制的无轴承异步电机系统基础上,加入悬浮控制绕组转子电流的补偿量,使得改进的系统具有更好的悬浮特性。为了实现无轴承异步电机电磁转矩和悬浮力之间的动态解耦控制,本文采用基于逆系统方法的非线性内模控制策略。在运用逆系统方法将无轴承异步电机解耦成转子径向位移、转速和转子磁链四个独立的伪线性子系统后,对伪线性系统引入内模控制策略,保证了控制系统的鲁棒性和抗干扰能力。针对建立无轴承异步电机的精确数学模型比较困难的问题,利用支持向量机来辨识无轴承异步电机的逆模型,并将它串联在原系统之前,接着采用线性系统综合的方法对无轴承异步电机进行复合控制。仿真试验结果表明,支持向量机α阶逆系统方法不仅能够实现无轴承异步电机转速子系统和转子径向位移子系统之间的动态解耦控制,而且较一般的逆系统方法鲁棒性更强,跟踪精度更高。本文设计了以TMS320F2812数字信号处理器为核心的无轴承异步电机数字控制系统,包括硬件电路设计和软件编程。硬件电路设计由主电路、驱动电路、保护电路、检测电路和故障信号处理电路等构成。软件部分则基于无轴承异步电机转子磁场定向控制策略,介绍了数字控制系统的软件结构,并给出了各个程序模块详细的流程图。更多还原

【Abstract】 The bearingless induction motor, which combines characteristics of induction motor and magnetic bearings, can provide both torque and radial suspension forces. The potential value and the complex operation control has become a new research field of the high-speed AC drive. Because the bearingless induction motor is a nonlinear, multi-variable and strong-coupled system, this dissertation focuses on the nonlinear decoupling control of the motor supported by the National Natural Science Foundation under grant 60674095 and 61174055. The mathematical model of the bearingless induction motor, the rotor flux oriented control method for the torque windings and the nonlinear internal model control strategy based on inverse system theory are studied. Besides, the nonlinear decoupling control strategy based on support vector machine (SVM)α-th order inverse system is also proposed, and the digital control system of the bearingless induction motor is designed.The structure, implementation and the principle of the radial suspension force of the bearingless motor is introduced, the mathematical model of the suspension force and the rotation part of the motor is derived, and the motion equations are set up. By finite element simulation, the structure and performance of the bearingless motor are verified.To realize the decoupling control of electromagnetic torque and radial suspension force of the bearingless induction motor, the rotor flux oriented controller for the drive control system is utilized. However, in the control algorithm based on rotor flux orientation of torque windings, coupling still exists between the radial suspension forces. A novel rotor flux oriented control system is proposed in which the rotor currents generated by the suspension control windings are taken into account. So the improved rotor flux oriented control system has better suspension characteristic than the previous one.In this dissertation, a new internal model control (IMC) strategy based on inverse system theory is proposed to realize the dynamic decoupling control between torque and suspension force for bearingless induction motor. Inverse system method is used to decouple the original nonlinear system into four independent pseudo-linear subsystems, that is, two radial displacement subsystems, a speed subsystem and a rotor flux subsystem. Then, the internal model control method is introduced to the four pseudo-linear subsystems to ensure the robustness and anti-jamming ability of the closed-loop system.Since the accurate mathematical description of the bearingless induction motor is difficult to acquire, SVM regression method is used to identify the inverse model of the bearingless induction motor. By cascading the inverse model with the original one, the nonlinear bearingless induction motor system is decoupled. Then, linear control system techniques are applied to the linear subsystems to synthesize and simulation. The results show that the dynamic decoupling control among the speed subsystem and the rotor displacement subsystems can realized by SVMα-th order inverse system. Besides, the SVMα-th order inverse system has better robustness and higher tracking accuracy than the inverse system method.A digital control system for real-time control is designed on DSP (TMS320F2812) which includes hardware design and software programming. The hardware circuits are composed of the the main circuit, the drive circuit, the protection circuits, the test circuits, the fault signal processing circuit and so on. In the software part, based on rotor flux oriented control of the bearingless induction motor, the software architecture of the digital control system is given and the detailed flow charts of all program modules are introduced.更多还原