基于扩张状态观测器的PMSM三电平无模型预测控制

Model-free predictive control of three-level inverter-fed PMSM based on extended state observer

针对传统永磁同步电机三电平控制策略由于参数变化导致系统性能下降的问题,提出一种基于扩张状态观测器的无模型预测电流控制方法来增强系统的鲁棒性。首先,建立系统超局部模型实现未来电流状态的预测,其中不涉及任何电机参数,解决了参数变化影响系统性能的问题;接着,针对系统总扰动,设计d、q轴扩张状态观测器估计超局部模型中的非线性部分;然后,通过价值函数筛选出最优电压矢量,并利用小矢量的冗余特性实现中点电位平衡控制;最后,在DSP实验平台上进行传统三电平模型预测电流控制、无模型预测电流控制及所提出方法的对比实验,实验结果表明所提出方法具有较好的动稳态性能并且有效提高了三电平驱动系统的抗扰动能力。

In order to address the problem that the system performance of traditional control strategy of three-level inverter-fed permanent magnet synchronous motor decreases due to parameter changes,a model-free predictive current control method based on extended state observer is proposed to enhance the robustness of the system.Firstly,the ultra-local model of the system is established to predict the future current state,which does not involve any motor parameters and solves the problem that parameter changes affect the system performance.Then,for the total disturbance of the system,dq-axes’expanded state observers are designed to estimate the nonlinear part of the ultra-local model.Furthermore,the optimal voltage vector is selected by cost function,and the balance control of midpoint potential is realized by using the redundancy characteristic of small vector.Finally,comparative experiments are conducted on a DSP experimental test rig,in terms of the traditional three-level model predictive current control,model-free predictive current control and the proposed method.The experimental results verify that the proposed method has preferable dynamic and steady-state performance and improves the anti-disturbance ability of the three-level drive system effectively.