【作者】 凌昊；

【导师】 李凤阁； 佟为明；

【作者基本信息】 哈尔滨工业大学 ， 电气工程， 2010， 硕士

【摘要】 电压闪变是衡量电能质量的一个重要指标。随着一些具有冲击性、非线性负荷的用电设备的广泛使用,电压闪变造成的危害愈演愈烈,导致用电设备的受损,威胁电网的安全运行,严重影响了电能质量。本文对电压闪变检测方法进行了理论分析和研究,分析了平方检波法、全波整流检波法、有效值检波法、小波变换同步检波法、Hilbert变换检波法等五种常用的电压闪变检测方法,提出了基于能量算子的电压闪变检测方法并给出了基于能量算子的离散化电压闪变检测的计算公式。利用MATLAB仿真工具,采用平方检波法、Hilbert变换法和能量算子算法对含有单一频率调幅波和含有多频率调幅波信号分别进行了仿真分析,通过对比仿真结果,验证了能量算子算法应用在电压闪变检测的合理性和准确性。详细分析了IEC推荐的闪变仪闪变值的计算方法,并在Simulink环境下搭建仿真框图,进行了仿真验证。在此基础上,提出了对电压闪变信号进行FFT变换的离散化计算闪变值的方法,并给出了该方法的计算步骤。通过仿真计算结果表明,与IEC推荐的闪变仪采用的闪变值计算方法相比,在能量算子算法的基础上基于FFT的计算闪变值的方法不仅对于闪变值的计算更加准确,而且计算过程更加简便。在对电压闪变检测方法和闪变值计算方法进行理论研究的基础上,设计了一套能够检测电网基本电力参数和电压闪变参数、实时检测并存储故障事件、并具有人机接口和网络通信功能的电压闪变检测仪。该检测仪以TI公司的TMS320F2812为核心,并对系统的各个硬件部分进行了详细的阐述。采用模块化程序设计思想,设计了各个模块的软件。最后对本文所设计的电压闪变检测仪进行了测试,结果表明,达到设计要求。更多还原

【Abstract】 Voltage flicker is one of the most important indexs to assess power quality. With the widely used of electrical equipment with the impactive load and non-linear load, voltage flicker caused more and more serious harm. It caused damage to electrical equipment, affected the safe operation of power grid, maked a serious impact on power quality.This paper analyzes of the voltage flicker demodulation methods detailed. Based on the basic principle of several voltage flicker demodulation methods, such as the square demodulation method, full-wave recetifier demodulation method, the RMS demodulation method, wavelet transform demodulation method, Hilbert transform demodulation method, the voltage flicker demodulation method based on energy operator is proposed, and the discretization formula of the method of the voltage flicker demodulation based on energy operator is derived. It is vertified that the energy operator algorithm is applied to voltage flicker measurement feasibility not only with the singel-frequency amplitude flicker signal but also with the multi-frequency amplitude flicker signal by the simulation software of MATLAB.The simulation analysis is proved that the voltage flicker method based on energy operator is accurate and reasonably by comparing with the detection results of square demodulation method and Hilbert transform demodulation method. The method to calculate the flicker severity used by the IEC recommended flicker meter is introduced and simulated in the simulink simulation. In order to get voltage flicker index accurately, based on the analysis of the method to calculate the flcker severity used by the IEC recommended flicker meter, a method based on FFT to calculate the flicker severity is advanced, and the calculating steps of the method is given.Simulation results concluded that the method based on FFT is more simple and convenient by compared with the method used by the IEC recommended flicker meter.Based on the analysis of voltage flicker demodulation method and the method to calculate the flicker severity, a instrument for measurement of voltage flicker with a human machine interface and network communication functions. It can measure basic electrical parameters and voltage flicker parameters, immediately test and store the failure envent. The hardware system of this instrument used TMS320F2812 from TI as the core, and the each hardware component of the system is described in detail. We apply modular program design method to the design of the software of each module in the system.Finally through the experimental test, we verify the feasibility of the voltage flicker measurement method and the flicker value calculation method applied in this paper.更多还原