永磁同步电机调速系统滑模抗饱和控制研究

发布时间：2018-08-28 15:57

【摘要】：永磁同步电机具有功率密度高、可靠性高、结构简单和体积小等众多优点,因此在数控机床、工业生产以及船舶工业等众多领域获得了广泛应用,在这些领域中,电机调速发挥重要作用,但是永磁同步电机调速系统是一个存在物理限制和强耦合的复杂非线性的系统,因此要获得高精度、高性能的调速效果需要在考虑电流耦合、系统饱和及系统非线性的基础上对控制算法进行深入研究。滑模控制能够在一定程度上克服系统的非线性并且能够与抗饱和方法有机结合,因此适合用于永磁同步电机的调速控制。首先,对永磁同步电机调速系统中饱和限制恶化系统调速性能(Windup现象)的机理进化分析,并在传统的抗饱和(Anti-reset Windup)方法的基础上进行改进,新方法通过在控制器的积分环节引入指数项增益来削弱系统到达稳态前的积分作用,从而降低饱和限制对系统调速性能的影响,仿真证明该方法能够有效削弱饱和限制对系统调速性能的不利影响。其次,针对滑模控制中抖振对调速系统控制性能的影响,本文首先分析了以指数趋近律为代表的传统滑模控制趋近律在系统趋近速度和抖振水平之间的矛盾,在此基础上设计基于收敛型指数趋近律的滑模抗饱和控制。其次将所设计的趋近律方案与传统的指数趋近律的切换层宽度对比分析可以看出该方法能够有效抑制系统抖振,最后同时该方法还保留了传统指数趋近律响应迅速的优点。通过两类仿真分别验证本文设计的滑模控制和滑模抗饱和控制在电机调速系统中的良好性能。再者,针对滑模控制中切换控制的存在必然导致系统抖振的问题,本文设计了神经网络抗饱和控制,该方法使用神经网络控制代替切换控制从而避免抖振的产生,同时引入并行控制避免神经网络陷入局部收敛,仿真结果表明该方案在永磁同步电机调速系统中既能保留滑模控制响应迅速和调速精度高的优点又能避免系统抖振的产生。最后,通过实验验证本文设计的滑模控制方法的优越性,本文首先介绍了永磁同步电机调速系统的硬件平台和软件流程,接着给出增量式滑模抗饱和控制的数字实现,最后通过启动和调速实验验证了本文算法的动态和稳态性能,并给出算法的时间复杂度对比分析。
[Abstract]:Permanent magnet synchronous motor (PMSM) has many advantages such as high power density, high reliability, simple structure and small size, so it has been widely used in many fields, such as numerical control machine tools, industrial production and ship industry. Motor speed regulation plays an important role, but permanent magnet synchronous motor speed regulation system is a complex nonlinear system with physical limitation and strong coupling. Therefore, in order to obtain high precision and high performance speed regulation effect, current coupling should be considered. On the basis of system saturation and system nonlinearity, the control algorithm is deeply studied. Sliding mode control can overcome the nonlinearity of the system to a certain extent and can be combined with the anti-saturation method, so it is suitable for the speed control of permanent magnet synchronous motor (PMSM). Firstly, the mechanism of saturation limited deterioration (Windup phenomenon) in permanent magnet synchronous motor (PMSM) speed control system is analyzed and improved on the basis of traditional anti saturation (Anti-reset Windup) method. The new method weakens the integral function before the system reaches the steady state by introducing exponential gain into the integral link of the controller, thus reducing the influence of saturation limitation on the speed regulation performance of the system. Simulation results show that the proposed method can effectively reduce the negative effect of saturation limitation on the speed regulation performance of the system. Secondly, aiming at the effect of buffeting on the control performance of the speed regulating system in sliding mode control, this paper first analyzes the contradiction between the system approach speed and the buffeting level of the traditional sliding mode control approach law, which is represented by the exponential approach law. On this basis, a sliding mode anti-saturation control based on convergent exponential approach law is designed. Secondly, by comparing the proposed approach law scheme with the traditional exponential approach law, it can be seen that the proposed method can effectively suppress the chattering of the system, and at the same time, it retains the advantage of fast response of the traditional exponential approach law. Two kinds of simulations are carried out to verify the good performance of the sliding mode control and the sliding mode anti-saturation control in the motor speed control system. Furthermore, in view of the problem that the switching control in sliding mode control will inevitably lead to buffeting, this paper designs a neural network anti-saturation control, which uses neural network control instead of switching control to avoid buffeting. At the same time, parallel control is introduced to avoid the neural network falling into local convergence. The simulation results show that the proposed scheme can not only retain the advantages of fast response of sliding mode control and high precision of speed regulation, but also avoid the chattering of the system in the PMSM speed control system. Finally, the advantages of the sliding mode control method designed in this paper are verified by experiments. Firstly, the hardware platform and software flow of the PMSM speed control system are introduced, and then the digital realization of incremental sliding mode anti-saturation control is given. Finally, the dynamic and steady performance of the algorithm is verified by start-up and speed regulation experiments, and the time complexity of the algorithm is compared and analyzed.
【学位授予单位】：中国科学技术大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM341

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