Cause Analysis and Practice of Three-phase voltage imbalance in Distribution Network

Aiming at the long standing three-phase voltage imbalance of substation bus in normal operation state of distribution network, through the actual operation data and three-phase power flow simulation process, the reasons for the long standing three-phase voltage imbalance are analyzed in depth. The research shows that the imbalanced Capacitance type voltage transformer is connected to the ungrounded distribution network, and the capacity is easy to cause three-phase imbalance under the normal operation state of distribution network. The research results are applied to the analysis of the causes of voltage imbalance in engineering practice. With three-phase power flow and field data, the analysis workload can be minimized, the efficiency can be improved, and the direction for subsequent imbalance management can be provided.