Performance evaluation of unbalance sharing responsibility procedures

Three-phase electrical power systems are aimed at providing three sinusoidal voltages with the same magnitude and phase angle displaced in 120° from each other. However, in real installations, the voltages and currents, as a rule, present deviations in relation to the ideal conditions, characterizing a phenomenon classically known as unbalance. This electrical disturbance can occur due to a several reasons and may represent a combination effect of non-ideal conditions found in practical power utilities and consumers. As the power quality indicator herein focused may cause large effects upon electrical system components operation it must be stressed that, in case of regulatory limits are exceeded, mitigating strategies must to be applied. Thus, due to the high costs involving practical solutions, the seek for procedures capable of assigning the sharing of the responsibility between the agents emerges as an imperative requirement. The literature presents several methodologies linked to the sharing of responsibilities regarding the propagation of such disorders, which still need further investigation. In this context, this work is focused on the presentation of the main procedures for sharing responsibility of unbalances present at the point of common coupling between the suppliers and consumer agents, in order to evaluate the effectiveness of the methodologies for different operating conditions associated with the source of unbalance imposed by suppliers and consumers.