"电力电子变流电路的谐波分析与无源滤波器设计:提升电磁兼容性和能质量"

需积分: 19 6 下载量 130 浏览量 更新于2024-03-13 收藏 1.76MB DOCX 举报
With the continuous advancement of power electronics technology, power electronic devices have been widely used in modern power systems. However, the emission of harmonics from these devices poses a significant challenge to the electromagnetic compatibility performance of power systems. In order to address the potential electromagnetic compatibility issues that power electronic devices may bring to power systems, this paper analyzes the harmonic emission characteristics of power electronic circuits and designs a passive filter to eliminate the harmonics generated by power electronic circuits. The effectiveness of the filter is verified through simulation using MATLAB/Simulink software. The simulation results demonstrate that the theoretical analysis of harmonic emission characteristics aligns with the actual harmonic emission characteristics of power electronic devices. The passive filter designed in this paper effectively removes the harmonics emitted by power electronic devices. The research presented in this paper provides theoretical guidance for improving the power quality and electromagnetic compatibility performance of modern power systems. Keywords: power electronics technology; harmonics; passive filter; electromagnetic compatibility In conclusion, the analysis and design of passive filters for power electronic converters is crucial for mitigating the impact of harmonic emissions on power systems' electromagnetic compatibility and power quality. By understanding the harmonic emission characteristics of power electronic circuits and designing effective passive filters, it is possible to enhance the overall performance and reliability of modern power systems. This research contributes to the advancement of electrical engineering in the field of electromagnetic compatibility and power quality, providing valuable insights for future developments in the power electronics industry.
2019-07-23 上传
在对电网谐波治理和无功补偿时,需要实时检测分析电网中的谐波和无功电流,以便对电网中的谐波电流进行抑制和补偿无功功率。本文对小波变换算法在电网谐波电流检测中的应用做了研究,该算法利用mallat分解算法得到各频带的小波分解系数,然后将分解得到的小波系数进行单独重构,这样就可以分离出基波电流与各谐波分量。仿真与实验结果表明该方法可以很好的将基波电流与各谐波分离出来,能达到谐波电流实时检测的要求。   在电网供电系统中,电网电压是正弦交流电压,通常为50 Hz 。当电网向电阻、电感、电容器等线性负载供电时,电流波形不变,仍为交流电。然而,当电网电压施加到非线性负载(如二极管整流器或交流电压调节器)时,电流波形失真,除了基本分量之外还包含谐波分量。产生谐波的负载装置也是消耗基本无功功率的装置,它们在正常运行时给电力系统和电力用户带来危害。综合国内外的研究现状,本文将现有谐波测量和分析的主要方法分四种: 基于傅立叶变换的谐波检测方法; 基于瞬时无功功率理论的谐波检测方法; 基于人工神经网络的谐波分析和检测方法; 基于小波变换的谐波分析与检测方法。   瞬时无功功率理论检测法、神经网络法是通过分析信号的时域信息,得出信号的基本参数。傅里叶变换及其改进算法是通过将时域变换为频域信息进行分析处理,降低了信号分析的难度[3]。很多情况下,要求不仅能够获取信号在时域和频域的全貌而且要得悉信号在某些时刻的局部特征,而单纯的时域或频域分析均无法满足此要求,有学者提出了小波变换。小波变换能够通过信号频率来调整时频窗口,能精确定位信号的时间和频率,从而能够更准确的检测电网谐波电流。本文通过构建典型的电网谐波信号模型,利用mallat 分析方法对谐波信号进行检测和分析,仿真结果表明此方法具有良好的时频局部化特性,适合于稳态谐波和时变谐波的检测分析。