基于定子磁链控制的IPMSM驱动系统研究

发布时间：2018-01-01 01:30

本文关键词：基于定子磁链控制的IPMSM驱动系统研究　出处：《浙江大学》2017年博士论文　论文类型：学位论文

【摘要】：永磁同步电机由于具有高功率密度、高功率因数、结构简单、体积小、可靠性高、便于维护等优点,被广泛应用在风力发电、新能源汽车、数控机床以及航空航天等领域。永磁电机作为相关应用领域的执行元件,其驱动系统的好坏,直接影响着整套设备的整体性能。因此,本文选择永磁同步电机驱动系统作为研究的重点。鉴于在永磁同步电机中凸极机比隐极机具有更高的转矩电流比、更宽的调速范围和更强的弱磁控制能力,且现有文献对隐极式永磁同步电机控制策略的研究也比较详细,而凸极机由于其dq轴电感值不相等,导致有关控制策略的开发难度相对比较大,因此本文以凸极式永磁同步电机(Interior Permanent Magnet Synchronous Motor,IPMSM)为主要研究对象,尝试利用新提出的定子磁链控制方案来获得较高的转矩响应速度和较低的转矩脉动输出。在定子磁链控制方案中,由于直接使用空间电压矢量调制算法(Space Vector Pulse Width Modulation,SVPWM)来合成参考电压矢量,使得驱动系统附带很高的共模电压输出。为此,本文通过使用修正PWM调制算法来减小驱动系统输出的共模电压,避免电机转轴轴承的过早损坏,进而提高IPMSM的可靠性。另外,鉴于IPMSM驱动系统中功率开关管是一个容易发生故障的薄弱环节,为使IPMSM驱动系统具有一定的容错运行能力,针对逆变器的单相桥臂故障,本文选择三相四开关逆变器作为驱动器故障后的容错运行拓扑,并将定子磁链控制引入到IPMSM驱动系统的容错运行控制当中。首先,推导了基于凸极式永磁同步电机的定子磁链关于时间的微分方程,分别建立了凸极机在静止坐标系下和旋转坐标下以定子磁链为状态变量的状态空间模型。提出了一种基于定子磁链控制的直接转矩控制方案,并分别在旋转坐标系下和静止坐标系下实施。在该方案中,首先分析了定转子磁链矢量之间的位置关系,并将系统的速度外环输出作为转矩角的期望值,进而计算出下一时刻定子磁链矢量的期望值;其次,构建无差拍全阶状态观测器,实现对定子磁链的闭环观测;通过设计状态反馈增益矩阵将系统的闭环极点放置在z平面的正实轴上,并预留一个参数来改变闭环系统的极点位置,调节系统的性能;最后,根据系统的定子磁链误差矢量和所选择的状态反馈增益矩阵来计算参考电压矢量,并将其送入SVPWM模块中。该方案与传统的PI+SVMDTC控制方案相比,移去了转矩环,只通过定子磁链环来控制系统的转矩输出,因而具有更快的转矩响应速度;同时直接以电机内部的定子磁链为控制目标,系统输出的谐波含量更低。实验结果验证了所提控制方案的有效性和优越性。其次,为避免定子磁链控制方案中因采用SVPWM调制方式所产生的共模电压对电机转轴轴承造成的电腐蚀,本文利用AZPSWM1调制算法和NSPWM调制算法来降低驱动器输出的共模电压幅值。鉴于在逆变器正常运行过程中死区时间是必不可少的,本文分别分析了死区条件下,采用AZSPWM1和NSPWM调制算法的逆变器的共模电压输出情况,分析了共模电压抑制算法失效时所需满足的负载功率因数条件和参考电压矢量所处的扇区位置。随后,本文通过限制有关电压矢量的最小作用时间来消除驱动器输出的共模电压尖峰,并分析了此最小作用时间对AZSPWM1和NSPWM适用调制范围的影响。最后,将修正后的AZSPWM1和NSPWM相结合组成混合调制模式,实现了在全功率因数条件下宽调制范围内对共模电压的有效抑制;并将此混合调制算法应用在定子磁链控制系统中。实验结果验证了本文所提出的共模电压抑制算法的有效性。最后,为使驱动器具有一定的容错运行能力,针对驱动器的单相桥臂故障,本文选择三相四开关逆变器作为其故障后的容错运行拓扑。首先,分别介绍了针对不同故障相的三相四开关逆变器的基本特点,设计了相应的无扇区SVPWM调制算法。其次,针对逆变器A相故障,分析了直流母线中性点电压基波分量与定子电流β轴分量之间的关系,基于此关系设计了一个简单算法来替代二阶低通滤波器从直流母线中性点电压中提取直流偏置,并通过PI控制器构成闭环回路实现对直流母线中性点电压中直流偏置的有效抑制。随后,分别针对B相故障和C相故障,修正了上述中性点电压控制方案。再次,针对三相四开关逆变器低频段线性调制范围比较小的问题,本文在分析了逆变器最大线性调制度与负载功率因数之间的关系后,提出了一种在不改变直流母线现有条件的前提下增大逆变器低频段线性调制范围的控制方案,并通过实验验证了该方案的有效性。最后,将定子磁链控制方案引入到基于三相四开关逆变器的IPMSM驱动系统中,并进行了实验验证。
[Abstract]:Permanent magnet synchronous motor has high power density, high power factor, simple structure, small volume, high reliability, convenient maintenance and other advantages, is widely used in wind power, new energy vehicles, CNC machine tools and aerospace fields. Permanent magnet motor related applications as actuators, the drive system is good or bad, directly affect the overall performance of the whole equipment. Therefore, the permanent magnet synchronous motor drive system as the focus of the study. In view of the permanent magnet synchronous motor of convex pole machine than salient pole machine with torque current higher than that in a wide speed range and stronger weak magnetic control ability, and the research of synchronous motor control strategy the existing literature on the non salient pole permanent magnet is detailed, and the salient pole machine because of its DQ axis inductance is not equal to the relevant control strategy, development difficulty is relatively large, so this paper takes the salient permanent magnet with Step motor (Interior Permanent Magnet Synchronous Motor, IPMSM) as the main research object, try to obtain a higher torque response speed and low torque ripple of output by using the stator flux control scheme is proposed. The stator flux control scheme, due to the direct use of space vector modulation algorithm (Space Vector Pulse Width Modulation, SVPWM) to synthesize the reference voltage vector, the drive system with high common mode voltage output. Therefore, this paper through the use of modified PWM algorithm to reduce common mode voltage output of the drive system, avoid the damage to the motor shaft bearing, thus improving the reliability of IPMSM. In addition, in view of the IPMSM in the drive system of power switch is an easy failure of the weak links, in order to make the IPMSM drive system has high reliability, for the single-phase bridge arm fault inverter, this paper Select the three-phase four switch inverter topology as fault tolerant operation drive failure after, and the stator flux control into IPMSM control drive system of the fault tolerant operation. First, differential equations of the stator flux of salient pole permanent magnet synchronous motor on time is deduced based on, we established the salient pole machine in the stationary coordinate system and coordinate with stator flux as state space model of the state variables. This paper presents a direct torque control scheme based on stator flux control, and the implementation in the rotating coordinates and stationary coordinates. In this scheme, firstly analyzes the relationship between the position of the rotor flux vector, and the speed of the system the outer loop output torque angle as the expected value, and then calculate the next time the stator flux vector expected value; secondly, construct the deadbeat full order state observer, the stator flux Close observation; through the design of state feedback gain matrix of the closed-loop poles are placed in the z plane is on the real axis, and a pole position of reserve parameters to change the closed-loop system performance regulation system; finally, according to the stator flux error vector system and the selection of the state feedback gain matrix to calculate the reference voltage vector, and sent to the SVPWM module in PI+SVMDTC. Compared with the traditional control scheme, removed the torque loop, the output torque only through the stator flux loop control system, which has faster response speed and torque; direct to stator flux inside the motor as the control target, lower harmonic content of output experiments. The results verify the validity and superiority of the proposed control scheme. Secondly, in order to avoid the stator flux control scheme by using SVPWM modulation generated by the common mode voltage of motor Electric corrosion caused by the shaft bearing, this paper uses AZPSWM1 modulation algorithm and NSPWM algorithm to reduce the common mode voltage amplitude driver output. In view of the dead time of inverter in the normal operation of the process is essential, this paper analyzes the dead time conditions, the output common mode voltage inverter AZSPWM1 and NSPWM modulation algorithm, analyzes the common mode voltage inhibition of sector position, meet the needs of the algorithm failure load power factor condition and the reference voltage vector. Then, through the limitation of the minimum working time of voltage vector to eliminate the common mode voltage spike driver output, and analyzed the influence of the minimum duration on the applicable range of AZSPWM1 modulation and NSPWM. Finally, the correction after the AZSPWM1 and NSPWM combination of hybrid modulation mode, the total power factor under the condition of wide range of modulation Effective suppression of common mode voltage; and the hybrid modulation algorithm is applied to the stator flux control system. The experimental results verify the effectiveness of the proposed common mode voltage suppression algorithm. Finally, the driver has high reliability, for the single-phase bridge arm failure drive, this paper chose the three-phase four switch inverter for fault tolerance run the topology failure. Firstly, the paper introduces the basic characteristics of different fault phase of the three-phase four switch inverter, designed without sector SVPWM modulation algorithm accordingly. Secondly, according to the A phase inverter fault, analyzes the relationship between the DC bus voltage of the neutral point and fundamental component of stator current beta axis component, based on this the relationship between the design of a simple algorithm to replace the two order low-pass filter to extract the DC bias from the DC bus voltage of the neutral point, and through the PI controller to form a closed loop Loop to achieve effective suppression of the DC bias voltage of the neutral point of the DC bus. Then, according to phase B fault and C fault, fixed above the neutral point voltage control scheme. Thirdly, aiming at the three-phase four switch inverter frequency linear modulation range is relatively small, this paper analyzes the relationship between the maximum linear modulation inverter the system and the load power factor, put forward a kind of without changing the existing conditions of DC bus under the premise of increasing frequency inverter linear modulation range control scheme, and the effectiveness of the scheme is verified by experiments. Finally, the stator flux control scheme is introduced based on the three-phase four switch inverter IPMSM drive system. And experiments were carried out.

【学位授予单位】：浙江大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：TM341

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