表贴式永磁交流伺服电机永磁体涡流损耗降耗方法

A method for decreasing the eddy current loss in surface- mounted permanent magnet of AC servo motor

针对永磁交流伺服电机中永磁体涡流损耗导致温升,以及表贴式永磁体安装难度大、成本高的问题,提出转子q轴开T型槽的方法。以10极12槽的表贴式永磁伺服电机为研究对象,设计了1台等厚瓦片式永磁体的原型机(200 W,3 000 r/min),通过分析电机额定转矩、永磁体涡流损耗与永磁体极弧系数之间的关系,指出离q轴越近的永磁体,其转矩贡献越小,涡流损耗越大,这为削减q轴附近永磁体厚度和转子q轴开槽提供了依据。在此基础上,对转子开槽的电机进行有限元仿真。结果表明,在转子q轴开T型槽可以削弱电机谐波磁场,从而降低永磁体涡流损耗,且与直槽相比能够拓展开槽空间。对电机结构进行优化设计,在降低永磁体涡流损耗的同时,利用T型槽结构解决了表贴式永磁体的安装问题。

A method of opening T-slots at the q-axis of the rotor was proposed aiming at the eddy current loss in permanent magnet AC servo motor and the difficulty in fixing surface-mounted permanent magnet.Taking 10 poles 12 slots surface-mounted permanent magnet servo motor as the research object,a prototype motor(200W,3000r/min)with constant thickness tiled magnets was designed.By analyzing the relationship between motor rated torque,permanent magnet eddy current loss and polar arc coefficient of permanent magnet,it is pointed out that the closer the magnet is to the q-axis,the smaller the torque contribution and the greater the eddy current loss,which provides an evidence for reducing the thickness of magnets near the q-axis and slotting in the q-axis of the rotor.On this basis,the finite element simulation of the rotor slotted motor is carried out.The results show that opening the T-shaped slot on the q-axis of the rotor can weaken the harmonic magnetic field of the motor,thereby reducing the eddy current loss of the magnet,and can expand the slotting space compared with the straight slot.The T-slot structure is used to solve the fixation problem of the surface-mounted permanent magnet while reducing the eddy current loss of the magnet through the optimized design of the motor structure.