Three-Phase Unbalance Improvement for Distribution Systems Based on the Particle Swarm Current Injection Algorithm

Abstract

The aim of this study is to improve the three-phase unbalanced voltage at the secondary side of a distribution transformer. The proposed method involves compensation sources injecting three different single-phase currents into the connected point of a grid. The computations of optimal single-phase currents are performed using the circuit analysis method and particle swarm optimization algorithm. An unbalanced three-phase power distribution system model is constructed, including a transformer Δ–Δ connection, V–V connection, load balance, load unbalance combination, and three single-phase compensation current sources. The results show that the voltage unbalance rate of the electricity user side is improved to less than 1%, and the three-phase total compensation apparent power is approximately 0 VA. In the future, the application of the model as an auxiliary service could be achieved by adding an energy storage system.

Unbalanced Current Identification of Three-Core Power Cables Based on Phase Detection of Magnetic Fields

“…The first cause is unbalanced loads [ 4 ], such as single-phase and two-phase loads, which increase power losses and can even result in damage to electrical equipment [ 5 ]. As a result, current compensation technology has been extensively researched to counteract unbalanced phase currents [ 6 , 7 , 8 ]. The second cause is single-phase grounding faults [ 9 ], which are common in medium-voltage distribution networks [ 10 , 11 , 12 ].…”