【作者】 刘剑；

【导师】 杨贵杰；

【作者基本信息】 哈尔滨工业大学 ， 电机与电器， 2014， 博士

【摘要】 微电子技术和电力电子技术的飞速发展，为电机控制系统摆脱传统的三相拓扑限制奠定了基础，多相发电机与多相变流器结合，为实现大功率或者有更高可靠性要求的发电场合提供了一种新思路。双Y相移30°的六相永磁同步发电机具有低压大功率、容错性能好、控制灵活等优点，可广泛应用于新能源发电、全电推进的舰船发电机、多电飞机、电动车等领域。目前针对多相电机的研究中，对脉宽调制数字化实现、母线串联问题、容错控制中三次谐波问题及传统PI调制的鲁棒性不佳等问题还有待深入研究。论文主要针对六相永磁同步发电机(Six Phase Permanent Magnet Synchrounous Generator, Six Phase PMSG)的基本理论、多维空间脉宽调制方法、预测控制、容错控制中的三次谐波抑制等方面进行了研究，得到的结论和总结出的方法对多相发电机的应用具有理论指导意义和工程实践价值。论文基于绕组函数法分析了绕组磁动势的谐波机理，并对六相PMSG谐波磁动势的分布规律进行了分析，明确了六相PMSG与原动机组成的动力模型中能量传递关系。在六相PMSG相变量模型的基础上，通过正交坐标变换，建立了六相PMSG的空间解耦的数学模型，为后文的各种控制策略的提出打下基础。利用有限元法对六相PMSG的气隙磁密和反电动势进行了谐波分析，对各相绕组的自感和互感进行了计算，指出可以通过改变绕组因数来进行特定次谐波注入和消除，六相PMSG的设计应充分考虑各相绕组之间的互感关系。论文对部分解耦和完全解耦的两种矢量控制技术进行了深入的研究。首先对六相PMSG在两套三相对称绕组中性点隔离的情况下，采用部分解耦的双d-q空间矢量控制时，应用前馈控制消除交叉耦合电感带来的影响。通过对各个扇区的分析，得到导通时间与参考电压之间的系数变化规律。其次，针对最大四矢量法的调制波中心不对称的问题，提出了中心化处理后的最大四矢量PWM策略，对中心化处理后增加的基本矢量对开关导通时间系数的影响进行了分析，继而对连续型和离散型两种最大四矢量PWM方式的谐波机理进行了分析，并进行了仿真和实验验证。针对六相PMSG两套三相绕组经整流后母线串联时存在母线中点电位漂移的现象，通过在谐波子空间注入电流，解决了母线电压中点电位漂移问题。针对六相PMSG采用PI控制策略易受参数影响的问题，论文对预测电流控制和模型预测控制进行了深入细致的研究。通过建立六相PMSG的离散化预测模型，对两步法实现无差拍预测电流控制的过程进行推导，并提出将反馈电流的低频和高频成分分离，修正反馈环节，解决了传统预测电流控制中参考电流与输出电流存在稳态误差的问题。提出了一种基于状态空间变量的六相PMSG模型预测控制方法，建立了六相PMSG基于状态空间模型的预测标准型，同时对六相PMSG模型预测控制中目标函数和控制律参数的设计进行了分析。针对上述两种预测控制方法，实验证明两种控制方法具有快速响应、鲁棒性好的优点。最后，论文针对六相PMSG一相开路时三次谐波电感和磁链的影响进行了深入的研究，建立了一相绕组开路的六相PMSG的空间解耦的数学模型，并针对六相PMSG经一次同步旋转坐标变换后的d-q子空间电压不解耦的情况，提出了对d-q子空间电压完全解耦的二次旋转坐标变换。依据定子磁势不变原则，按照定子铜耗最小和定子电流幅值最小的优化方法，推导了一相开路后的六相PMSG的最优电流解。为消除三次谐波的影响，提出一种可以进行离线计算、工程实现简单的三次谐波闭环补偿控制策略，并对补偿量的大小进行了推导。更多还原

【Abstract】 With the rapid development of micro-electronics and power electronicstechniques, the machine control systems have shaken off the traditional three phaseshackles. The multiphase generator combined with multiphase converter can meetthe requirements of high power and high reliability application. Six phase permanentmagnet synchronous generator (Six Phase PMSG) with dual Y connected and30degree phase shift has several advantages such as low voltage high power output,good performance in fault tolerant, flexible control techniques etc. It is quitesuitable for clean energy such as wind power and tidal energy generation, electricalship propulsion, more electric aircraft, electrical vehicle. At present, there havemany problems in multiphase machine control, such as pulse width modulation(PWM) digital implementation and DC bus series, the third harmonic interference infault tolerant control, poor performance in traditional PI control. This dissertationmainly focuses on the fundamental theory of six phase PMSG, multi-dimensionPWM control method, predictive control, third harmonic effects surpression in faulttolerrant control etc. The conclusions and summarized methods have directivesignificance and practical value in multiphase machine application.Based on the winding function，the machnism of magnetic-motive force (MMF)was analyzed which caused by winding space harmonics interaction with currentstime harmonics. The distribution law of six phase PMSG MMF was analyzed, andthis is the theoretical basis of following chapters. The two mass mechanical dynamicmodel was established which consists with six phase PMSG and prime mover. Byapplying orthogonal frame transformation, the phase variable models of six phasePMSG were transformed into space decoupling model, and they are the basis offollowing control strategies. The harmonics of air-gap flux density and back EMFwere analyzed by finite element analysis (FEA), at mean time, the inductances of sixphase PMSG were figured out by FEA also. By above calculation, the fixedharmonic can be eliminated by changing the winding coefficient was figured out.The design of six phase PMSG should be considered of mutual inductances ofinductance matrix.The incomplete and complete decoupling vector control methods were researcheddeeply. Firstly, the incomplete decoupling method was adopted to the two setwingdings with isolated neutral point topology, an improved control strategy withfeedforward control was proposed to eliminate the cross coupling effects. By theanalysis of each sector, the fixed coefficient variation law was deduced which the active time of the maximum four vectors (MFV) and stationary frame referencevoltage. It is difficult to implement the MFV because the pulse waves of MFV werenot center symmetrical. A improved continuous and a discrete MFV pulse widthmodulation (PWM) methods were proposed with centralized pulse waves, aftercentralized, the newly emerged basic vectors changed the law of active time andstationary frame reference voltage, and harmonic mechanism of MFV modulationwere analyzed, simulation and experiments validates the effectiveness of proposedstrategy. The two set windings with independent rectifier of Six Phase PMSG canseries the DC terminals together which increased the DC-bus voltage dramatically.However, the mid-voltage of the series two DC terminals drift frequently, a novelcontrol strategy was proposed to suppress the drift of DC-bus mid-voltage byinjecting the current in harmonic subspace.For the traditional PI control strategies of six phase PMSG were affected bymachine parameters frequently, the robust predictive current control (PCC) andmodel predictive control (MPC) were deeply researched. An improved deadbeatPCC control strategy was proposed, the discrete model of six phase PMSG wasestablished, and the process of realizing the deadbeat PCC in two steps was deducedclearly. By separating the high frequency components from currents and revising thefeedback part, an improved deadbeat PCC strategy was proposed to eliminate thesteady state error of reference and feedback currents in traditional method. A MPCstrategy for six phase PMSG was proposed based on state space variables. Thestandard form of MPC for six phase PMSG was established, and the cost functionand the parameters of contol law were studied in depth. The experiments validatethe two predictive algorithm merits, such as fast response and good robustness inparameter changing.Lastly, the fault tolerant control strategy in one phase opening mode wasresearched deeply which considering the third harmonic inductance and flux, thespace decoupling model of six phase PMSG were established, for the couplingrelationship of d-q voltage after synchronous frame transformation, to eliminate thethis coupling relationship, a second rotational transformation for d-q voltage wasproposed. According to MMF balance principle, and under the constraint of statorcopper loss minimum (SCLM) and stator current magnitude minimum (SCMM), theoptimized currents solutions for both constrains were figured out. To surppress thethird harmonic effects of flux and inductance in one phase open mode, acompensation control strategy was proposed which considering the third harmonicinductance and flux, it can be calculated offline, and simply implemented inengineering application, The compensation quantity for the closed loop control was deduced.更多还原