谐波对电流互感器的传变特性及电能计量影响研究

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重庆大学硕士学位论文
英文摘要
ABSTRACT
Along with the increase in nonlinear load, harmonic content increased obviously in the grid, harmonic pollution problem is becoming more and more serious. Harmonic distortion will not only loss the service life of the transformer and cable equipment, make the protection misoperation, interference data communication, etc., will also produce a great impact on the electric energy metering. For electric energy metering, related research focus on the watt-hour meter under the harmonic measurement accuracy and measurement methods of improvement, often neglected in electric energy metering device and watt-hour meter with the effects of the use of current transformer. In the face of power grid is more and more complex signal, based on the design of the power frequency current transformer is faced with great challenge. For non-sinusoidal conditions the change characteristics of current transformer, leading to some relevant issues influence on electric energy metering, this paper carried out research, the main research content is as follows: First of all, this paper introduces the working principle of current transformer, based on its equivalent circuit are analyzed in detail the primary and secondary relationship between each parameter and the causes of error of current transformer. By the phasor diagram and the electromagnetic relationship of contrast of current transformer is deduced and the Angle difference expressions, delves into the use error formula parameters on the effect of current transformer error. Second, summarized the existing model of current transformer, the advantages and disadvantages of all kinds of model are analyzed in detail. Combined in this paper, the research content and characteristics of the model, the selection of the under the condition of non sinusoidal simulation and actual results are close to J - A and LUCUS model, prepared for the next research work. Third, the establishment of a current transformer under dc equivalent analysis model. Is deduced under the dc component of the current transformer and error calculation formula. Through calculation, the dc component of current transformer and variable error influence is very big. Active power error of fundamental wave to quantify the dc component and the relationship between the electric energy metering. To improve current transformer under dc component in variable transfer some improving
谐波对电流互感器的传变特性及电能计量影响研究计量用电流互感器电流互感器电流互感器接线图零序电流互感器电流互感器型号电流互感器选型手册电流互感器的作用电流互感器变比电流互感器原理
谐波对电流互感器的传变特性及电能计量影 响研究
重庆大学硕士学位论文 （学术学位）
学生姓名：郭 指导教师：李 专 捷 新 教授
College of Electrical Engineering of Chongqing University, Chongqing, China
May来自百度文库2014
重庆大学硕士学位论文
中文摘要
摘
要
随着非线性负载的增多，电网中的谐波含量明显增大，谐波污染问题日益严 重。谐波畸变不仅会损耗变压器和电缆等设备的使用寿命、使保护装置误动、干 扰数据通信等，还会对电能计量产生很大影响。针对电能计量，相关研究注重于 谐波畸变下电能表计量的准确性和计量方式的改进，往往忽略了电能计量装置中 与电能表配合使用的电流互感器所带来的影响。面对实际电网越来越复杂的信号， 基于工频设计的电流互感器面临着极大挑战。针对谐波畸变信号下电流互感器的 传变特性所引起的误差，进而导致对电能计量的影响的一些相关问题，本文展开 了研究，主要研究内容如下： 首先，介绍了电流互感器的工作原理，依据其等值电路详细分析了一、二次 侧各参数间的关系和电流互感器误差产生的原因。利用相量图和电磁关系得到电 流互感器的比值差和相位差表达式，针对影响电流互感器误差的一些因素做了深 入研究。 第二，对于现有的电流互感器模型进行总结归纳，详细分析各类模型的优缺 点。结合本文研究内容及模型特点，选取了谐波畸变下仿真与实际结果较为接近 的 J-A 和 LUCUS 模型，为接下来的研究作了准备工作。 第三，建立了电流互感器在直流分量下的等效分析模型。推导得到了在直流 分量下电流互感器传变误差的计算公式。经计算得知，直流分量对电流互感器的 传变误差影响很大。由基波的有功功率误差量化了直流分量与电能计量之间的关 系。对于提高直流分量下电流互感器的传变性能提出了一些改善的建议。 第四，为了在异步采样下减少频谱泄漏，采用基于 Hanning 窗的 FFT 算法， 提高谐波分析的精度。对比频率响应方法，提出一种分析谐波条件下电流互感器 传变特性的新方法，通过仿真对比发现，频率响应方法所得的结果可能不是实际 可靠的。对谐波条件下影响电流互感器传变特性的一些因素作了深入研究。 第五，考虑电流互感器非线性影响，推导了谐波有功功率误差表达式。研究 表明，电流互感器非线性所产生的相位差可能会谐波有功功率的测量带来的很大 影响，进而影响电能计量。利用 PSCAD 模拟实际情况工作环境，将电流互感器置 于谐波污染的电路中和对实际录波数据进行仿真分析，仿真结果都验证了这一结 论。 关键词：电磁式电流互感器，等效模型，直流分量，谐波畸变，电能计量
业：电气工程 学
学科门类：工
重庆大学电气工程学院
二 O 一四年五月
Impact of Harmonics on Current Transformer Characterization and energy Measurement
A Thesis Submitted to Chongqing University in Partial Fulfillment of the Requirement for the Master’s Degree of Engineering By Guo Jie Supervised by Prof. Li Xin Major:Electrical Engineering
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重庆大学硕士学位论文
英文摘要
Suggestions are put forward. Fourth, in order to reduce spectral leakage in the case of asynchronous sampling, USES the FFT algorithm based on Hanning window function, improve the accuracy of harmonic analysis. Comparative frequency response method, this paper proposes a new method of analyzing the current transformer harmonic transmission characteristics, through the simulation comparison, found that the frequency response method the results may not be practical and reliable. Impact on the harmonic conditions and variable current transformer characters made a in-depth study of some of the factors. Fifth, based on the nonlinear current transformer, this paper derived the error expression of harmonic active power. Studies have shown that nonlinear phase difference generated by the current transformer may bring the great influence of harmonic active power measurement, which affect the electric energy metering. Work environment, the conditions of PSCAD simulation current transformer in the circuit of the harmonic pollution and simulation analysis was carried out on the actual wave record data, the simulation results prove the conclusion. Keywords： electromagnetic current transformer, the equivalent model of dc component, harmonic distortion, power metering