谐波注入的多相高功率密度感应电机系统控制及容错运行研究

The multi-phase motor system is utilized widely for the remarkable characteristics, such as low torque oscillations, high reliability, convenient to realize high power by low-voltage power switch, and et al. Especially, in high power applications, such as electric ship propulsion, aircraft drive, locomotive traction, and et al, the multi-phase system regarded as one of the most effective techniques receives a lot of favors. The key techniques to increase the power density and reliability of multi-phase system, have became hot-pot investigated by researchers in many countries. This project chooses five-phase concentrated full-pitch windings induction motor control system as the research object. The problem of air-gap flux density optimization will be discussed with the precondition of maximum power density of this system. On the basis above, the vector control method with third harmonic current injected will be proposed, by which the output power density of the motor will be increased. Simulations and experiments will be implanted on the designed five-phase induction motor using the proposed third harmonic current injected method, and the variation law of system performance parameter in different work conditions will be analyzed, such as DC-bus voltage utilization ratio, power factor, efficiency, output voltage and current, and et al to verify the feasibility of method above. Finally, the tolerant operation for five-phase induction motor under open fault will be researched. By comparing the back MMF before and after under open phase operation, the tolerant control method with minimal torque oscillations will be proposed, and the reliability of this system will get improved. The research achievements in this project will make up the existing method’s insufficiency, and supply important theoretical and technological basis for ship electric propulsion.

多相电机系统因具有低转矩脉动、高可靠性、易于通过低压功率器件实现大功率等优点，而得到了广泛的应用。特别是在船舶、航天、机车电力推进等大功率应用环境中，多相电机系统作为最有效的技术途径之一，广受青睐。如何提高多相电机的功率密度和多相电机系统的可靠性等关键性技术问题，已成为各国学者竞相研究的热点。本项目以五相感应电机为研究对象，在考虑系统功率密度最大的前提下，分析气隙磁场优化问题。在此基础上，提出3次谐波电流注入的矢量控制方法，从而大幅提高电机功率密度；采用提出的方法对设计的电机进行仿真与实验研究，分析不同工况下，系统母线电压利用率、功率因数、效率、电压电流等指标的变化规律，验证上述方法的可行性；最后，对电机缺相运行进行研究。通过对比电机缺相前后磁势分析结果，提出最小转矩脉动容错控制方法，提高系统运行的可靠性。本项目中的研究成果将弥补现有方法不足，为船舶电力推进提供重要的理论和技术基础。

本项目以五相集中整距绕组感应电机为研究对象，在非正弦供电时对电机磁势谐波分析基础上，建立了考虑3次谐波空间时五相集中整距绕组感应电机的数学模型，研究了3次谐波注入的五相感应电机控制策略及系统缺相容错运行等关键技术问题。.鉴于采用直接转矩控制，存在当电机所带负载较大时无法实现准方波的气隙磁密以及难以实现容错运行等问题，重点研究了3次谐波注入的矢量控制。为此，提出了分别基于异步旋转变换和基于同步旋转变换的气隙磁场间接控制方法。这两种方法从不同的角度进行分析，分别建立了3次谐波直轴、交轴分量与基波之间的非线性关系表达式，均实现了对气隙磁密为准方波的控制。项目中对这两种方法的具体实现过程进行了深入研究，特别是对参考电压实现方式和磁链观测等关键技术问题展开了深入分析。.分析了3次谐波电流注入对系统直流母线利率、功率因数、效率及转矩密度等几个重要指标的影响。采用该控制方法时，须考虑3次谐波空间，而3次谐波空间参数计算误差，会直接影响整个系统的控制性能。为此，分析了转子3次谐波等效参数对电机控制性能的影响。.通过对电机缺相后磁势分析，得到了转矩脉动最小时剩余各相绕组中电流必须满足的条件，为此，提出了磁势视角分析的最小转矩脉动容错控制方法。该方法充分考虑了基波、3次谐波耦合带来的影响，弥补了转矩视角控制方法的缺陷。.搭建了五相H桥变频调速系统仿真实验平台，对项目中提出的分析方法和控制理论进行了实验验证。