定子磁链电压模型的偏移计算和反馈补偿新方法

A Novel Drift-estimated and Feedback-corrective Algorithm for Voltage Model of Stator Flux

检测定子磁链的电压模型使用的积分器,带来了积分初值问题和直流偏移问题,可能导致计算得到的磁链有大范围偏移。该文提出了一种计算磁链估计值偏移量的新方法,并通过反馈调节,来抑制并消除这个偏移。具体原理是,从反电势和磁链的相位关系出发,采用?-?轴电压实时代替?-?轴磁链表达式中的sin(?t)和cos(?t),推导出了计算?-?轴磁链输出偏移量的公式;设计了偏移量反馈调节的PI调节器,使得闭环调节后的直流和低频偏移量趋于0;最终使得由电压模型计算磁链的结果无偏移。在Matlab/SIMULINK下进行了深入的仿真研究,结果表明,该方法无论在稳态还是动态过程中,都能得到满意的磁链检测结果。通过实验验证了所提方法的正确性。

The voltage model of stator flux observer demands the integrator. The initial value issue and DC drift of the integrator could make the observed flux drift seriously. This paper proposes a novel algorithm to calculate the drift, and to eliminate it by feedback correction. According to the phase relationship in α-β reference frame between back electromotive force （back emf） and flux, the formula calculating the flux drift is derived by replacing ＇sin（cot）＇ and ＇cos（ωt）＇ in flux expression by real-time back emf. The PI units in the drift feedback channels are designed to make the value of both low frequency and DC drift approach zero, thus eliminating the observed flux drift of the voltage model observer. The simulation is performed in Matlab/SIMULINK. The simulation result shows that the algorithm proposed in this paper can suppress the drift effectively, gain satisfied detection result in both steady and dynamic condition. Finally, the experiment result given also proves the validity of the proposed algorithm.