[关键词]
[摘要]
【目的】为提高永磁同步电机(PMSM)调速系统的抗干扰能力,本文提出了一种具有固定开关频率的带扰动补偿的预测速度控制(PSC)策略。其中,速度环采用PSC,并对扰动进行补偿;电流环采用比例积分(PI)控制。【方法】首先,依据PMSM的机械运动方程推导出实现参考速度的q轴给定电流。为了更精确地跟踪给定q轴电流,本文采用机械运动方程的二阶泰勒展开式,其精度高于一阶前向欧拉离散化。其次,传统的滑模观测器依靠较大的开关增益来确保观测误差在有限的时间内收敛为零,但较大的开关增益会带来严重的抖振现象。因此,本文提出了一种改进的滑模扰动观测器(SMDO),其在Luenberger观测器的基础上增加了一个额外的开关项,不需要很大的开关增益。然后,为了进一步提高PSC的抗干扰性能,在PSC反馈部分的基础上引入了前馈干扰补偿,提出了PSC+SMDO的控制方法。最后,在以dSPACE DS1103为控制核心的试验平台上进行试验。【结果】试验结果表明:所设计的改进SMDO能够准确估计负载扰动,并将扰动信息实时反馈给速度控制器,实现无稳态误差运行;所设计PSC+SMDO速度控制器具有较强的抗干扰性能和跟踪性能,在参数摄动时,基于自抗扰控制(ADRC)的速度控制器受参数变化影响,而PSC+SMDO速度控制器仍能保持良好的鲁棒性;在PSC+SMDO速度控制器下,电机a相电流总谐波失真(THD)为3.44%,分别比PSC、ADRC速度控制器下的a相电流THD低2.21%、4.69%。【结论】与PSC、ADRC以及PI控制器相比,所设计的PSC+SMDO控制器能很好地提高PMSM调速系统的动态响应性能和抗干扰性能。
[Key word]
[Abstract]
[Objective] To improve the anti-disturbance capability of the speed control system for permanent magnet synchronous motor (PMSM), this paper proposes a predictive speed control (PSC) strategy with fixed switching frequency and disturbance compensation. The speed loop adopts PSC with disturbance compensation, while the current loop adopts proportional integral (PI) control. [Methods] Firstly, the q-axis reference current for realizing the target speed was derived from the mechanical motion equation of the PMSM. To enhance the accuracy of q-axis current tracking, a second-order Taylor expansion of the mechanical motion equation was proposed, which proved to be more precise than first-order forward Eulerian discretization. Secondly, traditional sliding mode observers rely on large switching gains to ensure the observation errors converge to zero within a finite period of time. However, these large switching gains often lead to severe jitter phenomena. Therefore, an improved sliding mode disturbance observer (SMD
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[基金项目]
国家自然科学基金项目(51407035)