异步电动机铁耗对直接转矩控制性能的影响及补偿方法

传统直接转矩控制器没有考虑异步电动机铁耗,造成转矩控制性能下降。在两相静止αβ坐标系下建立了考虑铁耗的异步电动机动态等效数学模型。基于不考虑与考虑铁耗的电机模型,对传统DTC控制器控制性能进行了对比分析,结果表明铁耗导致传统转矩估算结果与输出转矩存在偏差,造成输出转矩无法达到参考给定转矩。本文基于考虑铁耗的异步电动机动态等效数学模型,提出一种铁耗补偿器,以校正传统转矩估算结果,使估算转矩更接近于实际输出转矩,提高了转矩控制性能。实验结果验证了改进后的DTC控制器的有效性,可提高造纸业卷绕传动等的张力转矩控制性能,进而提高产品质量。

考虑铁损补偿的异步电机最大效率矢量控制系统

异步电机铁损主要产生于定子铁心，铁损会使转子电流和转子磁通相互干扰，影响控制精度。本文把电机最大运行效率与考虑铁损的矢量控制有机结合，提出考虑铁损补偿的异步电机最大效率矢量控制新方法，对提案的控制系统进行数学建模，给出控制系统结构，并对该控制系统进行仿真研究，验证了该模型的正确性。

用FeK_x射线补偿方法测量煤灰分的研究

研究了煤中铁含量变化对煤灰分测量的影响和铁补偿方法测量煤灰分的基本原理。推导了铁补偿方法测灰的数学方程和多元函数常系数的回归拟合方法。借助于平衡滤光片的闪烁探测器建立了一套测灰装置。

Ferrimagnetic Properties of Bond Dilution Mixed Blume-Capel Model with Random Single-Ion Anisotropy

We study the ferrimagnetic properties of spin 1/2 and spin-1 systems by means of the effective field theory. The system is considered in the framework of bond dilution mixed Blume-Capel mode/ （BCM） with random single-ion anisotropy. The investigation of phase diagrams and magnetization curves indicates the existence of induced magnetic ordering and single or multi-compensation points. Special emphasis is placed on the influence of bond dilution and random single-ion anisotropy on normal or induced magnetic ordering states and single or multi-compensation points. Normal magnetic ordering states take on new phase diagrams with increasing randomness （bond and anisotropy）, while anisotropy induced magnetic ordering states are always occurrence no matter whether concentration of anisotropy is large or small. Existence and disappearance of compensation points rely strongly on bond dilution and random singleion anisotropy. Some results have not been revealed in previous papers and predicted by Néel theory of ferrimagnetism.