查询词典 spheroidal harmonic function

Voltage of active power filter can be controlled by system harmonic current, load harmonic current ,harmonic current of spur track, load harmonic voltage, or combination of them, further more, a comparison research on different control strategies is put forward, and the control strategy of ideal filtering is achieved at last.

HAPF的谐波电压可以受控于系统谐波电流、负载谐波电流、滤波支路谐波电流、负载谐波电压或它们的组合，本文对不同的控制策略进行比较，最后得出理想滤波控制策略。

The voltage of active power filter can be controlled by system harmonic current, load harmonic current ,harmonic current of spur track, load harmonic voltage, or combination of them. Further more, a comparison research on different control strategies is put forward, the control strategy of ideal filtering is got ,and the system control strategy is determined at last.

HAPF的谐波电压可以受控于系统谐波电流、负载谐波电流、滤波支路谐波电流、负载谐波电压或它们的组合，本文对不同的控制策略进行比较，最后得出理想滤波控制策略，最终确定HAPF的系统控制策略。

By study, majority of the research productions and theoretical papers are about how to control harmonic, and the harmonic analysis methods that were introduced are generally applied in large power system, these harmonic analysis methods usually use harmonic network's mathematic model (the conductance and susceptance matrix of the node). But because of the dissymmetry of some elements in power system, the mathematic model is very complex, so it is very complicated to calculate by these methods, we commonly combine with computer and use them to analyze large power system.

通过学习和了解，现有的研究成果和理论文章多数是介绍谐波的治理方法，而介绍谐波分析方法的论文一般是针对大型电力系统进行分析和研究的，这些谐波分析方法通常利用谐波网络的数学模型（谐波网络的节点导纳矩阵）进行分析，由于电力系统中的某些元件的不对称性，使得数学模型复杂，计算起来极为繁琐，因此，一般结合计算机用于分析大型电力系统。

This problem is also important and valuable in Nonlinear Optics. It will be very helpful to understand how the aberrations affect the course of three- wave mixing, such as the change of conversion efficiency, the distribution of intensity and phase.Small signal solution of aberrated second harmonic generation is deduced from three-dimension three wave coupling functions. The numerical work gives out lot of results of different aberrations. The effects of the fundamental waves aberrations, which will change the conversion efficiency, distribution of intensity and phase in the frequency conversion, is analyzed. It shows that when walk-off and diffraction effects could be ignored approximately estimation of the phase distribution of second-harmonic wave could be done. The far field divergent angle and second moment radius of harmonic wave will vary with the aberration of fundamental wave, but the far field divergent angle will be obviously smaller than that of fundamental wave. The phase distribution of both fundamental and harmonic wave is measured using Hartmann-Shack wave front sensor in the experiment with 1064nm and 790nm lasers, respectively. Results are given.

首次从三维三波相互作用方程组推导得到了位相畸变光束倍频的小信号解；通过建立国防科学技术人学研究生院学位论文三维数值模型，编写相应仿真程序，首次得到了位相畸变光束倍频过程的大量计算结果，深入细致地研究了位相畸变光束经非线性光学频率变换后谐波的转换效率、光强分布、位相分布以及影响它们的各种因素；得出谐波的远场发散角和光斑二阶矩的变化规律会因为基波像差的不同而不同，但谐波的远场发散角明显地比相应基波的小的结论；得到了在走离效应和衍射效应等影响许多因素可以忽略的情况下，位相畸变传递到二次谐波的估算式；举例分析了KDP三倍频方案中，基波位相畸变对二次谐波和三次谐波的影响；实验工作中，用哈特曼一夏克传感器分别对IO64nm倍频过程和790飞秒超短脉冲倍频过程中的基波和谐波的位相分布进行了测量，给出了相应结果。

Small signal solution of aberrated second harmonic generation is deduced from three-dimension three wave coupling functions. The numerical work gives out lot of results of different aberrations. The effects of the fundamental wave's aberrations, which will change the conversion efficiency, distribution of intensity and phase in the frequency conversion, is analyzed. It shows that when walk-off and diffraction effects could be ignored approximately estimation of the phase distribution of second-harmonic wave could be done. The far field divergent angle and second moment radius of harmonic wave will vary with the aberration of fundamental wave, but the far field divergent angle will be obviously smaller than that of fundamental wave. The phase distribution of both fundamental and harmonic wave is measured using Hartmann-Shack wave front sensor in the experiment with 1064nm and 790nm lasers, respectively. Results are given.

首次从三维三波相互作用方程组推导得到了位相畸变光束倍频的小信号解；通过建立三维数值模型，编写相应仿真程序，首次得到了位相畸变光束倍频过程的大量计算结果，深入细致地研究了位相畸变光束经非线性光学频率变换后谐波的转换效率、光强分布、位相分布以及影响它们的各种因素；得出谐波的远场发散角和光斑二阶矩的变化规律会因为基波像差的不同而不同，但谐波的远场发散角明显地比相应基波的小的结论；得到了在走离效应和衍射效应等影响许多因素可以忽略的情况下，位相畸变传递到二次谐波的估算式；举例分析了KDP三倍频方案中，基波位相畸变对二次谐波和三次谐波的影响；实验工作中，用哈特曼-夏克传感器分别对1064nm倍频过程和790飞秒超短脉冲倍频过程中的基波和谐波的位相分布进行了测量，给出了相应结果。

The principle of the novel single-phase hybrid active power filter is described in detail. Based on the above analysis, Kalman filtering approach for estimation of harmonics is presented to improve the speed and precision of harmonic detection, and it also can avoid the influence made by voltage distortion on harmonic detection. A new current control strategy based on energy balance is presented to regulate the active part absorbing or releasing active power and control the inverter to produce current opposite to the harmonic current reflowing in injection branch, the above method combined with harmonic current tracking control that keeps the stabilization of dc-side voltage and improve the reliability of the system.

并详细分析了系统的滤波原理，提出了基于卡尔曼增益自调整的改进型动态谐波含量估计方法，能够快速准确的跟踪检测电网谐波电流，并且克服了电力机车等冲击性负荷引起的电网电压畸变对谐波检测精度的影响；提出了基于逆变器两侧能量平衡的电流控制方法使有源部分吸收或释放一定有功或无功功率及产生与注入支路回灌谐波电流相反的抑制电流，然后联合电网谐波电流跟踪控制以获得系统参考信号，保证了直流侧电压的稳定，提高了装置可靠性，增强了系统滤波性能。

After having compared the cupola furnace with electric arc furnace on the characteristics of the process of producing spheroidal graphite cast iron steel ingot module and their application effects, the results show that it will prolong the life of steel ingot module and improve the quality of steel ingot by applying arc furnace to melt spheroidal graphite cast iron steel ingot module.

电弧炉技术在球墨铸铁钢锭模生产上的应用赵海兵任元和李梅曹志张涛摘要将冲天炉和电弧炉这两种生产球墨铸铁钢锭模的工艺特点及应用效果进行对比，结果表明，采用电弧炉冶炼球墨铸铁钢锭模能够提高钢锭模使用寿命，改善钢锭质量。关键词球墨铸铁模耗A

It has harmonic analysis function and power energy accumulation function. It can analyze voltage, 2-50 times harmonic capacity of current, total harmonic capacity.

具有谐波分析功能，能同时分析电压、电流2～40次谐波含量及总谐波含量；电能累计功能。

Secondly, contraposes the limitation of the traditional harmonic current detecting method based on neural network, presents the method that combines the neural network and auto adaptive harmonic current detecting method based on the principle of noise each other eliminating.As the characteristics that are small calculative quantity, fast converge, without local minimal point of Redial Basis Function, this dissertation forms a new harmonic current detecting method based on RBF.

其次，针对传统的谐波电流检测方法的缺陷，提出将神经网络与基于噪声抵消原理的自适应谐波检测相结合，利用径向基函数运算量小、收敛快、无局部极小值等优点，构造了一种基于径向基函数神经网络的谐波电流检测方法，仿真结果表明该检测方法具有很好的动态响应及畸变电流检测精度。

Though comparing Canny operator and center B spline dyadic wavelet, the following conclusion is proven in this dissertation: a Center B spline function has tight support and Canny operator hasn't. b Center B spline function asymptotic convergence to Gaussian function and the derivative of Center B spline function asymptotic convergence to Canny operator. c The derivative of fourth order center spline B function is more suitable as a optimal edge detector than Canny operator. d Center B spline function can balance the smoothing and approximation of original data, and the fourth center B spline function is the only optimal solution of two order smoothing problem. e The error between the valve of time-frequency uncertainty of the fourth center B spline function and the lower bound of time-frequency uncertainty does not exceed 0.143% of the lower bound. f The derivative of center spline B function can construct a stability dyadic wavelet and can give a fast algorithm for multiscale edge detection, but Canny operator can do neither.

作者给出了Canny算子与中心B样条二进小波严格的比较证明，得出如下结论：a中心B样条函数具有紧支集，Canny算子不具有紧支集。b中心B样条函数的极限收敛于高斯函数，中心B样条函数的导数收敛于Canny算子。c四阶中心B样条函数的导数比Canny算子更接近最佳边缘检测滤波器。d中心B样条函数比高斯函数更能兼顾对原函数平滑和逼近的折中要求，并且四阶中心B样条函数是二阶逼近问题的唯一最优解。e四阶中心B样条函数的时频测不准关系值与时频测不准关系下界的逼近误差不超过0.143％。f中心B样条函数的导数可以构成稳定的二进小波，存在快速的多尺度算法；而Canny算子不构成稳定的二进小波，无法给出快速的多尺度算法。

A strange and mysterious deep sea creature.

一种奇异、神秘的深海生物。

It's a yellow rectangle .

这是黄色的长方形。