基于U—N模型的三电平异步电机直接转矩控制的仿真研究

Simulation Study on Direct Torque Control of Three-level Asynchronous Motor Based on Module U-N

构建了基于二极管钳位式三电平逆变器的直接转矩控制仿真系统。针对直接转矩控制系统存在的转矩脉动、中点电位平衡控制和电压跳变等问题，提出优化的三电平矢量选择方法。为了解决U—I和I-N磁链观测模型易受定转子参数和转子角速度精确度的影响，该系统采用了全速度范围的U—N模型，提高了定子磁链观测的精确度。最后通过Simulink仿真验证了该模型的正确性和该算法的可行性。

Constructed a direct torque control simulation system based on diode-clamped three-level inverter. Against the problems of torque ripple, the neutral point potential balancing control and voltage jump, an optimized three-level vector selection method has been proposed. In order to reduce the influence due to the stator-rotor parameters and the rotor angular speed precision in the U- I and I-N flux observer model, the entire speed range U-N model is used to improve the accuracy of stator flux observer. Finally, the simulation results show the correctness of the model and the feasibility of the algorithm.