Increasing the reliability of indices for power quality assessment in distribution networks
Increasing the reliability of indices for power quality assessment in distribution networks
复制标题
提高配电网电能质量评估指标的可靠性
DOI：
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发表时间：
2008
期刊：
影响因子：
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通讯作者：
G. Eberl
中科院分区：
文献类型：
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作者：
J. Meyer;P. Schegner;G. Eberl
目前，电能质量，特别是电压质量对于电力公司、制造商和用户以及监管机构来说变得越来越重要。因此，观察到越来越多的电压质量监测活动，其测量时间持续增加，大大长于一周。根据通用标准（例如IEC 61000-2-x或EN 50160）的电压质量评估通常基于一周的评估间隔，而持续一周以上的测量的处理没有明确规定。此外，测量数据包含大量信息，这些信息没有被实际应用的评估方法以最有效的方式使用。特别是对于公用事业的内部规划目的，中期和长期趋势和变化的知识以及典型的时间依赖性客户行为的信息可能非常有用。本文提出了一种方法，包括中期和长期的变化（如季节性变化）的连续电压质量参数（如谐波）的实际水平的计算。该方法基于统计公差界限，并产生更可靠的值，可以与实际标准给出的限值进行比较或用于进一步分析。本文在介绍了目前常用的电压质量评估方法的基础上，对电压质量参数的变化及其典型原因进行了系统的综述。接下来通过几个例子解释统计学基础。最后根据作者的经验，对该方法的实际应用提出了一些建议。
Nowadays power quality, especially voltage quality becomes more and more important for utilities, manufacturers and customers as well as for the regulatory authorities. Therefore a growing number of voltage quality monitoring campaigns with continuously increasing measurement times, considerably longer than one week, are observed. The assessment of voltage quality according to common standards (e.g. IEC 61000-2-x or EN 50160) is usually based on an evaluation interval of one week while the handling of measurements lasting more than a week is not clearly specified. Furthermore the measurement data contain lots of information that is not used by the actual applied assessment methods in the most efficient way. Especially for internal planning purposes within the utilities the knowledge of medium- and long-term trends and variations as well as information about the typical time-dependent customer behavior can be very useful. The paper presents a method that includes medium- and long- term variations (e.g. seasonal variations) of continuous voltage quality parameters (e.g. harmonics) into the calculation of actual levels. The method is based on statistical tolerance bounds and produces more reliable values that can be compared with limits given by actual standards or used for further analyses. After a description of actual assessment methods the paper gives a systematical overview on the variations of voltage quality parameters and typical reasons for that. Next the statistical basics are explained on several examples. Based on the experiences of the authors finally some recommendations for practical application of the suggested method are given.