Neutral line breakage judgment method based on three-phase voltage unbalance degree

• Main Authors: ZHANG YUE, JI KUIQIAN, LI JIAYUE, GUO HAO, ZHOU HAORAN, QI SHU, CHEN ZHITING
• Format: Patent
• Language: Chinese; English
• Published: 19.02.2021
• Subjects: MEASURING; MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES; PHYSICS; TESTING

The invention discloses a neutral line breaking judgment method based on three-phase voltage unbalance degree. The method is characterized in that in a formula (1) defined in the specification, [epsilon]u2 and [epsilon]u0 respectively represent negative sequence voltage unbalance degree and zero sequence voltage unbalance degree of an electrical load side, D2 and D0 respectively represent the starting threshold value of the negative sequence voltage unbalance degree and the starting threshold value of the zero sequence voltage unbalance degree, if the formula (1) is met, it is judged that theneutral line of a low-voltage power distribution system is broken, and if the formula (1) is not met, it is judged that the neutral line is not broken. The method can be used for the head end of a power supply loop, is easy to install and maintain, and can judge neutral line breakage faults without dead angles. 本发明公开了一种基于三相电压不平衡度的中性线断线判定方法，按以下进行：（1）式中，、分别表示用电负荷侧的负序电压不平衡度与零序电压不平衡度，、分别表示负序电压不平衡度的启动阈值和零序电压不平衡度的启动阈值；若满足式（1），则