Introduction: Network unbalance can be an issue for customers and DNOs. It can cause damage to equipment, increase system losses, reduce network capacity, and prevent optimal feeding arrangements. Historically, voltage unbalance occurred due to the connection of single phase loads and conventional corrective action methods involved the permanent reconnection of specific loads to other phases.

The increased in single phase distributed generation is expected to cause a rise in voltage unbalance issues, which will become more noticeable, especially as voltage unbalance on the network can prevent the connection of three phase Distributed Generation (DG). As much of the future DG will be intermittent (Wind, PV, etc.), detecting the source of the voltage unbalance and applying conventional corrective action is also likely to become more difficult.

Objectives: This project aims to determine a method of identifying the source of unbalance on a 33kV mesh network using a minimal number of monitors.