电网畸变信号下电能的计量方法研究

发布时间：2018-02-28 13:24

本文关键词： 畸变信号提升小波变换合理计量电能计量装置　出处：《青岛大学》2017年硕士论文　论文类型：学位论文

【摘要】：现代电网中由于非线性、冲击性负载的出现,造成了非正弦、非稳态畸变信号的产生。由于传统电能计量装置是基于稳态正弦信号的设计,在畸变的情况下传统电表会错误计算电能,给电力公司和用户造成经济损失,并且畸变信号反馈回电网,会对电能质量产生影响。因此,研究合理的电能计量方法、设计合理的计量装置,是具有一定的实用价值。本文研究了提升小波变换算法对畸变信号进行分析和计算,而且设计了基于TMS320F28335的电能计量装置。首先,将电网畸变信号提炼出典型特征,然后进行分类抽象简化处理,建立电网畸变下信号的数学模型,并根据功率潮流方向分析理论,证明传统电能计量方式的不合理性。其次,运用提升小波变换算法对畸变信号进行分析和计算。论述了小波变换分频带测量电能的方法,并通过小波基选择,提高算法的精度,同时以传统畸变和非传统畸变电网两类信号为例,通过Matlab仿真,验证算法的合理性。最后,详细介绍了电能计量装置的软硬件设计。为了保证系统的运算速度和计量精度,本文在硬件电路设计中,选用TMS320F28335硬件系统,完成了畸变信号处理、电能计量的数据处理工作以及液晶显示、数据采集模块控制的工作。同时,在软件设计方面,根据模块化思维,完成了主程序和各功能子程序的设计,并在CCS环境下完成软件的编程和调试工作。
[Abstract]:Because of the nonlinearity and the appearance of impact load in modern power network, non-sinusoidal and unsteady distortion signals are produced. Because the traditional electric energy metering device is based on the design of steady-state sinusoidal signals, Under the condition of distortion, the traditional electric meter will miscalculate the electric energy, cause economic loss to the power company and user, and the feedback network of distortion signal will have an impact on the power quality. It has certain practical value to design a reasonable metering device. In this paper, the lifting wavelet transform algorithm is studied to analyze and calculate the distortion signal, and the electric energy metering device based on TMS320F28335 is designed. Abstract the typical characteristics of power grid distortion signal, then classify and abstract simplify the signal, establish the mathematical model of power grid distortion signal, and according to the power flow direction analysis theory, prove that the traditional power measurement method is not reasonable. The distortion signal is analyzed and calculated by using lifting wavelet transform algorithm. The method of measuring electric energy in sub-band of wavelet transform is discussed, and the accuracy of the algorithm is improved by selecting wavelet basis. At the same time, taking two kinds of signals of traditional distortion and unconventional distortion as examples, the rationality of the algorithm is verified by Matlab simulation. Finally, the software and hardware design of the power metering device is introduced in detail. In the hardware circuit design, TMS320F28335 hardware system is used to complete the data processing of distortion signal, electric energy metering and the control of liquid crystal display and data acquisition module. At the same time, in the aspect of software design, According to the modular thinking, the main program and each function subroutine are designed, and the software programming and debugging are completed in the CCS environment.
【学位授予单位】：青岛大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM933.4

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