谐波

The pollution problem caused by harmonic sources to power system has become more and more serious. As traditional filter devices , passive filters can not only suppress the harmonic but also compensate the reactive power and are still a widely used measure for harmonic suppression.

摘 要 谐波源对电网的污染问题已经日益引起人们的关注，而无源滤波器作为传统的滤波装置，既可以滤除谐波，同时可以兼顾无功补偿的需要，目前仍是应用较为广泛的抑制谐波污染的措施。

Because the harmonic is harmful to the electric net and electrical equipment, it is very important to measure the harmonic accurately and restrain it. Some methods for harmonics measurement are proposed in these years.

由于谐波对电网及用电设备有诸多危害，准确测量谐波及抑制谐波就显得尤为重要。

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。

We choose the TMS320VC5402, digital signal processor, as the computing unit, filtering the sampled signal, truncating the harmonic whose frequence greater than 2500hz, then we use the window-interpolation FFT algorithm to get the refined frequence, amplitude, phase of harmonic in sampled voltage and current, other parameter such as harmonic ratio, active power, reactive power, power factor, three-phase unbalance can be also computed base one the result of window-interpolation FFT.

选用TMS320VC5402高速数字信号处理器作为运算单元，先对采样信号进行数字滤波，去除50次以上谐波分量，然后应用加窗双峰插值FFT算法计算电压电流的各次谐波频率、幅值和相位，以及谐波含有率、有功功率、无功功率、三相不平衡度等各项电能指标，同时利用锁相环电路硬件跟踪电网频率以减小采样失步度。

Especially, the inductive load and impactive load of electrical equipments bring much Var and harmoniousness to the power system. They lead to low power factor, vast harmonious component and lead to other electrical equipment deviant work.

特别是用电设备中的感性负荷和冲击负荷给电网带来了大量的无功和谐波，造成电网功率因数降低，谐波成分增大，引起本身和其它用电设备不能正常高效的工作，为此，补偿电网的无功和谐波就成为人们及其关注的课题。

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。

Then a novel control method of PAPF is proposed. PAPF with the proposed control method has excellent performance in damping of both parallel resonance and series resonance, whether the capacitor current is included in the detecting current of PAPF or not. Also the PAPF with proposed method has strong ability in harmonic compensation.

针对这种情况该文提出了一种新的PAPF控制策略，该控制策略可以在进行谐波治理的同时有效抑制负载谐波电流或者系统谐波电压造成的并联电容器与电网阻抗之间的谐振。

This paper proposed an exact identification of background harmonic voltage based on the metrical data at PCC.

本文根据PCC处实测的谐波电压和谐波电流数据，对系统的背景谐波电压进行准确辨识。

By analyzing the characteristics of the several common load harmonic sources, this paper inducted the resistance formulas, sequence resistance and sequence impedance matrixes of tri-phase universe loads, star and triangle connection loads under harmonics condition.

在分析几种常用负载谐波源特性的基础上，推导出了在谐波环境下三相通用负载、星形和三角形联结负载谐波源的阻抗计算公式、序阻抗和序导纳矩阵。

In order to solve the current differential protection's maloperation, the combined harmonic blocking criteria and the criteria based on the trace of action point are proposed.

电流互感器发生暂态饱和时，二次电流中的谐波主要是2次谐波，3次谐波含量很少。

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。。。。