直接转矩控制磁链低频脉动分析及抑制

本文用计算机仿真的方法,详细分析了直接转矩控制系统低频脉动的产生原因,解析了电机温升引起的定子电阻变化对定子磁链的估计精度的影响,提出用改进型磁链观测器替代传统的积分观测器;同时针对低频时逆变器开关频率过低导致转矩脉动增加的问题,细化磁链位置判别,降低传统的直接转矩控制系统的低频磁链脉动,使控制系统有更高的响应速度和更强的鲁棒性.并用Matlab/Simulink软件建立了该直接转矩系统的仿真模型,仿真结果表明了改进方案的有效性.

Analysis and Restrain of Low Frequency Ripple for Direct Torque Control of Flux Linkage

In this paper,t he reason of low frequency ripple in direct torque control system is discussed using computer simulation method, the influence of stator resistance change caused by motor temperature rise to precision of stator flux linkage compute is been analysed. The paper brings forward that the traditional integral observer should be substituted by a novel flux observer. Aiming at the increased torque ripple problem caused by low inverter switch frequency at low frequency, the paper refined the partition of flux position to decrease the low frequency flux ripple in the traditional direct torque control, which make control system have more rapid response speed and more Highly Robust. The paper set up simulation model of direct torque control system using Matlab/Simulink, the simulation result indicated the validity of the improved method.