On the Assessment of Three-Phase Delta Voltages’ Unbalance

Several existing three-phase delta voltages’ unbalance factors, including the "true unbalance factor" (the negative sequence voltage unbalance factor) and its complex form, are considered. New geometric criteria of delta voltages’ balance and unbalance, based on the dealing with delta voltages’ triangles of equal perimeters and different areas are offered. All the unbalance factors are shown in their dependences on one particular phase voltage (and also on one particular delta voltage), separately on the magnitude (for the case of a single-phase magnitude unbalance) and on the initial phase angle value (for the case of a single-phase angle unbalance). Also the fragment of a LabVIEW virtual instrument for the assessment of the negative sequence voltage unbalance factor and the new geometric factors is offered.