Complex power flow tracing considering convection lines using nominal-T model

The changing structure of the electric power industry is bringing wheeling costing into a new focus. In a competitive market environment, deregulation of the electricity industry and transmission open access make it even more important to fairly allocate the cost of transmission service. Consequently, the power tracing which determines the contributions of individual generators to individual line flows and individual loads becomes more and more important. The proposed method can deal with the problem of reactive power decomposition without any restrictions, even convection lines are considered. Moreover, the proposed method provides possible allocation of line loss to individual generators or loads. An equivalent nominal-T line model replacing the nominal-π model for reactive power decomposition is presented as well. The Graph technique and Proportional Sharing principle are employed for determination of power-tracing sequence and power decomposition. Active power contribution of generators to lines and loads as well as reactive power contribution of generators and lines to loads are calculated. To demonstrate the effectiveness of the proposed method, an IEEE 30-bus system is applied.