无轴承永磁同步电机直接转矩控制新型建模方法

A New Modeling Method for Direct Torque Control of Bearingless Permanent Magnet Synchronous Motor

无轴承永磁同步电机采用直接转矩控制策略时,针对电机实际运行过程中由于转矩绕组发热等原因造成其电阻阻值Rs发生变化,转矩绕组磁链位置角θse计算存在偏差,转矩绕组磁场无法实现精确定位等局限性。本文建立了基于转子磁场定向的无轴承永磁同步电机直接转矩控制的数学模型,该数学模型在转子磁场能够精确定位的基础上加上转矩角δ,即能够实现对转矩绕组磁场的精确定位,避免了由于电机自身参数变化造成的计算误差,为进一步提高电机的控制精度提供了理论基础。仿真结果表明本文提出的数学模型具有较高的准确性和一定的可行性。

The direct torque control（ DTC） strategy is being used to control the bearingless permanent magnetic synchronous motor（ BPMSM）. Because of the influence of torque windings＇ resistance Rs,which value is not constant in result from reasons such as the heating of the motor in the process of its running,therefore,there is a certain error of torque winding flux linkage angle θse obtained,and the precise position of the torque winding magnetic field can not be achieved. This paper refered to a mathematical model based on rotor magnetic field orientation of BPMSM direct torque control,aiming at realizing the precise positioning of the torque winding magnetic field on the basis of the accurate positioning of the rotor magnetic filed and torque angle δ,which can avoid the calculation error caused by parameters variation of motor itself and has the vital significance to improve the control precision of the machine. The simulation results showed that the proposed mathematical model based on rotor magnetic field orientation of BPMSM direct torque control was feasible and accurate.