谐波

Fluxgate sensors have the second harmonic voltage amplitude with the magnetic field strength is proportional to the adoption of second harmonic filter through phase-sensitive detector rectifier, to achieve full-wave rectifier, low-pass filter in through the phase-sensitive detector after the second harmonic into a smooth DC signal, on the one hand to the back of the circuit, on the one hand, the magnetic flux through the door to feedback regulation, the opposite magnetic field generated with the measured magnetic field, so that the work has always been zero fluxgate magnetic field, thus ensuring the most high-precision fluxgate.

磁通门传感器产生的二次谐波电压幅值与磁场强度成正比，二次谐波通过通过滤波器再通过相敏检波器整流，实现全波整流，在通过低通滤波器将相敏检波后的二次谐波转化成平滑的直流信号，一方面送到后面的电路进行，一方面通过反馈调节送到磁通门中，产生与被测磁场相反的磁场，使磁通门始终工作零磁场下，从而保证磁通门的最高精度。关键词：磁通门磁力仪，相敏检波器，磁场

The capacitance capacitors and inductors of power grid form parallel resonance circuit .It's frequency may be related to the existing power grid close to the harmonic frequencies, If there is power grid harmonic current sources, harmonic resonance caused by enlarged so that the voltage and current waveform distortion even more serious.

电容器的电容和电网的电感形成并联谐振回路，其频率可能与电网中存在的谐波频率接近，如果电网存在谐波电流源，谐振引起的谐波放大使电压和电流波形畸变更为严重。

However, harmonic analysis lays the foundation for power harmonic treatment. The paper discusses the development of a power harmonic analyzer hosed on DSP and LabVIEW, which is used to analyze and measure harmonic on real-time. The analyzer's hardware, harmonic analysis algorithm, LabVIEW software design and the implementation are alt brought forward in detail.

为了有效地检测电力谐波，并对其进行治理，本文将DSP与LabVIEW虚拟仪器技术相结合，提出了一个谐波实时测量分析仪的设计方案，同时给出了系统的硬件构成和谐波分析算法，以及LabVIEW子程序的详细设计及实现。

The wave of the harmonic winding voltage and the no-load characteristics curve of the harmonic excited synchronous generator.

得出了谐波励磁同步发电机的旋转磁场波形、谐波绕组电压波形以及谐波绕组空载特性曲线。

For mastering on-load property of the third harmonic excitation system . Thus , a new method to analyze harmonic winding no-load property curve of harmonic excitation synchronous generator , named as three-segment method , is presented in this article.

为了把握三次谐波励磁系统的空载性能，本文提出了应用三段法来分析三次谐波励磁同步发电机谐波绕组空载特性。

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。

Results indicate that:(1) by using HANTS, the researchers could get the EVI/NDVI harmonic curves, the mean VIs and the amplitude of the harmonics which then were utilized in the identification of the cultivated land, and EVI appeared to be more precise, with the overall accuracies of 97.17% and 95.99% and Kappa coefficients of 0.7938 and 0.6518, respectively.(2) Multiple cropping index was extracted by counting the number of the curve's peak; and when the threshold of the peak value of the NDVI and EVI curves were set as 0.25 and 0.20, respectively, the fallow land could be well figured out.(3) From harmonic curves, some eigenvalues, such as time of the maximum growth rate, time of peak and the value of peak can be extracted, based on which the crop types can be primarily distinguished. And EVI still performed better than NDVI in this section.

结果显示：（1）利用傅立叶谐波变换得到的EVI和NDVI时间谱曲线的谐波余项及谐波振幅对耕地进行识别，从识别精度来看，EVI要优于NDVI，识别精度分别为97.17%和 95.99%，Kappa系数分别达到0.7938和0.6518；（2）通过计算时间序列曲线的波峰数能够提取耕地的复种指数，并且在EVI和NDVI曲线波峰阈值分别设为0.20和0.25时，休耕地能较为准确地被识别出来；（3）通过提取作物生长期内曲线的VI最大增长速率时间点以及峰值时间点等信息，作物种类能被初步识别，并且EVI较NDVI具有更强的识别能力。

Harmonic measure method is the key of the measurement. In this paper, the harmonic measure method which based on the multiple frequency rotate transform theory is researched and analyzed.

谐波测量方法是谐波测量的核心环节，本文对基于倍频旋转变换理论的谐波测量方法进行了研究分析。

Keywords: Harmonics, active power filter, Fourier Algorithm, Harmonic analysis and measure, Harmonic prevention

谐波，有源滤波器滤波器，傅立叶变换，谐波分析测量，谐波抑制

Traditional instrument in harmonic measurement is the transformer with circularity form core coil, but it is influenced by direct current and saturated, so it could not be used to measure direct harmonic current.

基于Rogowski 线圈的光电直流谐波电流测量系统解决了传统谐波电流测量受直流分量影响的难题，是集光纤技术、电子技术、激光技术于一体的新型谐波电流互感器。

Since historical times,England ,where the early inhabitants were Celts, has been conquered three times .

从有历史以来，英国，在此地早期居住的是凯尔特人，已经被征服了三次。

Bluetooth OBEX File Transfer Enables the sending and receiving of files on your phone via Bluetooth.

蓝牙OBEX文件移动允许经过蓝牙传送和接受文件。。。。