基于改进型有限控制集模型预测的永磁电机直接转矩控制

Direct Torque Control of Permanent Magnet Motor Based on Improved Finite Control Set Model Predictive Control

采用直接转矩控制的永磁同步电机驱动系统存在转矩脉动较大的问题。为了解决该问题,提出了一种基于改进型有限控制集预测的永磁电机直接转矩控制。新型控制策略结合使用了有限控制集模型预测控制和李亚普洛夫理论,以尽量减少转矩脉动。将两电平拓扑变频器的8个空间矢量作为一个有限控制集,用于控制永磁同步电机输出转矩,设计了一个综合考虑转矩误差、最大转矩电流比和电流限制的成本函数。和传统的有限控制集控制模型预测不同,新构建的成本函数采用了李亚普洛夫函数来估计每个电压空间矢量的占空比,同时引入了补偿实现了固定开关频率控制。最后通过对比试验验证了新型控制策略的有效性。

The permanent magnet synchronous motor drive system has the problem of torque ripple with direct torque control. In order to solve this problem, a direct torque control of permanent magnet motor was proposed based on improved finite control set model predictive control. The new control strategy combined finite control set model predictive control and Lyapunov theory to minimize the torque ripple. The eight space vector of the two-level inverter was used as a finite control set, which was used to predict the torque of permanent magnet synchronous motor. A cost function considering torque error, maximum torque per ampere and current limitation was designed. Different with the traditional finite control set model pre- dictive control, the novel cost function using the Lyapunov function to estimate each voltage space vector duty ratio, and it also belongs to the fixed switching frequency with compensation. The effectiveness of the new control strategy is verified by the permanent magnet synchronous motor drive system experiments.