内置式永磁伺服电动机及其系统的研究

【作者】 吴晓红；

【导师】 李光友；

【作者基本信息】 山东大学 ， 电机与电器， 2007， 硕士

【摘要】 正弦波永磁同步电动机(Permanent Magnet Synchronous Motor，简称PMSM)的迅速发展，使以其作为执行机构的交流伺服系统在现代高性能伺服系统中得到了极为广泛的应用。作为伺服电机，必须想方设法的减少电机的纹波转矩和齿槽转矩。而减少纹波转矩的一种方法就是使永磁体产生的励磁磁场在空间尽量按正弦规律分布。本文研究的是内置式PMSM，此种电机不能用优化表面式PMSM的方法来达到使气隙磁密呈正弦分布的目的。本文采用优化转子表面形状的方法来优化内置式PMSM的气隙磁密。表面式PMSM因为L_d=L_q，用于伺服系统时常采用i_d=0控制。如果用内置式PMSM来代替表面式PMSM，且仍旧采用i_d=0控制，就要采取一定的措施，以使L_q接近L_d。在本文中提出一种内置式PMSM样机，该样机的气隙磁密接近梯形分布，所以需对样机进行优化。对样机转子表面形状进行优化的过程中，采用B样条曲线来确定转子表面形状的变量，然后通过Ansys软件提供的参数化设计语言——APDL，对转子的优化设计要素进行设置，在多次优化循环后得出符合条件的比较理想的优化结果——气隙磁密呈正弦分布，且其谐波分量相对样机有明显的减少。优化内置式PMSM表面形状的方法还可以应用在位置传感器的设计中，使位置传感器在一定的限制条件下提供正弦信号。根据给出的样机的技术数据在Rmxprt软件中对电机进行电磁设计，得到样机的稳态参数和性能。设计计算完成后生成二维模型，在Maxwell软件中对模型进行静态和动态分析。优化后的电机不仅凸极率减小了，而且转矩脉动也变小了，说明优化提高了电机的性能。采用i_d=0控制，使用SimPowerSystem中的永磁同步电机模块建立PMSM伺服控制系统仿真模型。利用模型仿真了实际系统的起动、制动和负载。仿真结果与实验结果相符，证明了仿真模型的正确性与实用性。通过MotionComponent软件对三相永磁同步电动机的定位、驱动和跟踪功能，进行了电机空载实验。更多还原

【Abstract】 With the rapid development of sine-wave permanent magnet synchronous motor, ac serve system which implement department is sine-wave PMSM has been used widely in modern high performance serve system. It was necessary for serve motor to reduce its ripple torque and cogging torque. One way which can reduce ripple torque is to make the excitation field produced by permanent magnets distribute following sine rules as far as possible. The interior PMSM is studied in the paper, and this kind of motor can’t excite air-gap flux density with the sinusoidal distribution by optimizing the surface PMSM.Because of L_d =L_q, the surface PMSM often adopt i_d =0 control method when it is used in servo system. Some methods need to be introduced to make L_q approach L_d if surface PMSM was replaced by interior PMSM and the i_d = 0 control method was still adopted. An interior PMSM prototype is proposed in the paper. Because its air-gap flux density distribution is almost trapezoid wave, the interior PMSM needs to be optimized. In the optimization of the shape of prototype’s rotor, the B-spline curve is used to get variables of rotor’s shape. Then, the optimization elements of rotor are set throughAnsys parametric language-APDL. More appropriate and ideal optimization resultcan be gotten after many times optimized repetition. The air-gap flux density is sinusoidal distributed, and its harmonic contents reduce obviously. The optimization method of the interior PMSM rotor’s shape can also be used in the design of position sensor to make the position sensor offer sinusoidal signal under some limited condition. According to the given technical data of prototype, the electromagnetism design of the motor can be done in the Rmxprt software in order to get the steady parameters and performances. After the design and calculation, the two- dimension model can be created. The model is analyzed under static state and dynamic state in Maxwell software. After the optimization, the motor’s salient ratio diminishes and its torque ripple reduces. It accounts for that the optimization improves the motor’s performance.The simulation model of PMSM servo control system can be built by adopting i_d=0 control method and using PMSM module of SimPowerSystem. The composition of each module in the model is analyzed. The model simulates the start-up, braking and loading of the actual system. The results of simulation conform to experiment results, which could prove the correctness and practicability of the model. The no-load experiment of the three-phase PMSM is performed by using the orientation, driving and tracking functions of the MotionComponent software.更多还原