Representation of load imbalances through reactances. Application to working standards

The Unified Power Measurement is used in this paper to obtain three-phase connections of coils and capacitors which produce the same imbalance impacts than the three-phase loads. These equivalent imbalance circuits absorb the same unbalance currents and powers than the three-phase loads in balanced voltage conditions, but they do not absorb or supply active and reactive powers. The elements of the equivalent imbalance circuit of a load have values which are related to the unbalanced power of that load; thus, the equivalent imbalance circuits can be used to build standards of the unbalanced power as well as passive imbalance compensators for electrical installations. The constitution of the above mentioned equivalent imbalance circuits formed by reactive elements and formulation of their elements is described in this paper for three-phase three- and four-wire loads. Finally, an 1000VA unbalanced power working standard was tested as a practical application of those equivalent imbalance circuits.