引入主动电阻的永磁同步电机电流环改进控制策略研究

A Modified Strategy for the Current Controller Employing Active Resistance for Permanent Magnet Synchronous Machines

在系统存在明显延时的情况下,永磁同步电机电流环的动态性能下降,甚至可能引发系统强烈振荡和不稳定,对于引入主动电阻的电流控制器来说尤其如此。针对这种情况,该文在推导了含主动电阻的电流控制器的基础上,建立了考虑延时的永磁同步电机简化模型,并利用根轨迹法分析了延时对主动电阻取值的影响,然后提出了两种分别基于改进型PI控制器和纯积分型控制器的改进控制策略。分析表明,所提出的控制策略增加了电流环的阻尼比,提高了电流环的快速性,其中纯积分型控制器的效果优于改进型PI控制器,且对参数误差的敏感性更低,实验结果验证了所提出改进方法的正确性。

The current control loop of the permanent magnet synchronous machine （PMSM） may suffer from strong oscillations or even become unstable when large time delay exists in the feedback loop, especially for a current controller employing active resistance. In order to solve this problem, a simplified PMSM model considering time delay was derived first and effects of the time delay on the active resistance gain selection were analyzed via root locus method. Then two control strategies based on a modified PI controller and a pure integral controller were proposed, respectively. Analyses show that the proposed two controllers not only increase the damping factor of the current loop but also make the dynamic responses faster. Moreover, the pure integral controller behaves better than the modified PI controller and exhibits less sensitivity to inaccurate motor parameters. All the theoretical analyses are verified by experimental results.