摘要
随着电力、电子技术的迅速发展,特别是电炉炼钢、晶闸管整流、电机变频调速以及洗衣机、空调等家电设备的广泛应用,电网谐波问题正变得日益严峻,严重威胁着电力设备的正常使用。寻求高效、快捷的谐波检测方法,为SVG控制系统提供准确可靠的数据,以便准确、及时地补偿和抑制谐波,对提高电网供电质量,减少电力谐波灾害具有重要的指导意义。
本论文研究了电能谐波各参数的测量算法,通过仿真试验研究了小波分析在稳态和暂态谐波检测方面的应用,发现小波变换能够比较精确的分析暂态干扰、暂态谐波失真等电能谐波信号的突变时间、频率成分和幅度,能够准确地将稳态和暂态谐波信号中的基波分离出来。特别是针对目前颇受关注的电网谐波检测技术进行了深入的探讨,介绍了基于瞬时无功功率理论的小波变换算法,仿真试验表明该方法达到了很好的提取谐波及无功电流的效果。
开发了一种新型的电能谐波参数检测系统,此系统采用主从式系统硬件设计,采用MCU+DSP双CPU并行处理技术,配以适当的外围接口电路来完成所要求的各项功能。MCU选用AT89C51,完成对整个系统的控制,主要包括与DSP进行快速的数据交换和人机交换等;DSP选用TI公司的TMS320VC5402,主要完成电压和电流信号的采集及其进行小波分析和其他相关的数学运算,充分发挥其运算能力强的特长。设计了信号的多通道采样保持和转换电路,实现了多路电力信号的同步采样和快速转换,具有很好的实时性。硬件电路设计上采用了锁相环倍频技术,可以实现每周期128点的同步采样。A/D和DSP之间的通信采用DSP的多通道缓冲串口MCBSP,MCU和DSP之间的通信采用DSP的主机接口HPI。设计了MCU和DSP系统软件,采用C和汇编语言进行混合编程,提高了运算速度。重点介绍了基于小波变换的DSP实现,并对各种基于小波变换的DSP实现算法进行了比较,发现利用传统的算法所得的结果精度不高,利用卷积抽样算法所求的多尺度小波分解系数及其重构系数的精度要高些。在CCS中对卷积抽样算法和DSP系统程序进行了仿真和调试,实现了所需功能。
新型电能谐波参数检测系统,数据处理功能强、精度高、实时性好,特别是如果与SVG系统相连后,可实时对电网进行谐波和无功电流的补偿,具有实际使用价值。
With the development of electricity and electric power industry , the power harmonic become more and more important. It is very constructive to get power harmonic parameter in time.
In this paper, It study the power harmonic parameter arithmetic in difference . Through wavelet transform,the break time in the temporary state can be found and the fundamental current is separated from power current in Matlab. It research harmonic measure in particular and introduce the wavelet transform theory based on the instantaneous reative power, the simulation shows that through this method the total harmonic current in power system is achieved.
On the same time, It design a new power harmonic detection system. The system is composed by MCU and DSP, It use chip AT89C51 made by Ateml, Using MCU to controll the system ; It use chip TMS320VC5402 made by TI, Using DSP to collect power data and process them with wavelet transform. It design and realize muticenter sampling and conversion circuit. The communication between A/D and DSP adopt the DSP of MCBSP, the communication between MCU and DSP adopt DSP of HPI. in the wavelet designing. It design MCU and DSP system software, using c and asm to realize power harmonic measure in CCS. It compare two kind of the realization method based on DSP, The convolution algorithm has decreased the error using wavelet transform to decompose and reconstruct the signal, the harmonic and reative current can be computed with the algorithm in CCS. Emulation and debugging having been in progress to the convolution algorithm and DSP system procedure in CCS, the system have realized the required function.
The new system has strong data process ability. It also can be improved easily and get deal with human friendly. Especially if it connect with the SVG, it can give harmonic and reative current to the SVG So it is suitable to domestic market. It is sure to be applied widely.
引文
[1]唐会智,彭建春.基于模糊理论的电能质量综合量化指标研究[J].电网技术.2003,25(12):85-88
[2]方重秋.电力系统谐波的产生、危害及其抑制[J].文教资料.2006,13(5):222-223
[3]王兆安.谐波抑制和无功功率补偿[M].机械工业出版社,1998
[4]安婷婷.城市电网的谐波污染与治理[M].仪器仪表技术.2006,13(5):14-15
[5]Jos Arrillaga Math H J Bollen.Power quality following deregulation[J].Proceedings of the IEEE.2000,88(2):246-261
[6]Daniel J Ward.Power quality and the security of electricity supply[J].Proceedings of the IEEE.2001,89(12):1830-1836
[7]Lzrry GDurante.Prasanta K.Ghosh.Active Power Measurement in Nonsinusoidal Environments.Power System EEE Transactions on.2000,15(3):1142-1147
[8]董泽波.电力谐波对电能质量计量的影响分析[J].铝加工.2001,24(6):51-52
[9]林海雪.电力系统三相不平衡[M].北京:中国电力出版社,1998:10-42
[10]林海雪,孙树勤.电力网中的谐波[M].北京:中国电力出版社,1998
[11]王建,冉启文等.基于小波变换的时变谐波检测[J].电力系统自动化,1998,22(8):52-54
[12]L.Angrisani,P.Daponte,et al.A measurement Method based on The Wavelet Transform for Power Quality Analysis[J].IEEE Trans.On Power Delivery,1998,13(4):990-998
[13]S.Santcco,W.M.Crady,E.J.Powers,J.Lamoree,S.C.Bhatt.Characterization of Distribution Power Quality Events with Fourier and Wavelet Transforms.IEEETrans.On Power Deliver,2000(15),1:247-254
[14]Huang S J,Hsich C T,Huang C L.Application Morlet Wavelet to Power SystemDisturbances[J].IEE Trans on Power Delivery,1999,14(1):235-243
[15]Pillay P,Bhattacharjee A.Application of Wavelets to model Short-term SystemDisturbances[J].IEE Trans on Power Delivery,1996,11(4):2031-2037
[16]Zheng T,Makram E B,Girgis A A.Power System Transient and Harmonic Studies Using Wavelet Transform[J].IEEE Trans on Power Delivery,1999,14(4):1461-1468
[17]Gaouda A M,Salama M M A,Sultan M R,Chikhani A Y.Power Quality Detection and Classification Using Wavelet-Multiresolution Signal Decomposition[J].IEEE Trans on Power Delivery,1999,14(4):1469-1476
[18]Gaouda A M,Salama M M A,Sultan M R,Chikhani A Y.Application of Multiresolution Signal Decomposition for Monitor Short-Duration Variations in Distribution Systems.IEEE Trans on Power Delivery,2000,15(2):478-485
[19]任震.小波分析及其在电力系统中的应用[J].电力系统自动化,1997,21(12):13-17
[20]杨桦.基于小波变换检测谐波的新方法[J].电力系统自动化,1996,21(10):39-41
[21]杨君.一种单相电路谐波及无功电流的检测新方法[J],电工科技学报,1996,(110):42-46
[22]李庚银.d p0坐标系下广义瞬时无功功率定义及其补偿[J].中国电机工程学报,1996,160:176-179
[23]张乃饶.神经网络与模糊控制[M].北京:清华大学出版社,1998
[24]袁曾任.人工神经网络及其应用[M].北京:清华大学出版社,1999
[25]王群.一种基于人工神经网络的谐波测量方法[J].电网技术,1999,23(1):19-23
[26]危韧勇.一种基于人工神经网络的谐波测量方法[J].电网技术,1999,23(1):19-23
[27]周雕维.基于补偿电流最小原理的谐波与无功电流检测方法[J],电工技术学报,1998,130):33-36
[28]Montano.J.C,Lopez.A,Castilla.M,Gutierrez.J.A DSP-based electric power meter.Industrial Electronics,Control,Instrumentation,and Automati-on,1992.Power Electronics and Motion Control,Proceedings of the 1992 International Conference.1992,(3):1562-1567
[29]Gou.J,Xie.B,Enjeti.P.A DSP based real time power quality measurement system Applied Power Electronics Conference and Exposition,1992 Conference Proceedings 1992.Seventh Annual,1992:29930
[30]黄纯,左辰,周有庆.用8位单片机实现电力谐波在线测量[J]湖南大学学报 1997,10
[31]刘芳亮 蒋大林.智能电力参数综合测量仪表的研究与实现[J].仪器仪表学报,2006,6,206-208
[32]杨洪耕.电能质量问题的研究和技术现状[J].电力自动化设备.2003,23(10):1-4
[33]袁世英,曹晖.基于DSP的电压闪变仪的开发[J].继电器.2005,8(3):6-9
[34]杜海兵.刘建宏.电能质量检测系统方案探讨[J].上海电力.2005,3:249-251
[35]余丹,王庆.基于DSP和MCU的新型电能质量监测装置的设计[J].仪表技术.2004, 8(6):4-9
[36]胡广书.数字信号处理-理论、算法与实现[M].北京:清华大学出版社,2002,53-158
[37]蒋冬初,何飞.FFT算法的并行处理研究[J].湖南城市学院学报.2005,14(2):9-15
[38]Xi J T.A new algorithm for improving the accuracy of periodic signalanalysis.IEEE Trans On IM.1996,8:827- 830
[38]Grandke T.Interpolation algorithms for discrete Fourier transforms of weighted signals[J].IEEE Trans on IM.1983,32:350-355
[40]胡昌华,张军波,夏军等 基于MATLAB的系统分析与设计一小波分析[M].西安:西安电子科技大学出版社,2001,1-6
[41]SRINVASANK.Digital measurement of voltage flicker[J].IEEE Transaction on Power Deliverv.1991,6(4):1593-1598 Packet.IEEE Instrumentation and Measurement Technology Conference,2002,1643-1645
[42]夏雪,周林,万蕴杰.小波变换在谐波检测中的应用[J].电测与仪表,2006,(03)
[43]张向程.基于小波变换的电力谐波参数测量方法研究[D].湖南大学,2004
[44]韩松,邱国跃.基于DSP的三相有源滤波器谐波检测研究[J].2003 12,20-21
[45]周霖,李枫,潘娜.DSP算法设计与系统方案[M].国防工业出版社,2004 7,67-68
[46]Chethan Parameswariah,Mickey Cox.Frequency characteristics of wavelets[J].IEEE Transactions on Power Delivery,2002,17(3):800-804
[47]IEEE Group on Monitoring Electric Power Quality.IEEE P1159.2 Recommended practice for the characterization of a power quality event[S].1998.
[48]程璐.基于TMS320C5402芯片DSK平台的电能质量分析的数据采集[D]南京理工大学,20040301
[49]陈丽安.'C5402 DSP自举引导方法的分析与研究[J].电子技术应用,2002,5:65-68
[50]孙延煃.小波分析及其应用[M].北京:机械工业出版社 19-20