【作者】 崔丰；

【导师】 杨建宁；

【作者基本信息】 江苏大学 ， 农业电气化与自动化， 2007， 硕士

【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。更多还原

【Abstract】 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.更多还原