随着“双碳”目标的推进,大规模新能源并网使电网背景谐波呈现强波动性,导致现有系统谐波阻抗估计方法精确度降低,进而影响谐波主导扰动源定位与后续针对性治理。因此,针对新能源场站并网场景,研究系统谐波阻抗的精确估计对解决电网谐...随着“双碳”目标的推进,大规模新能源并网使电网背景谐波呈现强波动性,导致现有系统谐波阻抗估计方法精确度降低,进而影响谐波主导扰动源定位与后续针对性治理。因此,针对新能源场站并网场景,研究系统谐波阻抗的精确估计对解决电网谐波污染问题有重要意义。从数据驱动的角度出发,在新能源场站并网点建立了谐波阻抗评估模型。首先,针对背景谐波波动干扰的非理想条件,引入伊潘涅切科夫核函数拟合背景谐波电压的概率密度函数;其次,对于系统侧谐波阻抗值的估计,提出了基于改进贝叶斯的谐波阻抗估计方法,应用贝叶斯方法评估谐波阻抗时,基于熵最大原则和自分析法确定先验均匀分布区间范围;然后,针对样本容量过大导致估计过程耗时较长的问题,提出了基于最大最小优化拉丁超立方体采样法对公共连接点(point of common coupling,PCC)的数据样本进行筛选;最后,通过MATLAB/Simulink仿真分析的计算,验证了所提系统侧阻抗估计方法在背景谐波波动干扰时具有较高精度。展开更多
Landscape pattern is a widely used concept for the demonstration of landscape characteristic features. The integral spatial distribution trend of landscape elements is interested point in the landscape ecological rese...Landscape pattern is a widely used concept for the demonstration of landscape characteristic features. The integral spatial distribution trend of landscape elements is interested point in the landscape ecological research, especially in those of complex secondary forest regions with confusing mosaics of land cover. Trend surface analysis which used in community and population ecological researches was introduced to reveal the landscape pattern. A reasonable and reliable approach for application of trend surface analysis was provided in detail. As key steps of the approach, uniform grid point sampling method was developed. The efforts were also concentrated at an example of Guandishan forested landscape. Some basic rules of spatial distribution of landscape elements were exclaimed. These will be benefit to the further study in the area to enhance the forest sustainable management and landscape planning.展开更多
文摘随着“双碳”目标的推进,大规模新能源并网使电网背景谐波呈现强波动性,导致现有系统谐波阻抗估计方法精确度降低,进而影响谐波主导扰动源定位与后续针对性治理。因此,针对新能源场站并网场景,研究系统谐波阻抗的精确估计对解决电网谐波污染问题有重要意义。从数据驱动的角度出发,在新能源场站并网点建立了谐波阻抗评估模型。首先,针对背景谐波波动干扰的非理想条件,引入伊潘涅切科夫核函数拟合背景谐波电压的概率密度函数;其次,对于系统侧谐波阻抗值的估计,提出了基于改进贝叶斯的谐波阻抗估计方法,应用贝叶斯方法评估谐波阻抗时,基于熵最大原则和自分析法确定先验均匀分布区间范围;然后,针对样本容量过大导致估计过程耗时较长的问题,提出了基于最大最小优化拉丁超立方体采样法对公共连接点(point of common coupling,PCC)的数据样本进行筛选;最后,通过MATLAB/Simulink仿真分析的计算,验证了所提系统侧阻抗估计方法在背景谐波波动干扰时具有较高精度。
文摘Landscape pattern is a widely used concept for the demonstration of landscape characteristic features. The integral spatial distribution trend of landscape elements is interested point in the landscape ecological research, especially in those of complex secondary forest regions with confusing mosaics of land cover. Trend surface analysis which used in community and population ecological researches was introduced to reveal the landscape pattern. A reasonable and reliable approach for application of trend surface analysis was provided in detail. As key steps of the approach, uniform grid point sampling method was developed. The efforts were also concentrated at an example of Guandishan forested landscape. Some basic rules of spatial distribution of landscape elements were exclaimed. These will be benefit to the further study in the area to enhance the forest sustainable management and landscape planning.
