Impact analysis of distributed energy resources in maintaining unbalanced voltage degree and DLMP

The three-phase distribution system is evolving towards a more unbalanced one in terms of load consumption, which is harmful to both the distribution grid and user equipment. In this study, we integrate the voltage imbalance constraints into the three-phase distribution level market. However, the three-phase distribution locational marginal price (DLMP) may inevitably be affected and exhibit differences between phases. The deployment of distributed energy sources (DERs) is driving the distribution system to be more flexible and could help alleviate the imbalances of three-phase voltage and DLMP. First, the coupling relationship between phases is modelled, and three-phase unbalanced voltage constraints are considered by limiting the magnitude difference between phases. Next, the three-phase nonlinear power losses are linearized via the Taylor expansion. Then, a three-phase distribution market model with multiple types of DERs is established. Finally, the proposed model is tested on the IEEE 33-bus system. The simulation results show that the integration of voltage imbalance constraints and DERs can make the voltage profile between phases more balanced and significantly impact the three-phase DLMP.