BLDCM系统中逆变器故障容错拓扑结构与控制方法研究

发布时间：2018-04-30 03:14

本文选题：无刷直流电机 + 直接转矩控制　；参考：《河北工业大学》2014年博士论文

【摘要】：永磁无刷直流电机在生产实践中具有广泛的应用。但还有一些问题亟待解决和完善，如无位置传感器控制，转矩脉动抑制和容错控制等；以上问题限制了无刷直流电机控制性能的进一步提高，阻碍了它在高精度、高可靠性要求场合的应用。因此，本文在总结和借鉴前人研究成果的基础上，以提高三相无刷直流电机驱动系统的运行可靠性和降低转矩脉动为目标，针对无刷直流电机驱动系统中逆变器的故障拓扑结构和控制策略开展了以下方面的研究：首先，针对目前六开关逆变器无刷直流电机直接转矩控制中存在的问题，以及无位置传感器控制方法中转子位置的检测方法进行了详细的分析。根据以上分析，提出了一种基于单神经元自适应PID的无刷直流电机无位置传感器直接转矩控制。该方法通过采用一种基于单神经元自适应PID的方法，建立了两相静止坐标系下的反电势和磁链观测器，进而实现了无刷直流电机的直接转矩控制。通过Lyapunov稳定性分析方法实现了观测器稳定性的证明。并给出了神经元比例系数的在线调整方法，补偿了由于定子电压计算不准确而引起的磁链和转矩的估计误差。其次，通过对目前六开关逆变器故障拓扑后的四开关逆变器无刷直流电机控制系统中存在的问题的分析，提出了一种新的、可行的四开关逆变器电压空间矢量调制方法和最优开关选择表，提出了一种四开关逆变器无刷直流电机的磁链观测方法，，进而实现了四开关逆变器无刷直流电机的无位置传感器直接转矩控制。该观测器中不含有速度参数，速度的变化对控制系统的影响较小，尤其是在低速时运行效果良好；利用Lyapunov稳定性分析方法证明了该观测器的稳定性。给出了一种新的定子电阻在线估计和直流母线电压在线补偿方法，以上方法可显著削弱定子电阻变化和定子电压计算不准确对系统控制效果产生的影响。再次，由于四开关逆变器的电压利用率仅为六开关逆变器电压利用率的一半，若采用四开关逆变器直接驱动逆变器故障后的无刷直流电机将影响其正常的工作状态，为了增加逆变器的输出能力应提高直流链电压以保证电机的工作状态不变。为此，提出一种新型的Z源网络拓扑结构为六开关逆变器故障拓扑后的四开关逆变器提供足够高的直流链电压。详细分析了SL-Γ-Z源逆变器的运行特性，与传统Z源逆变器和SL-Z源逆变器进行了对比分析，重点分析了电容电压应力和电感电流应力；提出了一种SL-Γ-Z源并网逆变器的单周期控制方法，并进行了必要的稳定性分析和提高。最终，基于前面各章节的分析，为使六开关逆变器故障后不影响无刷直流电机的正常运行，提出了采用SL-Γ-Z源逆变器驱动无刷直流电机的拓扑结构和控制方法。研究了四开关SL-Γ-Z源逆变器的电压空间矢量调制方法；给出了系统的拓扑结构和抑制Z源网络中电感电流断续引起问题的电路结构；给出了一种四开关SL-Γ-Z源逆变器驱动无刷直流电机的转矩控制方法。
[Abstract]:Permanent magnet brushless DC motor is widely used in production practice, but there are still some problems to be solved and perfected, such as non position sensor control, torque ripple suppression and fault-tolerant control. The above problems restrict the further improvement of the control performance of the brushless DC motor and obstruct it in high precision and high reliability requirements. Therefore, on the basis of summarizing and drawing on the achievements of previous research, this paper aims at improving the operation reliability of the three-phase brushless DC motor drive system and reducing the torque ripple, and studies the following aspects of the fault topology and control strategy of the inverter in the brushless DC motor drive system.
Firstly, the problems existing in the direct torque control of the brushless DC motor of the six switching inverter and the detection method of the rotor position in the sensorless control method are analyzed in detail. Based on the above analysis, a kind of direct torque of the sensorless DC motor based on single neuron adaptive PID is proposed. Control. By using a single neuron adaptive PID method, the back EMF and flux observer in the two phase stationary coordinate system are established, and the direct torque control of the brushless DC motor is realized. The stability of the observer is proved by the Lyapunov stability analysis method, and the ratio coefficient of the neuron is given. The online adjustment method compensated the estimation error of flux linkage and torque caused by inaccurate calculation of stator voltage.
Secondly, by analyzing the problems existing in the brushless DC motor control system of the four switched inverter after the six switched inverter topology, a new and feasible voltage space vector modulation method and the optimal switch selection table for the four switching inverter are proposed, and a magnetic chain of the brushless DC motor with four switching inverters is proposed. In this observer, the sensorless direct torque control of a brushless DC motor of four switching inverter is realized. The observer does not contain speed parameters, and the change of speed has little influence on the control system, especially at low speed. The stability of the observer is proved by the Lyapunov stability analysis method. A new method of on-line estimation of stator resistance and on-line compensation for DC bus voltage is presented. The above method can greatly weaken the influence of stator resistance change and inaccurate calculation of stator voltage on the control effect of the system.
Thirdly, because the voltage utilization rate of the four switching inverter is only half of the voltage utilization rate of the six switch inverter, the brushless DC motor which uses the four switching inverter to directly drive the inverter will affect its normal working state. In order to increase the output capacity of the inverter, the DC chain voltage should be increased to ensure the working condition of the motor. For this reason, a new type of Z source network topology is proposed to provide high DC link voltage for the four switch inverter after the six switch inverter topology. The operation characteristics of the SL- gamma -Z source inverter are analyzed in detail, and the comparison analysis is made with the traditional Z source inverter and the SL-Z source inverter, and the capacitor voltage stress is emphatically analyzed. And the inductor current stress, a single cycle control method of SL- gamma -Z source grid connected inverter is proposed, and the necessary stability analysis and improvement are carried out.
Finally, based on the analysis of the previous chapters, in order to make the six switching inverter fail to affect the normal operation of the brushless DC motor, the topology and control method of using the SL- gamma -Z source inverter to drive the brushless DC motor is proposed. The voltage space vector modulation method of the four switch SL- gamma -Z source inverter is studied. The circuit structure of the problem is caused by the discontinuation of the inductance current in the Z source network, and a torque control method for the brushless DC motor driven by the four switch SL- gamma -Z source inverter is given.

【学位授予单位】：河北工业大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：TM464

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