【作者】 王东；

【导师】 刘自程；

【作者基本信息】 华中科技大学 ， 新能源科学与工程， 2024， 硕士

【摘要】 同步磁阻电机采用凸极转子,不含永磁体,通过最小磁阻原理产生电磁转矩。因此同步磁阻电机具有低成本、控制简单和高温耐受性等优势,从而在多个领域展现了广阔的应用前景。然而同步磁阻电机也存在功率因数低,转矩脉动高等缺陷。多相电机具备多自由度、低转矩脉动和高容错能力等特点。为了提高同步磁阻电机驱动控制中的功率因数等性能,本文其进行多相拓展并引入带悬浮电容的逆变拓扑,从数学模型、驱动拓扑、无功功率补偿、非理想因素等角度,进行了相关的驱动控制研究。首先,为了研究同步磁阻电机电压、电流、磁通和转矩等参数之间的关系,本文在自然坐标系下建立了数学模型,分析了高度的耦合性。为了简化控制过程,本文采用针对多相半对称电机的广义Park变换矩阵,推导出了双Y移30°半对称同步磁阻电机的数学模型,进而推导了同步磁阻电机矢量控制环节中不同的电流分配方式所采用的电流角,并对矢量控制系统进行了设计和仿真验证。针对六相同步磁阻电机驱动系统,本文创新性地引入了带悬浮电容的开绕组拓扑。从开绕组拓扑的结构出发,说明了带悬浮电容的开绕组拓扑中不存在零序电流的原因。从电压电流矢量关系出发,说明了该拓扑如何实现对主逆变器进行无功功率补偿。在此基础上,设计了辅逆变器侧的电容电压控制环、单位功率因数控制环。最后考虑极端工况下的电压波动,对该拓扑中的电容容值进行了选型。通过仿真说明了带悬浮电容的六相同步磁阻电机驱动控制系统实现单位功率因数的可行性。针对六相同步磁电机驱动系统中的基波和谐波平面的电流成分进行了分析,据此对各个平面出现的最低次谐波进行了相应频率的旋转变换控制,提升谐波抑制的精准度并减少谐波损耗。同时,本文分析了在各相绕组出现电流不均衡时基波和谐波平面电流分量特征,通过对这些分量中的基波成分进行抑制,实现了电流幅值的均衡控制,从而提升了系统的稳定性。更多还原

【Abstract】 The synchronous reluctance motor,employing a salient pole rotor without permanent magnets,generates electromagnetic torque based on the principle of minimum reluctance.Consequently,it offers significant advantages over other motors,including lower manufacturing costs,simple control,and high temperature resistance,thus demonstrating considerable application potential.However,synchronous reluctance motors also exhibit some drawbacks,such as low power factor and high torque ripple.Multiphase motors are characterized by multiple degrees of freedom,low torque ripple,and high fault tolerance.To enhance the performance metrics such as power factor in the drive control of synchronous reluctance motors,this paper extends the configuration to multiphase and introduces an inverter topology with floating capacitors.This study covers various aspects including mathematical modeling,drive topology,reactive power compensation,and the influence of non-ideal factors.Initially,to investigate the relationships among voltage,current,flux,and torque parameters in synchronous reluctance motors,a mathematical model was established in the natural coordinate system,analyzing the high degree of coupling.To simplify the control process,this study employs a generalized Park transformation matrix tailored for multiphase semi-symmetric motors.It derives the mathematical model for a dual-Y 30-degree shifted semi-symmetric synchronous reluctance motor.Subsequently,different current distribution methods for vector control loops are deduced,and the vector control system is designed and validated through simulation.In this paper,the topology of open windings with floating capacitors is applied to the drive system of a six-phase synchronous reluctance motor.Starting from the structure of the open winding topology,the absence of zero-sequence currents in this configuration with floating capacitors is explained.Based on the vector relationship between voltage and current,this topology’s ability to provide reactive power compensation to the main inverter is elucidated.Building on this,a control loop for the capacitor voltage on the auxiliary inverter side and a unity power factor control loop were designed.Lastly,considering extreme conditions of voltage fluctuations,the capacitance values within this topology were selected.Simulations demonstrate the feasibility of achieving unity power factor in the drive control system of a six-phase synchronous reluctance motor with floating capacitors.Furthermore,an analysis of the fundamental and harmonic current components in the six-phase synchronous reluctance motor drive system is presented.Based on this,the lowest-order harmonics appearing in each plane were subjected to a rotational transformation control at corresponding frequencies,enhancing the precision of harmonic suppression and reducing harmonic losses.Additionally,this paper examines the characteristics of fundamental and harmonic current components in the phase windings under conditions of current imbalance.By suppressing the fundamental components within these currents,an even control of current amplitudes was achieved,thereby enhancing the stability of the system.更多还原