【作者】 王琦；

【导师】 余海涛；

【作者基本信息】 东南大学 ， 电气工程， 2020， 博士

【摘要】 永磁同步电机在航空航天、数控机床和新能源汽车等领域得到了广泛的应用。然而,永磁同步电机驱动系统是一个强耦合、非线性的系统。为了提升永磁同步电机驱动系统的控制性能,本文分别从降低算法时间复杂度、提高系统稳态性能和系统的容错能力以及增强系统鲁棒性等方面展开了相关研究,分别提出了具体的解决方案,具有相关的理论贡献和工程研究价值。首先,建立了基于三电平NPC逆变器的永磁同步电机驱动系统数学模型,并针对传统调制模型预测控制方法算法复杂,难以在低成本处理器运行的问题,提出了一种改进低复杂度调制模型预测控制方法,该方法采用预测电压方程代替传统方法的预测电流方程,有效降低了算法的时间复杂度。并对基于预测电压方程的改进调制模型预测控制方法和基于预测电流方程的传统调制模型预测控制方法的等效性进行了证明。为了提高传统方法的稳态性能,采用伏秒平衡原理计算合成矢量的占空比,有效降低了传统调制模型预测控制方法的电流总谐波失真。其次,针对传统调制模型预测控制方法开关时间占空比计算不准确的问题进行理论分析,提出了一种值函数求解最优占空比调制模型预测控制方法,该方法通过对预测电压矢量和合成电压矢量之间差的平方和来定义值函数,通过对值函数求偏导数,可以得到合成矢量的最优开关时间占空比,有效提高了永磁同步电机电流环的控制性能。同时,为了在高采样频率下和传统的有限集模型预测控制方法和调制模型预测控制方法进行对比,对传统有限集模型预测控制方法和调制模型预测控制方法进行了改进,有效缩短了程序的运行时间,使这两种方法可以在高采样频率下运行。再次,为了增强永磁同步电机驱动系统故障容错能力,提出了一种逆变器单相故障容错调制模型预测控制方法。硬件采用八开关三相逆变器重构拓扑,并推导了基于该重构拓扑的容错调制模型预测控制方法,使永磁同步电机驱动系统三电平NPC逆变器出现单相故障后,仍可以正常运行,增强了永磁同步电机驱动系统的故障容错能力。同时,在八开关三相逆变器重构拓扑上将所提出的方法和传统有限集模型预测控制方法进行了对比研究,验证了所提出方法的有效性。最后,为了增强永磁同步电机驱动系统的鲁棒性,对永磁同步电机的速度环进行建模,理论分析了永磁同步电机的扰动对系统整体性能的影响,提出了一种改进趋近律调制模型预测滑模复合控制方法。该方法内环采用模型预测控制方法,外环采用一种基于分段函数改进滑模趋近律和扰动转矩观测器相结合的速度环控制方法,通过使用转矩观测器对观测到的外部负载转矩进行前馈,补偿扰动对系统整体性能的影响。并采用李雅普诺夫理论对所提出速度环方法的稳定性进行了证明。所提出的方法有效解决了传统滑模控制方法抖振和趋近速度之间的矛盾问题,提高了系统的整体鲁棒性。更多还原

【Abstract】 Permanent magnet synchronous motor(PMSM)has been widely used in aerospace,numerical control machine tool and renewable energy automobile.However,the PMSM drive system is a strong coupling and nonlinear system.In order to improve the control performance of PMSM drive system,this dissertation puts forward specific solutions from reducing time complexity,improving steady state performance,enhancing fault tolerant ability and robustness of PMSM driver system,respectively.This dissertation has relevant theoretical contributions and engineering research values.Firstly,basic mathematical model of PMSM drive system based on three-levels neutral point clamped inverter is established.Advantages and disadvantages of conventional finite control set model predictive control method and modulated model predictive control method are analyzed.In order to overcome disadvantages of conventional modulated model predictive control method,which is complicated and is difficult to run in low cost processor,an improved low complexity modulated model predictive control method is proposed.The proposed method adopts predictive voltage equations instead of predictive current equations,which can reduce the time complexity effectively.The equivalence of modulated model predictive control method based on voltage equations and conventional modulated model predictive control method is proved by mathematical method.To improve the steady state performance,the dwell times of the synthesis vector are calculated by using the traditional volt-second balance principle,which reduces total harmonic distortion of currents effectively.Secondly,the problem of inaccurate calculation of dwell times in conventional modulated model predictive control method is analyzed theoretically,and an optimal duty cycle modulated model predictive control method is proposed.The cost function is defined by sum of squares of difference between predictive voltage vector and synthetic voltage vector.The duty cycle can be calculated by solving the cost function.In order to compare with the conventional finite control set model predictive control method and modulated model predictive control method at high sampling frequency,these two predictive methods are improved to enable them to operate at high sample frequency.Thirdly,in order to enhance fault tolerant ability of PMSM drive system.An eight-switch three-phase inverter topology is introduced,and a fault tolerant modulated model predictive control method based on this reconstructed topology is derived,which enhances the fault tolerant ability of PMSM driver system.At the same time,a comparative study is made between the conventional finite control set model predictive control method and the proposed method on eight-switch three-phase inverter topology.Simulation and experimental results validate the effectiveness of the proposed method.Finally,in order to enhance the robustness of PMSM driver system,the disturbances of PMSM driver system are analyzed theoretically,and a modulated model predictive sliding mode composite control method is proposed.Modulated model predictive control method is used for the inner loop and the speed loop is a sliding mode control method which combines improved sliding mode reaching law and an disturbance torque observer.The load torque disturbance observer is used to compensate the influence of external disturbance,and the stability of speed loop is proved by using Lyapunov theory.The contradiction between chattering and reaching velocity in conventional sliding mode control is solved and robustness of PMSM drive system is improved effectively.更多还原