【作者】 罗述俊；

【导师】 贺建闽；

【作者基本信息】 西南交通大学 ， 电力系统及其自动化， 2008， 硕士

【摘要】 我国电能质量国家标准主要规定了五个指标—频率、谐波、电压偏差、电压三相不平衡及电压波动与闪变。近年来,依托电力电子技术发展起来的用电负荷日益增多,由于它们非线性、冲击性及不平衡的用电特性,造成诸多电能质量问题,电压波动与闪变就是其中之一。抑制电压波动与闪变,改善电能质量,必须首先对其进行准确测量和有效监视。但与频率、谐波、电压偏差、电压三相不平衡等电能质量问题相比,电压波动与闪变的检测较为复杂,研究相对不足,测量设备较少,因此,本文选择这一问题进行进一步研究。闪变作为评定电能质量的重要指标,能更直接、更迅速地反映出电网的供电质量。在国内还没有很好的电压波动与闪变的数字处理方法,为此论文介绍了电压波动和闪变的基本概念、特征量,从电压波动信号的提取和闪变值的获得两方面系统地阐述了电压波动与闪变的检测原理,分析比较了现有测量方法和装置的特点和优劣。本文的一项重要工作就是依据IEC标准和电压波动与闪变国家标准,在对电压波动与闪变仿真的基础上研究电压波动与闪变测量的数字化实现方法,并对于闪变的评价指标短时间闪变严重度—P_st,分析了三种计算方法。通过Matlab语言对其进行仿真研究,结果表明所提方法能很好满足IEC所提的精度要求,验证了该方法的可行性和有效性,并在LABVIEW环境下设计出数字式闪变仪。更多还原

【Abstract】 Five items, with frequency, harmonics, voltage deviation and voltage fluctuation and flicker respectively, are included in the state standards of energy quality. With the development of power electronic technology, much nonlinear, impactive and imbalance load emerges in power system. As a result, power quality has deteriorated. The problem of voltage fluctuation and flicker, one issue of power quality, becomes more and more serious. To solve the problem and improve power quality, effective supervision and exact measurement is primary. However, compared with frequency, harmonics, voltage deviation, unbalance of three phases, voltage fluctuation and flicker are more complex to be detected, its research is relative to scarce, and the measuring devices are much less. Hence, some further research on measuring voltage fluctuation and flicker has been done in the paper.As an important index to assess the energy quality, voltage flicker reflects the power supply quality more directly and quickly. The basic concepts and character values of voltage fluctuation and flicker are introduced firstly, and then the common methods of suppress the voltage fluctuation are discussed. Further more, the process of extracting voltage fluctuation signal and calculating flicker values is analyzed, and the principle of detecting voltage fluctuation and flicker is detailed. The analog system of the IEC flicker meter is simulated. Then the algorithm of digital system is studied and the digital design result is presented subsequently. In the paper three methods of calculating Short term flicker severity—P_st that is the flicker evaluation index are discussed. The result proved that the algorithm and method presented to be correct and acceptable. This makes it possible to continue the supervisory and measuring device.更多还原