电能质量在线监测系统
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摘要
近年来，电能质量问题日益引起电力部门和用户的广泛关注。为了采取合理的措施来提高电能质量，必须首先建立电能质量监测分析系统，对电能质量进行正确地检测、评估和分类。本文在总结原有的电能质量分析方法的基础上，提出采用小波变换和傅立叶变换相结合的方法进行电能质量分析。
本文首先系统地介绍了电能质量现象及其理论基础，对各种电能质量扰动的分类、定义、特征及其产生的原因进行了详细的阐述，并简要介绍了我国电能质量标准。其次，对傅立叶变换、短时傅立叶变换和小波变换这三种方法的基本原理及其在电能质量分析领域的应用现状做了探讨和比较，分析了各种方法的特点及其适用条件。进而，通过对大量典型信号的仿真分析确立了电能质量分析算法，并验证了该方法的优越性。
实际的电能质量信号可能含有高频突变部分和噪声部分。小波变换的自适应性使其对电能质量扰动信号的消噪有着传统的低通滤波器无法比拟的优点。本文采用小波消噪的方法对信号进行预处理，获得了良好的效果。
基于信号的奇异性检测理论，利用小波分解的高频系数是否具有模极大值作为区分稳态和非稳态现象的判据。利用快速傅立叶变换方法对谐波、闪变和纯正弦波等稳态现象进行分析。利用小波变换的快速算法——Mallat算法来确定非稳态扰动的持续时间和扰动波形，从而区分各种非稳态扰动现象。
最后，本文从电能质量在线监测的角度出发，采用基于小波变换和傅立叶变换的电能质量分析方法，设计了以TMS320VC33为核心的硬件监测系统，并采用C语言编程实现电能质量分析算法。
In late years, power quality issues have captured considerable attention from both utility companies and their customers in many countries. To improve the electric power quality, a monitoring and analyzing system must be established to detect, estimate and classify different disturbances. Traditional monitoring and analyzing system have put emphasis on steady voltages and currents, a new analyzing method based on wavelet transform and Fourier transform has been presented in the thesis.
In the thesis firstly the theoretical background of power quality phenomena is introduced. Secondly, three transform-based methods, which are Fourier transform, short-time Fourier transform and wavelet transform, and their applications are described and discussed in detail. Then the analysis algorithm of electric power quality is posed by massive simulation and analysis.
Real power quality signals may comprise high-frequency useful part and noise part. Self-adapting quality makes wavelet denoising prior to low-pass filter. Wavelet denoising is presented as a pre-processing tool for power quality signals in the thesis.
Based on the theory of signal strangeness detect, the maxima modulus in high frequency of wavelet resolving can be used as a criterion to classify steady and non-steady state phenomena. As to steady state phenomena, the traditional signal analysis tool FFT is used for harmonic analysis and flicker. By means of the Mallat algorithm, the lasting time and disturbance waveform can be extracted, so non-steady state interruptions can be identified exactly.
Finally, considering on-line monitoring and measurement system of power quality, based on wavelet transform and Fourier transform for power quality analysis, the hardware system is designed base on TMS320VC33, and the software is programmed in C language in the thesis.
本文首先系统地介绍了电能质量现象及其理论基础，对各种电能质量扰动的分类、定义、特征及其产生的原因进行了详细的阐述，并简要介绍了我国电能质量标准。其次，对傅立叶变换、短时傅立叶变换和小波变换这三种方法的基本原理及其在电能质量分析领域的应用现状做了探讨和比较，分析了各种方法的特点及其适用条件。进而，通过对大量典型信号的仿真分析确立了电能质量分析算法，并验证了该方法的优越性。
实际的电能质量信号可能含有高频突变部分和噪声部分。小波变换的自适应性使其对电能质量扰动信号的消噪有着传统的低通滤波器无法比拟的优点。本文采用小波消噪的方法对信号进行预处理，获得了良好的效果。
基于信号的奇异性检测理论，利用小波分解的高频系数是否具有模极大值作为区分稳态和非稳态现象的判据。利用快速傅立叶变换方法对谐波、闪变和纯正弦波等稳态现象进行分析。利用小波变换的快速算法——Mallat算法来确定非稳态扰动的持续时间和扰动波形，从而区分各种非稳态扰动现象。
最后，本文从电能质量在线监测的角度出发，采用基于小波变换和傅立叶变换的电能质量分析方法，设计了以TMS320VC33为核心的硬件监测系统，并采用C语言编程实现电能质量分析算法。
In late years, power quality issues have captured considerable attention from both utility companies and their customers in many countries. To improve the electric power quality, a monitoring and analyzing system must be established to detect, estimate and classify different disturbances. Traditional monitoring and analyzing system have put emphasis on steady voltages and currents, a new analyzing method based on wavelet transform and Fourier transform has been presented in the thesis.
In the thesis firstly the theoretical background of power quality phenomena is introduced. Secondly, three transform-based methods, which are Fourier transform, short-time Fourier transform and wavelet transform, and their applications are described and discussed in detail. Then the analysis algorithm of electric power quality is posed by massive simulation and analysis.
Real power quality signals may comprise high-frequency useful part and noise part. Self-adapting quality makes wavelet denoising prior to low-pass filter. Wavelet denoising is presented as a pre-processing tool for power quality signals in the thesis.
Based on the theory of signal strangeness detect, the maxima modulus in high frequency of wavelet resolving can be used as a criterion to classify steady and non-steady state phenomena. As to steady state phenomena, the traditional signal analysis tool FFT is used for harmonic analysis and flicker. By means of the Mallat algorithm, the lasting time and disturbance waveform can be extracted, so non-steady state interruptions can be identified exactly.
Finally, considering on-line monitoring and measurement system of power quality, based on wavelet transform and Fourier transform for power quality analysis, the hardware system is designed base on TMS320VC33, and the software is programmed in C language in the thesis.
引文
[1] 林海雪，李世林，刘惠民．电压电流频率和电能质量国家标准应用手册．北京：中国电力出版社．2001
[2] Dugan R C, et al. Electrical Power System Quality[M] . New York: McGraw-Hill, 1982.
[3] TC 77 WG6(Secretary) 110-R5, Draft Classification of Electromagnetic Environment, January 1991.
[4] IEEE Standard 1159, IEEE Recommended Practices for Monitoring Electrie Power Quality, New York, 1995.
[5] IEEE Standard 519-1992, IEEE Recommended Practices and Requirements for Harmonic Control in Electrical Power Systems, New York, 1992.
[6] Dugan R C, McGranagban M F, Beaty H W. Electrical Power Systems Quality. New York: MeGraw-Hill, 1996
[7] Warren C M. The Effect of Reducing Momentary Outages on Distribution Reliability Indices. IEEE Trans on Power Delivery, 1993,8(3): 1610—1617
[8] 林海雪．电力系统的三相不平衡．北京：中国电力出版社，1998
[9] Dugan R C. Simulation of Arc Fumace Power Systems. IEEE Trans on Industry Application, 1980, 16 (6): 813—818
[10] 吕润馀．电力系统高次谐波．北京：中国电力出版社，1998
[11] 张一中．电力谐波．成都：成都科技大学出版社，1990
[12] 水利电力部．电力系统谐波管理暂行规定(SD 126-84)．北京：水利电力出版社，1985
[13] 国家技术监督局．电能质量—公用电网谐波(GB／T 14549-93)．北京：标准出版社，1993
[14] 王越，刘晋平，李向荣．用新型静止无功发生器抑制电压闪变之研究．电网技术，1998，22(9)：61-64
[15] 祁碧茹，肖湘宁．IEC闪变仪仿真．华北电力大学学报，2000，27(1)：19-24
[16] 雷林绪．对电压波动闪变仪校验的一点看法．电网技术，1999，23(3)：41-43
[17] 蔡邠．电力系统频率．北京：中国电力出版社，1998
[18] Chui C K. An Introduction to Wavelets. New York: Academic Press, 1992
[19] 胡昌华，张军波，夏军，等．基于MATLAB的系统分析与设计—小波分析．西安：西安电子科技大学出版社，1999
[20] 王世一．数字信号处理．北京：北京理工大学出版社，1997
[21] 李庚银，陈志业，宁宇．快速傅立叶变换的两种改进算法．电力系统自动化，1997，21(12)：37-40
[22] 张伏生，耿中行，葛耀中．电力系统谐波分析的高精度FFT算法．中国电机工程学报，1999，19(3)：63-66
[23] 赵渊，钟岷秀，周念成，等．电力系统谐波分析仪算法研究．华北电力，1999，27(4)：15-17
[24] Gu J C, Yu S L. Removal of DC Offset in Current and Voltage Signals Using a Novel Fourier Filter Algorithm. IEEE Trans on Power Delivery, 2000,15(1):73-79
[25] L．科恩著．时—频分析：理论与应用．白居宪译．西安：西安交通大学出版社，1998．3
[26] Daubechies I. The Wavelet Transform, Time-frequency Localization and Signal Analysis. IEEE Trans on Information Theory, 1990,36(5):961-1005
[27] Heydt G T, Field P S, Liu C C, et al. Application of the Windowed FFT to Electric Power Quality Assessment. IEEE Trans on Power Delivery, 1999,14(4):1411-1416
[28] 程正兴．小波分析算法与应用．西安：西安交通大学出版社，1998
[29] Huang S J, Hsieh C T, Huang C L. Application of Morlet Wavelets to Supervise Power System Disturbances. IEEE Trans on Power Delivery, 1999,14(1):235-241
[30] Brito N S D, Souza B A, Pires F A C. Daubechies Wavelets in Quality of Electrical Power. Proceeding of IEEE ICHQP Ⅷ. Athens(Greece): 1998.511-515
[31] Angrisani L, Daponte P, Apuzzo M D, et al. A Measurement Method Based on the Wavelet Transform for Power Quality Analysis. IEEE Trans on Power Delivery, 1998,13(4):990-998
[32] Gaouda A M, Salama M M A, Sultan M R, et al. Power Quality Detection and Classification Using Wavelet-Multiresolution Signal Decomposition. IEEE Trans on Power Delivery, 1999,14(4):1469-1476
[33] Gaouda A M, Salama M M A, Sultan M R, et al. Application of Multiresolution Signal Decomposition for Monitoring Short-Duration Variations in Distribution Systems. IEEE Trans on Power Delivery, 2000,15(2):478-485
[34] Santoso S, Powers E J, Grady W M. Power Quality Disturbance Data Compression Using Wavelet Transform Methods. IEEE Trans on Power Delivery, 1997,12(3):1250-1255
[35] Littler T B, Morrow D J. Wavelets for the Analysis and Compression of Power System Disturbances. IEEE Trans on Power Delivery, 1999,14(2):358-364
[36] Possion O, Rioual P, Meunier M. New Signal Processing Tools Applied to Power Quality Analysis, IEEE Trans on Power Delivery, 1999,14(2):561-566
[37] 秦前清，杨宗凯．实用小波分析．西安：西安电子科技大学出版社，1994
[38] Xu I. J. Wavelet transform domain filters: a spatially selective noise filteration technique[J] . IEEE IP, 1994,13(6):747-758
[39] 王念旭等．DSP基础与应用系统设计．北京：北京航空航天大学出版社，2001．8
[40] 张雄伟，曹铁勇．DSP芯片的原理与开发应用．北京：电子工业出版社，2000．9
[41] 林湘宁，刘沛，程时杰，徐长发，蔡超．小波分析基础理论及其在电力系统中的应用——第1讲小波变换及其时—频局部化特长．电力系统自动化，1997，21(10)：80-83
[42] 林湘宁，刘沛，程时杰，徐长发．蔡超．小波分析基础理论及其在电力系统中的应用——第2讲信号小波分解与回复的快速算法．电力系统自动化，1997，21(11)：75-79
[43] 林湘宁，刘沛，程时杰，徐长发．小波分析基础理论及其在电力系统中的应用——第3讲应用综述．电力系统自动化，1997，21(12)：79-83
[44] 徐永海，肖湘宁，杨以涵等．小波变换在电能质量分析中的应用．电力系统自动化，1999，23(23)：55-58
[45] 胡铭，陈衍．电能质量及其分析方法综述．电网技术，2000，24(2)：36-38
[46] 任震，黄群古，黄雯莹．多层多分辨分析算法及在电力系统中的应用．电网技术，2002，26(6)：5-13
[47] 陈祥训．采刚小波技术的几种电能质量扰动的测量与分类方法．中国电机工程学报，2002，22(10)：1-6
[48] 李威，王建颐，冉启文，纪延超．一种新的电力系统暂态波形检测方法．电力系统自动化，2003，3：45-48
[49] Mc Granaghan M. Trends in power quality monitoring[J] , IEEE Power Engineering Review, 2001,21(10):3-9
[50] Driesen J, Green T, Belmans R. The development of power quality markets[J] , Power Engineering Society Winter Meeting, 2002,1(1):262-267
[2] Dugan R C, et al. Electrical Power System Quality[M] . New York: McGraw-Hill, 1982.
[3] TC 77 WG6(Secretary) 110-R5, Draft Classification of Electromagnetic Environment, January 1991.
[4] IEEE Standard 1159, IEEE Recommended Practices for Monitoring Electrie Power Quality, New York, 1995.
[5] IEEE Standard 519-1992, IEEE Recommended Practices and Requirements for Harmonic Control in Electrical Power Systems, New York, 1992.
[6] Dugan R C, McGranagban M F, Beaty H W. Electrical Power Systems Quality. New York: MeGraw-Hill, 1996
[7] Warren C M. The Effect of Reducing Momentary Outages on Distribution Reliability Indices. IEEE Trans on Power Delivery, 1993,8(3): 1610—1617
[8] 林海雪．电力系统的三相不平衡．北京：中国电力出版社，1998
[9] Dugan R C. Simulation of Arc Fumace Power Systems. IEEE Trans on Industry Application, 1980, 16 (6): 813—818
[10] 吕润馀．电力系统高次谐波．北京：中国电力出版社，1998
[11] 张一中．电力谐波．成都：成都科技大学出版社，1990
[12] 水利电力部．电力系统谐波管理暂行规定(SD 126-84)．北京：水利电力出版社，1985
[13] 国家技术监督局．电能质量—公用电网谐波(GB／T 14549-93)．北京：标准出版社，1993
[14] 王越，刘晋平，李向荣．用新型静止无功发生器抑制电压闪变之研究．电网技术，1998，22(9)：61-64
[15] 祁碧茹，肖湘宁．IEC闪变仪仿真．华北电力大学学报，2000，27(1)：19-24
[16] 雷林绪．对电压波动闪变仪校验的一点看法．电网技术，1999，23(3)：41-43
[17] 蔡邠．电力系统频率．北京：中国电力出版社，1998
[18] Chui C K. An Introduction to Wavelets. New York: Academic Press, 1992
[19] 胡昌华，张军波，夏军，等．基于MATLAB的系统分析与设计—小波分析．西安：西安电子科技大学出版社，1999
[20] 王世一．数字信号处理．北京：北京理工大学出版社，1997
[21] 李庚银，陈志业，宁宇．快速傅立叶变换的两种改进算法．电力系统自动化，1997，21(12)：37-40
[22] 张伏生，耿中行，葛耀中．电力系统谐波分析的高精度FFT算法．中国电机工程学报，1999，19(3)：63-66
[23] 赵渊，钟岷秀，周念成，等．电力系统谐波分析仪算法研究．华北电力，1999，27(4)：15-17
[24] Gu J C, Yu S L. Removal of DC Offset in Current and Voltage Signals Using a Novel Fourier Filter Algorithm. IEEE Trans on Power Delivery, 2000,15(1):73-79
[25] L．科恩著．时—频分析：理论与应用．白居宪译．西安：西安交通大学出版社，1998．3
[26] Daubechies I. The Wavelet Transform, Time-frequency Localization and Signal Analysis. IEEE Trans on Information Theory, 1990,36(5):961-1005
[27] Heydt G T, Field P S, Liu C C, et al. Application of the Windowed FFT to Electric Power Quality Assessment. IEEE Trans on Power Delivery, 1999,14(4):1411-1416
[28] 程正兴．小波分析算法与应用．西安：西安交通大学出版社，1998
[29] Huang S J, Hsieh C T, Huang C L. Application of Morlet Wavelets to Supervise Power System Disturbances. IEEE Trans on Power Delivery, 1999,14(1):235-241
[30] Brito N S D, Souza B A, Pires F A C. Daubechies Wavelets in Quality of Electrical Power. Proceeding of IEEE ICHQP Ⅷ. Athens(Greece): 1998.511-515
[31] Angrisani L, Daponte P, Apuzzo M D, et al. A Measurement Method Based on the Wavelet Transform for Power Quality Analysis. IEEE Trans on Power Delivery, 1998,13(4):990-998
[32] Gaouda A M, Salama M M A, Sultan M R, et al. Power Quality Detection and Classification Using Wavelet-Multiresolution Signal Decomposition. IEEE Trans on Power Delivery, 1999,14(4):1469-1476
[33] Gaouda A M, Salama M M A, Sultan M R, et al. Application of Multiresolution Signal Decomposition for Monitoring Short-Duration Variations in Distribution Systems. IEEE Trans on Power Delivery, 2000,15(2):478-485
[34] Santoso S, Powers E J, Grady W M. Power Quality Disturbance Data Compression Using Wavelet Transform Methods. IEEE Trans on Power Delivery, 1997,12(3):1250-1255
[35] Littler T B, Morrow D J. Wavelets for the Analysis and Compression of Power System Disturbances. IEEE Trans on Power Delivery, 1999,14(2):358-364
[36] Possion O, Rioual P, Meunier M. New Signal Processing Tools Applied to Power Quality Analysis, IEEE Trans on Power Delivery, 1999,14(2):561-566
[37] 秦前清，杨宗凯．实用小波分析．西安：西安电子科技大学出版社，1994
[38] Xu I. J. Wavelet transform domain filters: a spatially selective noise filteration technique[J] . IEEE IP, 1994,13(6):747-758
[39] 王念旭等．DSP基础与应用系统设计．北京：北京航空航天大学出版社，2001．8
[40] 张雄伟，曹铁勇．DSP芯片的原理与开发应用．北京：电子工业出版社，2000．9
[41] 林湘宁，刘沛，程时杰，徐长发，蔡超．小波分析基础理论及其在电力系统中的应用——第1讲小波变换及其时—频局部化特长．电力系统自动化，1997，21(10)：80-83
[42] 林湘宁，刘沛，程时杰，徐长发．蔡超．小波分析基础理论及其在电力系统中的应用——第2讲信号小波分解与回复的快速算法．电力系统自动化，1997，21(11)：75-79
[43] 林湘宁，刘沛，程时杰，徐长发．小波分析基础理论及其在电力系统中的应用——第3讲应用综述．电力系统自动化，1997，21(12)：79-83
[44] 徐永海，肖湘宁，杨以涵等．小波变换在电能质量分析中的应用．电力系统自动化，1999，23(23)：55-58
[45] 胡铭，陈衍．电能质量及其分析方法综述．电网技术，2000，24(2)：36-38
[46] 任震，黄群古，黄雯莹．多层多分辨分析算法及在电力系统中的应用．电网技术，2002，26(6)：5-13
[47] 陈祥训．采刚小波技术的几种电能质量扰动的测量与分类方法．中国电机工程学报，2002，22(10)：1-6
[48] 李威，王建颐，冉启文，纪延超．一种新的电力系统暂态波形检测方法．电力系统自动化，2003，3：45-48
[49] Mc Granaghan M. Trends in power quality monitoring[J] , IEEE Power Engineering Review, 2001,21(10):3-9
[50] Driesen J, Green T, Belmans R. The development of power quality markets[J] , Power Engineering Society Winter Meeting, 2002,1(1):262-267