多相无刷直流电机变饱和柔性变结构控制器设计

Design of Variable Saturation Soft Variable Structure Controller for Multiphase Brushless DC Motors

无刷直流电机因其高效率、长寿命、低噪声及其良好的机械特性等优点,在航空、军事、汽车、办公自动化等行业得到了广泛的应用。考虑到多相永磁无刷电机转子磁路结构及气隙磁密度波形对电机运行性能和控制策略的影响,需要建立精准的电机数学一般模型。而含有积分环节的PID控制使得电机控制系统响应缓慢,加之功率管换向过程中电感的作用,相电压波形与理想方波有较大差距,导致转矩脉动大,转速响应缓慢。通过改变柔性变结构的控制策略,并结合稳定的线性系统,以三相电机为研究对象,提出了多相无刷直流电机变饱和柔性变结构的控制器设计方法。仿真实验结果表明,采用变饱和柔性变结构控制较传统PID控制具有更好的控制性能,转速响应快,转矩脉动小。

The Brushless DC motor （BLDC motor） with the advantages of high efficiency, long life, low noise and good mechanical properties, has been widely used in aviation, military, automotive, office automation and other industries. Considering the effect of ro- tor structure and the air-gap magnet field on operating performance and control strategy, an accurate mathematic model of multi-phase BLDC motor should be derived. That the integrator of PID slows the motor system response and the distortion of phase-voltage waveform is produce by the influence of inductance in reversing process. In order to improve the control system performance, a controller of multi- phase BLDC motor based on variable saturation soft variable structure control is presented, by improving the control strategy of soft vari- able structure with linear system. Results of simulation experiments show that variable saturation soft variable structure control compared with PID control achieves better performance, fast response and small torque ripple.