• Energy Research
• 2021-2025close

IEEE Transactions on Power Systems, 39 (3) ISSN:0885-8950 ISSN:1558-0679

Phase balancing of American-type three-phase distribution circuits is one of the classical problems faced by distribution system operators and planners. In this paper, a mixed-integer non-linear programming problem is formulated to minimize the number of phase connection changes in existing circuits to reach the desired phase balancing. The proposed algorithm uses geographical information system models of distribution circuits to build a reduced model and realistic load profiles offered by smart meters, or measurements at the distribution transformers to characterize the demand. The formulation is validated in highly unbalanced distribution circuits with thousands of single-phase customers. The results show that it is possible to rebalance large-scale circuits by moving a few single-phase laterals and loads. In addition, the application of the proposed method, based on loading conditions at different hours of the day, pointed out the same places to make the changes.

In the residential sector, electric water heaters are appliances with a relatively high power consumption and a significant thermal inertia, which is particularly suitable for Demand Response schemes. The success of efficient DR schemes via the control of water heaters presupposes an accurate estimate of their power demand at each instant. Although the load of water heaters is rarely directly measured, a large penetration of Smart Meters (SMs) in distribution grids enables to indirectly infer this information on a large scale via load disaggregation. For that purpose, a considerable number of Non-Intrusive Load Monitoring (NILM) approaches are suggested in the literature. However, they require data streams at a time resolution in the range of one second or higher, which is not realistic for standard SMs. Hence, this paper proposes an unsupervised approach to detect and disaggregate the load profile of water heaters from standard SM data with a time resolution in the minute range. Evaluated on multiple real loads with sub-metering, the proposed approach achieves a Normalized Mean Absolute Error (NMAE) lower than 2% and a precision generally higher than 92% with time resolutions between 5 and 15 minutes. 6 pages, 5 figures, published in the Proceedings of the 2020 Mediterranean Conference on Power Generation, Transmission, Distribution and Energy Conversion (MEDPOWER 2020)