三相电压不平衡对开口三角保护的影响

The Influence of Three-phase Unbalance Voltage on Open-delta Protection

目前大量采用开口三角保护作为10 kV并联电容器成套装置的不平衡保护,本文分析开口三角保护与电源三相不平衡的关系,主要通过对开口三角保护公式的推导计算,表明只有当电容器装置的三相阻抗不平衡时才能产生开口三角保护电压。当三相阻抗不平衡时,三相电压不平衡可能引起开口三角电压放大。

At present, open-delta protection is adopted widely as the unbalance protection of 10 kV shunt capacitor complete set. This paper mainly analyzes the relation between open-delta protection and Three-phase unbalanced power supply. The result, throughout deduced calculation of the opendelta protection formula, shows that open-delta protection voltage occurs only in ease of unbalance of the three-phase impedance and, in this case, unbalance of three-phase voltage may cause Open-del- ta voltage to amplify.