轨道交通无变压器牵引传动系统中双定子感应电机控制策略研究

发布时间：2018-04-16 14:28

本文选题：双定子感应电机 + 矢量空间解耦变换　；参考：《北京交通大学》2017年博士论文

【摘要】：多相电机牵引系统的转矩脉动频率高、脉动幅值小,可靠性高、容错能力强,并且可以利用现有低压功率开关器件实现大功率等级,特别适合于舰船电力推进系统、轨道交通牵引系统等低电压、大功率、高可靠性的领域。本文针对轨道交通无变压器牵引传动系统中双定子感应电机在控制和调制方面的关键问题进行了研究,主要包括以下内容:利用矢量空间解耦变换理论,建立了双定子感应电机的解耦数学模型,并在此基础上,详细研究了双定子感应电机的电流控制策略,包括基波平面电流控制策略和谐波平面电流抑制策略。在基波平面,采用复矢量分析法建立电机的复矢量数学模型,利用零极点对消原理设计了复矢量电流调节器,能够实现电机的解耦控制;在谐波平面,推导了由逆变器或者电机的不对称性引起的谐波电流的物理意义,并对五种不对称电流抑制方法进行了对比分析。针对两电平六相逆变器供电的双定子感应电机,提出了一种改进型24扇区SVPWM调制方法,该方法具有良好的电压输出性能,可以有效减少谐波平面的谐波电压分量。为了简化SVPWM方法的计算过程和实现过程,通过对改进型24扇区SVPWM方法与载波PWM方法的一致性关系进行推导和证明,提出了改进型24扇区SVPWM方法的等效载波PWM实现方法,可以大大简化算法的复杂程度,节省计算资源,更易于DSP等计算芯片的数字化实现。为了满足低开关频率条件下双定子感应电机的调制要求,提出了两种同步调制策略:基于传统24扇区SVPWM方法的同步调制策略和基于改进24扇区SVPWM方法的同步调制策略,并对所有方法的输出电压性能进行了比较研究。除此之外,根据逆变器最高开关频率的限制,提出了双定子感应电机在全速度范围内的多模式SVPWM调制策略和不同调制模式之间的切换策略。结合多模式SVPWM调制策略的特点,提出了双定子感应电机在全速度范围内的矢量控制策略,可以满足大功率牵引电机在低开关频率限制条件下的高性能控制要求。此外,为了解决由于各种原因引起的转子磁场定向不准确问题,分别采用了适用于非方波工况的基于q轴观测磁链的磁场定向校正策略和适用于方波工况的基于q轴电流偏差的磁场定向校正策略。最后,设计并搭建了轨道交通无变压器牵引传动系统的四级实验平台。针对级联型H桥整流器有源前端的控制策略和各级直流母线电压的平衡控制策略进行了研究;通过分析级联型H桥整流器的稳定工作域,提出了两台双定子感应电机的协调控制策略,并利用实验平台进行了相关的实验验证。
[Abstract]:The traction system of multiphase motor has high torque ripple frequency, small pulsation amplitude, high reliability, strong fault-tolerant ability, and can use the existing low-voltage power switch devices to realize the high power grade, which is especially suitable for naval electric propulsion system.Railway traction system and other low-voltage, high-power, high-reliability areas.In this paper, the key problems in control and modulation of dual stator induction motor in traction drive system without transformer in rail transit are studied. The main contents are as follows: using vector space decoupling transformation theory,The decoupling mathematical model of double stator induction motor is established, and the current control strategy of double stator induction motor is studied in detail, including fundamental current control strategy and harmonic plane current suppression strategy.In the fundamental plane, the complex vector mathematical model of the motor is established by using complex vector analysis method, and the complex vector current regulator is designed by using the principle of zero pole cancellation, which can realize the decoupling control of the motor.The physical meaning of harmonic current caused by the asymmetry of inverter or motor is deduced, and five asymmetric current suppression methods are compared and analyzed.An improved 24-sector SVPWM modulation method is proposed for two-level six-phase inverter fed double-stator induction motor. This method has good voltage output performance and can effectively reduce harmonic voltage components in harmonic plane.In order to simplify the calculation and implementation of the SVPWM method, the consistency relationship between the improved 24 sector SVPWM method and the carrier PWM method is deduced and proved, and the equivalent carrier PWM implementation method of the improved 24 sector SVPWM method is proposed.It can greatly simplify the complexity of the algorithm, save computing resources, and is easier to realize digitally the DSP and other computing chips.In order to meet the modulation requirements of double-stator induction motor at low switching frequency, two synchronous modulation strategies are proposed: one based on the traditional 24 sector SVPWM method and the other based on the improved 24 sector SVPWM method.The output voltage performance of all methods is compared and studied.In addition, according to the limitation of the maximum switching frequency of the inverter, the multi-mode SVPWM modulation strategy and the switching strategy between different modulation modes are proposed for the double-stator induction motor in the full speed range.Combined with the characteristics of multi-mode SVPWM modulation strategy, the vector control strategy of double-stator induction motor in full speed range is proposed, which can meet the high performance control requirements of high-power traction motor under the condition of low switching frequency limit.In addition, in order to solve the problem of rotor magnetic field orientation inaccuracy caused by various reasons,Magnetic field orientation correction strategies based on Q axis observation flux linkage and Q axis current deviation are adopted respectively for non square wave mode and square wave mode respectively.Finally, the four-level experimental platform of traction transmission system without transformer in rail transit is designed and built.The control strategy of active front end of cascaded H-bridge rectifier and the balancing control strategy of DC bus voltage are studied, and the stable working area of cascaded H-bridge rectifier is analyzed.A coordinated control strategy for two double stator induction motors is proposed, and the experimental results are verified by using the experimental platform.
【学位授予单位】：北京交通大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：U264.91

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