六相永磁同步发电机控制技术研究

发布时间：2018-10-16 16:37

【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。
[Abstract]:With the rapid development of micro-electronics technology and power electronics technology, it lays a foundation for the motor control system to get rid of the traditional three-phase topology limit, and the multi-phase generator is combined with the multi-phase converter. the six-phase permanent magnet synchronous generator with a double Y phase shift of 30 DEG has the advantages of low voltage, high power, good fault tolerance, flexible control and the like, and can be widely applied to the fields of new energy power generation, fully electric propulsion ship generators, multi-electric aircraft, electric vehicles and the like. At present, in the research of multi-phase motor, the problems such as digital implementation of pulse width modulation, series problem of bus bar, three harmonic problems in fault tolerance control and robustness of traditional PI modulation are still to be studied deeply. The paper mainly focuses on the basic theory of six-phase permanent magnet synchronous generator (Six Phase PMSG), multi-dimensional space pulse width modulation method, predictive control, third harmonic suppression in fault tolerant control, etc. The results obtained and summarized methods have theoretical significance and practical value for the application of multi-phase generator. Based on the winding function method, the harmonic mechanism of the magnetic dynamic potential of the winding is analyzed, and the distribution law of the six-phase PMSG harmonic magnetic dynamic potential is analyzed, and the energy transfer in the power model consisting of six-phase PMSG and prime mover is clarified. On the basis of the six-phase PMSG-phase variable model, a mathematical model of spatial decoupling of six-phase PMSG is established by orthogonal coordinate transformation. On the basis of the harmonic analysis of the air gap magnetic density and back electromotive force of six-phase PMSG by finite element method, the inductance and mutual inductance of each phase winding are calculated, and it is pointed out that the specific subharmonic injection can be carried out by changing the winding factor. The design of six-phase PMSG shall take full account of mutual inductance between each phase winding. In this paper, two vector control techniques for partial decoupling and complete decoupling are discussed. In this paper, a partially decoupled dual d-q space vector control is used to eliminate cross-coupling inductance when the two sets of three relative symmetric winding neutral points are isolated. by analyzing each sector, a system between the on time and the reference voltage is obtained Secondly, aiming at the asymmetry of the modulation wave center of the maximum four-vector method, the maximum four-vector PWM strategy after the central processing is put forward, and the influence of the basic vector added after the central processing on the switching time coefficient is proposed. The harmonic mechanism of two maximum four-vector PWM modes is analyzed, and the simulation is carried out. and solves the problem of point potential drift in the bus when the two sets of three-phase windings of the six-phase PMSG are connected in series, For the six-phase PMSG, the PI control strategy is easy to be influenced by parameters, and the predictive current control and the model predictive control are carried out in this paper. Based on the discrete prediction model of six-phase PMSG, the process of non-beat prediction current control is deduced by two-step method, and the low-frequency and high-frequency components of the feedback current are put forward. and the reference current and the output current in the traditional predictive current control are solved. In this paper, a six-phase PMSG model predictive control method based on state space variable is proposed in this paper. A six-phase PMSG model based on state space model is established, and the objective function and control law parameters in six-phase PMSG model predictive control are also proposed. According to the two kinds of prediction control methods, the experiment proves that the two control methods have fast response. Finally, the paper studies the influence of three harmonic inductance and magnetic chain in the open circuit of six-phase PMSG, and establishes a six-phase PMS with open phase winding. A mathematical model of spatial decoupling of G is proposed, and the d-q sub-space voltage is not coupled with the six-phase PMSG, and the d-q sub-space voltage is completely solved. According to the principle of stator magnetic potential, this paper deduces the six-phase open circuit according to the stator's minimum copper consumption and the minimum stator current amplitude. In order to eliminate the influence of three harmonics, a three-order harmonic closed-loop compensation control strategy is proposed, which can be taken off-line, and the project implements a simple three-harmonic closed loop compensation control strategy.
【学位授予单位】：哈尔滨工业大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：TM31

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