考虑含多敏感负荷的配电网电压暂降脆弱区域辨识方法研究

随着变频器和继电器等大量敏感负荷的应用,电压暂降问题愈发成为了配电网尤其是敏感负荷占比很高的现代工业配电网亟需解决的动态电能质量问题。为有效评估配电网中易引发电压暂降的薄弱环节与指导电压暂降补偿方案的设计,提出了考虑多个敏感负荷的配电网电压暂降脆弱区域的辨识方法。首先,通过引入母线暂降判定向量与线路暂降关联向量以及相应的判定准则,确定了目标配电网中临界点在各线路上的分布以及各临界点的位置。其次,基于获得的敏感负荷的电压暂降域,得到了考虑交叠效应的配电网电压暂降域层级模型,并由此定义了电压暂降影响度以实现对配电网内电压暂降脆弱区域的量化评估。最后,将所提方法应用于IEEE14母线系统电压暂降脆弱区域辨识,验证了所提方法的可行性与合理性。

Voltage sag vulnerable area identification of a distribution grid with multiple sensitive loads

With the application of a large number of sensitive loads such as frequency converters and electric relays, voltage sag has become an urgent dynamic power quality issue in distribution networks, especially in modern industrial distribution networks with a high proportion of sensitive loads. In order to effectively evaluate the vulnerability of voltage sag in a distribution network and guide the design of a voltage sag compensation scheme, a method for identifying the vulnerable area of voltage sag in distribution network considering multiple sensitive loads is proposed. This paper first introduces the bus sag identification vector, the line sag identification vector and corresponding judgment criteria. Then the distribution of critical points on each line and the location of critical points in the target distribution network are determined. Secondly, based on the obtained voltage sag region of sensitive loads, a hierarchical model of voltage sag domain of the distribution network considering the overlap effect is derived. In addition, the concept of voltage sag influence degree is thus defined to quantitatively evaluate the vulnerable area of voltage sag in a distribution network. Finally, the rationality and feasibility of the proposed method are verified for voltage sag vulnerable area identification of the IEEE14 bus system. This work is supported by Science and Technology Project of State Grid Corporation of China (No. 52153218000B).