横向磁通永磁电机(TFPMM)因结构特殊,存在功率因数低、转矩脉动大等问题,需要改进控制算法来降低电机的转矩脉动,改善控制系统性能.在传统的直接转矩控制(DTC)基础上提出空间矢量调制(SVM)的DTC策略,以改善传统控制策略中电流、磁链控制不精确,转矩脉动大的问题.针对TFPMM齿槽转矩比较大的问题,将电机齿槽转矩拟合成电角度的表达式,补偿到转矩观测器输出端,使转矩观测器能观测齿槽转矩分量,起到抑制齿槽转矩脉动的作用.仿真结果验证SVM-DTC比传统DTC的电流波形更平滑,磁链控制更精确.采用齿槽转矩补偿的方法后电机转矩脉动显著减小,验证了补偿控制算法的有效性.改进的控制算法提高了电机控制系统整体性能.
为了缩减电机设计周期,该文针对横向磁通永磁电机提出一种非线性动态等效磁网络模型.该模型引入电机饱和深度系数来反映电机不同饱和程度对导磁材料性能的影响.文中着重分析定转子齿和气隙位置磁通管的划分和相应磁阻的计算.在电机转动过程中,根据定转子的相对位置,把电机的一对极范围划分为8个区域,每个区域内的等效磁阻分布均相同.并且用统一的拓扑表示这8个区域的等效磁网络,从而将动态过程转化为静态拓扑.在求得电机磁链的基础上,对电机的电感、空载反电势进行分析计算.最后通过有限元方法和实验,验证该模型的有效性.
以新型四相横向磁通永磁电机为研究对象,利用MATLAB/Simulink软件平台以及Simpower System工具箱,对闭环控制系统进行了研究.在传统双闭环调速控制基础上,为滞环电流控制环引入零电平,将滞环分为上滞环和下滞环.综合考虑开关频率与电流THD确定合适的滞环环宽,并根据偏差电流值与滞环环宽比较值得到逆变器控制信号.通过仿真得到各种工况下的电机运行数据,说明该控制方法能够对四相横向磁通永磁电机进行有效控制.
Transverse flux permanent magnet motor has the characteristics of high torque density, good fault tolerance, easy control, etc. In this paper, a four-phase transverse flux permanent magnet motor is taken as the control object. Based on the PR regulator, the current loop is designed to control the AC current, achieving excellent current following performance. Meanwhile, the control system algorithm is simple, reducing multiple rotation coordinate transformation compared with traditional permanent magnet synchronous motors vector control system. In this paper, the control system is simulated and verified based on Simulink. The results show that the control system can achieve excellent dynamic performance and stable performance.
提出一种基于转子齿偏移的方法,有效削弱横向磁通永磁电机齿槽转矩。运用傅里叶级数分析了四相横向磁通永磁电机齿槽转矩的表达式,并以此为基础给出了转子齿偏移角度的计算公式。由于该电机结构特殊,单元结构中的两相耦合度高且漏磁系数较大,使得解析方法的计算结果存在误差。为了得到更精确的偏移角度,采用有限元方法对计算所得偏移角度进行修正仿真。此外,还研究了转子齿偏移之后对电机性能的影响,并得出结论:该优化方法能有效削弱齿槽转矩,显著减小电机转矩脉动。同时,结合横向磁通电机的特点,提出了增加齿宽的方法以解决电机优化过程带来的电机出力减小的问题。
As a result of the 3-D magnetic field and complex structure, existing motor design programs are not suitable for the transverse flux permanent magnet motor (TFPMM). Hence, a method combining particle swarm optimization (PSO) algorithm and response surface methodology (RSM) is proposed to optimize a TFPMM. The optimization aims to maximize the no-load electromotive force (EMF) to get higher torque density in the same volume of the motor. First, central composite design method is adopted for experiments on geometrical design variables. Next, the finite-element method is utilized for simulations to determine the coefficients of the second-order analytical model for the RSM. The optimal solution of the model is then obtained by MATLAB PSO toolbox. Finally, we compare the optimized model with a prototype owning the same volume. The results show that with optimization, the no-load back EMF is improved by 10%, so is the output torque, which illustrates the effectiveness of the optimization method.
