A virtual sieving experimental simulation system was built using physical simulation principles.The effects of vibration frequency and amplitude,the inclination angle of the screen-deck and the vibration direction ang...A virtual sieving experimental simulation system was built using physical simulation principles.The effects of vibration frequency and amplitude,the inclination angle of the screen-deck and the vibration direction angle of screen on single particle kinematics were predicted.Properties such as the average velocity and the average throw height were studied.The results show that the amplitude and the angle of vibration have a great effect on particle average velocity and average height.The vibration frequency and the screen-deck inclination angle appear to have little influence on these responses.For materials that are difficult to screen the vibration frequency and amplitude,the screen-deck inclination angle and the vibration angle should be set to 14 Hz,6.6 mm,6° and 40°,respectively,to obtain optimal particle kinematics.A screening process can be simulated reliably by means of a virtual experiment and these results provide references for both screening theory research and sieving practice.展开更多
大量电力电子设备的接入导致电力系统中背景谐波波动增大,进而影响谐波阻抗估计的准确性。针对这一问题,该文提出一种基于窗宽优化与数据筛选原理的系统谐波阻抗估计方法。首先,在相关系数数据中引入标准差的指标动态调整窗宽,得到满足...大量电力电子设备的接入导致电力系统中背景谐波波动增大,进而影响谐波阻抗估计的准确性。针对这一问题,该文提出一种基于窗宽优化与数据筛选原理的系统谐波阻抗估计方法。首先,在相关系数数据中引入标准差的指标动态调整窗宽,得到满足筛选样本数量的计算数据,然后利用PCC(point of common coupling)点处谐波电流与系统侧谐波电流呈弱相关的特性筛选出相应数据段,最后引入正则化项进行系统侧谐波阻抗的计算。通过仿真分析和数据计算,将所提出的方法与4种常用方法进行了比较,可以得出当背景谐波波动较大时,该方法可以减少系统谐波阻抗计算的误差,有较高的估计精度。展开更多
基金support from the Innovative Research Groups of the National Natural Science Foundation of China (No.50921002)the National Natural Science Foundation of China (Nos.50574091 and 50774084)+1 种基金the "333 Project" Foundation of Jiangsu Provincethe Key Laboratory of Coal Processing & Efficient Utilization,Ministry of Education Foundation (No.CPEUKF 08-02) for this work
文摘A virtual sieving experimental simulation system was built using physical simulation principles.The effects of vibration frequency and amplitude,the inclination angle of the screen-deck and the vibration direction angle of screen on single particle kinematics were predicted.Properties such as the average velocity and the average throw height were studied.The results show that the amplitude and the angle of vibration have a great effect on particle average velocity and average height.The vibration frequency and the screen-deck inclination angle appear to have little influence on these responses.For materials that are difficult to screen the vibration frequency and amplitude,the screen-deck inclination angle and the vibration angle should be set to 14 Hz,6.6 mm,6° and 40°,respectively,to obtain optimal particle kinematics.A screening process can be simulated reliably by means of a virtual experiment and these results provide references for both screening theory research and sieving practice.
基金Acknowledgements： This work is supported by National Natural Science Foundation of China （No. 60673084） and Hunan Provincial Natural Science Foundation of China （No. 06JJ4075）.
文摘大量电力电子设备的接入导致电力系统中背景谐波波动增大,进而影响谐波阻抗估计的准确性。针对这一问题,该文提出一种基于窗宽优化与数据筛选原理的系统谐波阻抗估计方法。首先,在相关系数数据中引入标准差的指标动态调整窗宽,得到满足筛选样本数量的计算数据,然后利用PCC(point of common coupling)点处谐波电流与系统侧谐波电流呈弱相关的特性筛选出相应数据段,最后引入正则化项进行系统侧谐波阻抗的计算。通过仿真分析和数据计算,将所提出的方法与4种常用方法进行了比较,可以得出当背景谐波波动较大时,该方法可以减少系统谐波阻抗计算的误差,有较高的估计精度。
