查询词典 harmonic analysis

The result indicates that the harmonic detection means based on instantaneous reactive power theory can detect harmonic and reactive component in three-phase current precisely and real-time, to supply reliable harmonic and reactive current for harmonic restraint and reactive power compensation.

仿真结果表明：基于瞬时无功功率理论谐波检测方法可以准确、实时地检测出三相电流中的谐波电流及无功电流，可为抑制谐波和无功补偿提供可靠的谐波及无功电流分量。

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。

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 mathematical methods to calculate the theoretical models of satellite magnetic anomalies, spherical harmonic analysis, spherical cap harmonic analysis, rectangular harmonic analysis and equivalent source method, were introduced in this paper.

本文介绍了计算卫星磁异常理论模型的数学方法，即球谐分析方法、冠谐分析方法、矩谐分析方法和等效源方法。

However, because of the positive sequence of fundamental frequency, there are still some shortages for wavelet transform in the use of harmonic measurement of three-phase dissymmetrical system. A new approach of harmonic measurement based on Period-interleaving of MALLAT arithmetic for dissymmetrical system is put forward. Analysis and experiment based on TMS320LF2407 Digital Signal Processor are made. And the result of experiment reveals that the proposed method based on Period-interleaving is valid in the use of harmonic measurement of three-phase dissymmetrical system.

但是，目前小波变换在三相不对称系统的谐波检测中存在着无法分离基波正序信号的不足，本文就此提出了一种用于三相不对称系统的基于周期交错的小波MALLAT多分辨率分解的测量方法，详细介绍了该算法的原理、流程及计算公式，同时以TMS320LF2407数字信号处理器为核心建立了实验系统对该算法进行了实验，实验结果证明该周期交错－小波变换算法可以有效地检测出三相不对称系统中的有害电流。

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。

Then, based on the analysis of some common method for harmonic detection, a new method to measure the harmonic is presented by building a harmonic measure model with nerve network.

然后在对常用的谐波检测方法进行深入分析的基础上，提出了利用神经网络建立谐波测量模型的方法。

First the paper introduces harmonic problematic research history and status, expounding harmonic elimination meaning, then to the point introduced mostly measure of harmonic elimination ,and compared analysis every kinds APF research status.

中文摘要：首先介绍谐波问题的研究历史和现状，阐述谐波治理的意义，然后扼要介绍谐波治理的主要措施，并对其中各种有源滤波器APF的研究现状进行比较分析。

Article 144 The Government of the Hong Kong Special Administrative Region shall maintain the policy previously practised in Hong Kong in respect of subventions for non-governmental organizations in fields such as education, medicine and health, culture, art, recreation, sports, social welfare and social

第一百四十四条香港特别行政区政府保持原在香港实行的对教育、医疗卫生、文化、艺术、康乐、体育、社会福利、社会工作等方面的民间团体机构的资助政策。原在香港各资助机构任职的人员均可根据原有制度继续受聘。

Small wonder, then, that the Chinese spend more in the shop than any other group of foreign visitors do .

这样的小惊喜，使中国顾客比任何国家的人消费得更多。