基于双观测器的永磁同步电机无差拍预测电流控制扰动抑制方法

A Dual-Observer-Based Disturbance Suppression Deadbeat Predictive Current Control Method for PMSM Drives

  • 摘要: 无差拍预测电流控制(deadbeat predictive current control,DPCC)因其快速的动态响应和优异的跟踪性能,被广泛应用于永磁同步电机(permanent magnet synchronous motors,PMSM)驱动中. 然而,在转速−电流双闭环控制系统中,传统DPCC在转速外环采用比例积分(PI)控制,其扰动抑制能力有限. 此外,DPCC依赖于精确的PMSM数学模型,而实际电机与原始模型之间的参数失配会在特定工况下导致控制精度下降. 为解决上述问题,提出了一种基于双观测器的永磁同步电机扰动抑制无差拍预测电流控制方法. 首先,在转速外环采用滑模控制(sliding mode control,SMC)结合滑模负载转矩观测器(sliding mode load torque observer,SMLTO)的方法.SMLTO能够实时跟踪负载转矩变化,并将其转化为电流值,用以补偿SMC计算出的参考电流. 其次,在电流内环采用一种基于改进型误差反馈函数的扩张状态观测器(modified extended state observer,MESO),所提出的误差反馈函数具有较低的计算复杂度. 该MESO能够估计由参数失配引起的未知扰动,并在DPCC方法中对参考电压进行补偿. 最后,通过仿真与实验结果验证了所提方法的有效性.

     

    Abstract: Deadbeat predictive current control (DPCC) is widely applied to permanent magnet synchronous motors (PMSM) due to its rapid dynamic response and excellent tracking performance. However, for the speed-current dual closed-loop control systems, the traditional DPCC uses proportional-integral (PI) control in the speed outer loop, which has limited disturbance suppression capability. Moreover, DPCC relies on an accurate PMSM mathematical model, and parameter mismatches between the actual motor and the original model under certain conditions can degrade control accuracy. A dual-observer-based disturbance suppression DPCC method for PMSM was proposed to solve the above problems. First, a sliding mode control (SMC) combined with a sliding mode load torque observer (SMLTO) method was employed in the speed outer loop. The SMLTO can track load torque variations in real time and convert them into current values to compensate for the reference current calculated by SMC. Then, A modified error feedback function-based extended state observer (MESO) was employed in the current inner loop, where the proposed error feedback function features lower computational complexity. The MESO can estimate unknown disturbances caused by parameter mismatches and compensate for the reference voltage in the DPCC method. Finally, simulation and experimental results were conducted to verify the effectiveness of the proposed method.

     

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