查询词典 harmonic analysis

To reduce the influence of an unsynchronized sample sequence on FFT and improve the precision of harmonic in a power system, the harmonic estimation based on interpolation FFT algorithm is proposed. The estimation based on five coefficients of Rife-Vincent window is discussed in detail and the formulas for estimating harmonic patameters are deduced.

由于快速傅里叶变换在非同步采样时存在较大的误差，无法直接用于电力系统谐波分析，本文提出了一种基于五项窗Rife-Vincent插值FFT算法的谐波参数估计的新方法，并推导了其谐波参数估计公式。

Electric power system harmonic is one of the most important parameters. With the development of electric power and electron technology, a number of the nonlinear loads and all kinds of commutating equipments are widely applied in every walk of life, what they bring a mass of harmonic current make the content of harmonic increase in the power system and quality of power drop.

电力系统谐波是电能质量的重要参数之一，随着电力电子技术的发展，大量的非线性负载和各种整流设备被广泛的应用于各行各业，使电网谐波含量大大增加，电能质量下降。

The effect of pole-arc coefficient、 air-gap、 damper winding and magnet circuit saturation for no-load property of harmonic winding by it . So, in this article, we bring forward a new idea and method to analyze no-load property of harmonic winding of synchronous generator by third harmonic excitation.

根据三段法，分析了极弧系数、气隙、阻尼绕组和磁路饱和等因素对谐波空载特性的影响，为分析谐波励磁同步发电机谐波绕组空载特性提供了一种新的思路和分析方法。

High-order harmonic radiation with noble gas and N〓 in static gas target has been obtained, and the effects on high-order harmonic efficiencies due to laser intensities , polarization, gas densities, confocal parameter, media characteristic and phase mismatch have been discussed. The experimental results show that the high-order intensities grow with the incident laser intensities and gas densities, and high-order harmonic signals amplify in the same time.

高次谐波辐射是强场物理中与电离过程相伴而生另一种重要过程，本文利用飞秒激光在静态气室中获得全部的稀有气体原子以及氮双原子分子5到21次的谐波发射，着重讨论了激光功率密度、激光偏振、气体密度、共焦参数、介质本身以及相位失配对高次谐波转换效率的影响。

The selective harmonic compensation based on FFT is proved effective to suppress the harmonic amplification by field operation of shunt APF compensating harmonic current generated by electric load in office building.

经过对办公楼负载的实际并网谐波补偿实验证明基于FFT的有选择谐波补偿方法对于抑制谐波放大是有效的。

The static, modal and harmonic analysis was performed in ANSYS; static capacitance, natural frequencies for the short circuit case and the open circuit (anti-resonance) case, dynamic resistance, frequency at half-power point, dynamic inductance and mechanical quality factor were computed via static, modal analysis and harmonic analysis.

为了加速低频超声雾化栽培喷头的设计制造进程、降低研发成本，该文提出了其阻抗的测试原理电路图，建立了阻抗分析的有限元模型，在大型通用有限元分析软件ANSYS中进行了静态分析、模态分析和谐响应分析。

Students will learn Regression Analysis, Multivariate Analysis of Variance, Discriminate Analysis, Categorical Data Analysis, Principal Component Analysis, Canonical Correlation Analysis, Factor Analysis, Cluster Analysis, and Multidimensional Scaling Analysis.

同学们将在本课程中学习回归分析、多变量共变数分析、鉴别分析、类别资料分析、主成分分析、正典相关分析、因素分析、集群分析、多元尺度分析常用的多变量分析模式。

Installation, test and practical measurements of the whole system also have been implemented. Studied the various methods of digital monitoring dielectric loss for transformer bushes: harmonic analysis method. Sine-shape parameters method and integration method, states the principles of the three methods, its computational formula has been inferred and compared. Among them, harmonic analysis method was used to test practically both in lab and on site.

研究了变压器套管介质损耗的数字化监测方法：谐波分析法、正弦波参数法和积分法，论述了三种方法的监测原理，详细推导了各种方法的计算公式，比较了各种方法的优缺点，并采用谐波分析法在实验室和现场进行了测试，其结果表明该方法在介损测试中具有较高的稳定性和准确性。

Chapter four studies the chaotic responses in a system consisting of simple pendulum and harmonic oscillator under bounded noise excitation. Firstly, the Melnikov function of the two-degree-of-freedom system under Hamiltonian perturbation is derived. The essential condition of the autonomous system for the probable onset of chaos is obtained, the Poincare maps of the system under small Hamiltonian perturbation and the effect of increasing perturbation on the Poincare maps are studies. Then for the non-autonomous system under damping and harmonic or bounded noise excitation, the largest Lyapunov exponent and Poincare maps are calculated. From the analysis of the largest Lyapunov exponent, the critical criterion for the onset of chaos, and the conclusion that the threshold of bounded noise amplitude for the onset of chaos in the system increases as the intensity parameter of Wiener process increases are obtained. The result from the analysis of Poincare maps is in agreement with that obtained from the Largest Lyapunov exponent. The effect of varying damping coefficient and intensity parameter of Wiener process is also analyzed.

第四章研究了有界噪声激励下的两自由度单摆—谐振子系统的混沌运动，首先推导了该两自由度系统仅在Hamilton扰动下的Melnikov函数，得到该自治系统可能产生混沌的必要条件；研究了该系统在小的Hamilton扰动和增大摄动情形下的Poincare截面；然后对有阻尼、谐和或有界噪声激励下的非自治系统数值计算了其最大Lyapunov指数和Poincare截面；从Lyapunov指数分析得到了这个两自由度系统产生混沌运动的临界条件及产生混沌的临界激励幅值随Wiener过程强度参数值的增大而增大的结论，Poincare截面分析的结果亦符合Lyapunov指数分析的结论；研究了Wiener过程强度参数、阻尼系数变化对Poincare截面的影响。

Second, Unexpectable situation such as bad weather or apparatus problems will cause some other cases, for example, tidal level data cant be measured completely or contains great errors. Aim at these cases, according to multiple harmonic analysis method, this paper presents a new method for the iterative harmonic analysis of tides based on the least square method of continuous function, as well as the condition when this method converges.

第二、针对恶劣天气或仪器等意外情况导致潮位数据缺测或者具有重大误差等情况发生时，根据多次调和分析方法的思想，给出了基于连续函数最小二乘法的潮汐迭代调和分析方法，给出了方法收敛的条件。

In the days of sailing vessels the crew were afraid they would be becalmed on the ocean.

在使用帆船的时代，船员们担心他们会因为无风而无法在海洋上航行。

As long as foreign donors pay the PA's salary bill, few expect a new intifada.

只要外国继续为巴权力机构的薪水买单，希望发动新暴动的人便寥寥无几。