【作者】 石松；

【导师】 刘自程；

【作者基本信息】 华中科技大学 ， 电气工程， 2023， 硕士

【摘要】 多相电机系统与传统三相电机系统相比,更适合高可靠性的电力传动场合,然而母线电容体积和开关器件数量会影响多相电机驱动器的高功率密度设计。本文以双三相永磁同步电机驱动系统为对象,针对减小母线电容的体积和减小开关器件数量的拓扑展开研究,具体内容如下:首先,本文建立了双三相永磁同步电机数学模型,发现电机子单元三相绕组存在空间排列不对称,从而导致三相电感值不对称。进一步地,基于脉冲电压注入法,分析了电感不对称对转子初始位置检测结果的影响,并提供了相应的误差消除方法,保证了电机转子初始位置辨识的准确性,为后续研究打下基础。随后,研究了双三相永磁同步电驱动系统母线电容体积优化的调制策略。通过对两个并联三相逆变器的母线电容纹波电流的分析,发现使用载波移相调制技术,可以降低母线电容纹波电流的有效值,进而减小母线电容体积,提高驱动系统的功率密度。此外,在同等工况下,针对三相电机、串联绕组一分二得到的双三相电机、并联绕组一分二得到的双三相电机等三种电机方案,对比了所对应驱动系统的直流母线电容纹波电流大小。理论分析和实验结果表明,减小电容纹波电流的最佳方案为并联绕组一分二方案的双三相电机并结合载波移相调制技术。最后,从减少开关器件数量的角度,提出了四桥臂逆变器驱动双三相永磁同步电机的新型拓扑结构。所提出的四桥臂逆变器拓扑不仅能以与传统六桥臂逆变器拓扑相同的转矩能力驱动双三相永磁同步电机,而且还能避免传统四桥臂逆变器拓扑中的电容中点电压波动问题。此外,针对提出的四桥臂逆变器拓扑提出了两种PWM调制方法,并对两种PWM调制策略的载波比较实现方式及其对应的电流谐波性能进行了对比分析。更多还原

【Abstract】 Compared with traditional three-phase motor systems,multiphase motor systems are more suitable for high-reliability power drive applications,but the volume of the DC-link capacitance and the number of switching devices affect the high power density design of multiphase motor drivers.In this paper,the dual three-phase permanent magnet synchronous motor drive system is used to optimize the DC-link capacitance and reduce the switching device topology,and the specific contents are as follows:Firstly,this paper establishes a mathematical model of a dual-three-phase permanent magnet synchronous motor and finds that the three-phase windings of the motor subunit have an asymmetric spatial arrangement,resulting in an asymmetry of three-phase inductance values.Furthermore,based on the pulse voltage injection method,the influence of inductance asymmetry on the initial position detection results of the rotor is analyzed,and the corresponding error elimination method is provided to ensure the accuracy of the initial position identification of the motor rotor and lay a foundation for subsequent research.Secondly,the modulation strategy for DC-link capacitance volume optimization of dual three-phase permanent magnet synchronous electric drive system was studied.Through the analysis of the DC-link capacitance ripple current of two parallel three-phase inverters,it is found that the effective value of the DC-link capacitance ripple current can be reduced by using carrier phase shift modulation technology,thereby reducing the DC-link capacitance volume and improving the power density of the drive system.In addition,under the same working conditions,the DC-link capacitance ripple current of the corresponding drive system was compared for three motor schemes,such as a three-phase motor,a dualthree-phase motor obtained by series winding in two,and a dual-three-phase motor obtained by parallel winding in two.Theoretical analysis and experimental results show that the best solution to reduce capacitor ripple current is a dual-three-phase motor with parallel winding two-part scheme combined with carrier phase-shift modulation technology.Finally,from the point of view of reducing the number of switching devices,a new topology of the four-leg inverter driving a dual three-phase permanent magnet synchronous motor is proposed.The proposed four-leg inverter topology can not only drive dual threephase permanent magnet synchronous motors with the same torque capability as the traditional six-leg inverter topology,but also avoid the problem of voltage fluctuation at the midpoint of capacitance in the traditional four-leg inverter topology.In addition,two PWM modulation methods are proposed for the proposed four-leg inverter topology,and the carrier comparison implementation of the two PWM modulation strategies and their corresponding current harmonic performance are comparatively analyzed.更多还原