新型非奇异终端滑模观测器的永磁同步电机无传感器控制

A Novel Nonsingular Terminal Sliding Mode Observer for Sensorless Control of Permanent Magnet Synchronous Motor

为了实现对永磁同步电机无位置矢量控制系统所需的转子位置和速度的准确估计,提出一种基于跟踪微分器的新型非奇异快速终端滑模观测器(NFTSMO)。首先,构建积分型非奇异快速终端滑模面,使电流观测误差在有限时间内快速收敛到零,避免了终端滑模存在的奇异问题及传统非奇异终端滑模面中微分状态带来的噪声;然后,结合具有终端吸引子的低抖振切换控制设计滑模控制律,经过跟踪微分器获得平滑的反电动势估算值,减小了传统滑模观测器中低通滤波器引起的相位滞后;最后,基于锁相环原理,从观测的反电动势中调制出转子位置和速度信息。仿真结果表明,采用文中提出的新型滑模观测器可以实现对永磁同步电机转速的准确估计,转速最大估计误差在±1r/min之间,且估计的转子位置无相位滞后,误差小,系统动、静态响应好。与传统滑模观测器相比,该新型滑模观测器具有收敛速度更快、跟踪精度更高、反电动势抖振更小的特点,当系统存在负载扰动及参数摄动时,仍然能够准确地估算出电机转子的位置和速度,具有较强的鲁棒性。

Aiming at the accurate estimation of rotor position and speed of permanent magnet synchronous motor for the sensorless vector control system,a novel nonsingular fast terminal sliding mode observer based on tracking differentiator,named NFTSMO,is proposed.First,a nonsingular fast terminal sliding mode surface in form of integration is constructed,which makes the observation error of currents converge to zero in finite time and avoids the singular problem as well as the noises produced by the conventional nonsingular terminal sliding mode surface.Then,the sliding control law is developed with low chattering switching control combined with terminal attractor.The smooth estimation of the back electromotive-force is obtained through the tracking differentiator,and the phase lag caused by the low-pass filter in traditional sliding mode observer is decreased.Finally,the information of rotor position and speed is modulated from the observed back electromotive-force by the phase-locked loop.The simulation results show that the proposed nonsingular fast terminal sliding mode observer can accurately estimate the rotor position and speed of permanent magnet synchronous motor.The maximum error of speed estimation isbetween ±1r/min,and the estimated rotor position has no phase lag.The system has good dynamic and static performances.Compared with the traditional sliding mode observer,the proposed observer has advantages of faster convergence rate,higher tracking accuracy,lower chattering of back electromotive-force.Besides,the proposed observer has strong robustness in the presence of load disturbances and parameter perturbations.