Automatic Three Phase Balancing in Utility Applications

Abstract

Balancing three-phase power has become more important as modern loads like EVs and large agricultural fans create fast and uneven changes in distribution systems. Manual balancing is slow, inconsistent, and often only done during certain “seasons,” which leaves long periods of imbalance. This paper reviews existing automatic methods such as the Fast-Switching Relay method, the Practical Balancing Algorithm, and the Phase-EQ system and highlights their benefits and limitations. Based on this analysis, a new method called the Predicted Practical Balancing Algorithm (PPBA) is proposed. The PPBA combines the stability of threshold-based switching with historical data to predict when imbalances are likely to occur. This allows the system to react sooner while still protecting against unnecessary switching. While the PPBA still depends on having enough good historical data, it provides a more practical and proactive approach for utilities looking to improve phase balancing without major infrastructure changes