非线性谐波电能计量技术及其应用

发布时间：2018-09-11 06:04

【摘要】：随着工业现代化的发展,公用电网中的电气化铁路、电力机车等非线性负荷数量在不断增加。然而,由于非线性负荷向电网注入大量的谐波,以致电网电压、电流波形发生畸变。电网谐波不仅会危害供电网络和用电设备,而且影响电能计量的准确度,造成供电企业和线性用户的经济损失。从我国现行的电能计量相关政策以及所使用的电能计量装置来看,在公用电网含有谐波时,对于电能计量装置的影响,谐波电能如何计量等问题还有待解决。因此,设计一种区分基波、谐波的电能计量表计,有助于提高对非线性用户电能使用的监测水平。监测数据可作为谐波源分析的依据,并为谐波电能收费的合理性评估提供数据基础。本论文介绍了电网谐波所带来的危害,主要讨论了非线性负荷影响下的电能计量相关技术,如谐波检测方法、检测装置等方面。文中深入地对快速傅里叶变换算法及其所对应的加窗插值修正算法进行分析,并讨论了一种全新的、很适用于嵌入式硬件实现的修正算法,对谐波分析具有重要的参考价值。本课题完成了谐波电能监测装置开发,硬件采用ADC+AF RM结构,通过16位高精度AD芯片对电压、电流进行采样,再使用具有浮点运算单元的ARM芯片进行傅里叶变换和算法修正,将得到的谐波分析结果通过计算得到基波与谐波电能,最终在液晶屏上显示测量结果。通过硬件装置的实际运行验证了数据采样分析流程,运行状况表明：所讨论的加窗插值算法具有高效性。最后,搭建了非线性电路测试所设计的谐波电能计量表计,将其和0.2%精度的电能质量分析仪所测量数据进行对比实验。通过对基波、各次谐波含量,及其所对应的幅值、频率等信息进行分析结果表明：所设计的谐波电能计量硬件装置的精度具备与对比装置精度(0.2%)相当,符合GB/T14595-93中的A类测量仪表的精度要求。本课题的研究成果如加窗插值算法、电能计量硬件装置,对于谐波电能计量具有重要的参考价值。
[Abstract]:With the development of industrial modernization, the number of nonlinear loads such as electrified railways and electric locomotives in public power network is increasing. However, because the nonlinear load injects a lot of harmonics into the network, the voltage and current waveforms are distorted. Power grid harmonic will not only harm the power supply network and power equipment, but also affect the accuracy of power measurement, resulting in economic losses of power supply enterprises and linear users. According to the related policies of electric energy metering in our country and the electric energy metering devices used, the influence of harmonics on the power metering devices and how to measure the harmonic energy still need to be solved when there are harmonics in the public power grid. Therefore, the design of an electric energy meter to distinguish fundamental and harmonic waves is helpful to improve the monitoring level of power consumption for nonlinear users. The monitoring data can be used as the basis of harmonic source analysis and provide the data basis for the rationality evaluation of harmonic energy charge. In this paper, the harms brought by harmonic in power grid are introduced, and the related technologies of electric energy measurement under the influence of nonlinear load are discussed, such as harmonic detection method, detection device and so on. In this paper, the fast Fourier transform algorithm and its corresponding windowed interpolation correction algorithm are deeply analyzed, and a new correction algorithm is discussed, which is very suitable for embedded hardware implementation. It has important reference value for harmonic analysis. In this paper, the harmonic power monitoring device is developed. The hardware adopts ADC AF RM structure. The voltage and current are sampled by 16-bit high-precision AD chip, and then the ARM chip with floating-point operation unit is used to carry out Fourier transform and algorithm correction. The harmonic analysis results are calculated to get the fundamental wave and harmonic energy, and finally the measurement results are displayed on the liquid crystal screen. The flow of data sampling and analysis is verified by the actual operation of the hardware device. The running results show that the windowed interpolation algorithm discussed in this paper has high efficiency. Finally, the harmonic power meter designed for nonlinear circuit testing is built and compared with the measured data of 0.2% precision power quality analyzer. By analyzing the fundamental wave, harmonic content, amplitude and frequency, the results show that the precision of the hardware device is equivalent to that of the contrast device (0.2%). Meet the precision requirements of class A measuring instruments in GB/T14595-93. The research results of this paper, such as windowed interpolation algorithm, electric energy measurement hardware device, have important reference value for harmonic energy measurement.
【学位授予单位】：广东工业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TM933.4

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