A New Fuzzy-Based Representative Quality Power Factor for Unbalanced Three-Phase Systems With Nonsinusoidal Situations

Under ideal sinusoidal operating conditions, the definition of power factor for single-phase and balanced three-phase systems is unique and meaningful. However, in nonsinusoidal situations and/or unbalanced three-phase system operation, different power factors have been proposed to deal with these situations. In this paper, a new fuzzy-based representative quality power factor (RQPF) is introduced to represent three recommended power factors: 1) fundamental positive-sequence power factor (FPSPF); 2) transmission efficiency power factor (TEPF); and 3) oscillation power factor (OSCPF). In addition, the problem of defining power factor for the three-phase system is formulated and the RQPF module is explained. In order to test the validity of the proposed fuzzy-based module, the RQPF is applied to different cases: balanced, unbalanced, linear, nonlinear, sinusoidal, and nonsinusoidal. The results obtained reveal that the new RQPF is meaningful and accurately represents the existing power factors in all cases and in all situations. Taking into consideration the advantages of fuzzy systems, this factor is useful for power quality evaluation, cost-effective analysis of PQ mitigation techniques, as well as billing purposes in these situations.