Probabilistic estimation of voltage unbalance in distribution networks with asymmetrical loads

The paper presents a method for the detection of areas affected by voltage unbalance in distribution networks and presents the results graphically by “Heat Map”. Voltage unbalance causes overheating of equipment, increased losses and general reduction in efficiency of power system equipment and user devices. This results in additional economic costs for both Distribution Network Operators (DNOs) and consumers. This paper uses three-phase full Newton-Raphson load flow method and Monte Carlo simulations to probabilistically estimate the voltage unbalance level at all buses in the network under unbalanced loading conditions. The usage of “Heat map” graphical representation of the results facilitates easy identification of the areas of the network that are affected the most by unbalance. Proposed methodology is demonstrated on a real 24 bus network with actual network parameters.