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A novel simple method is suggested in this paper to evaluate the contributions of the sources (including the generators and branches’ charging capacitances) or the loads to the branches’ reactive flows and losses separately as well as to calculate the sources’ shares in providing the loads’ reactive powers. In the method, the study system is first converted to the system, each branch of which only has reactive loss, using a new technique for modeling the generating branches based on the AC load flow results. The properties of two new matrices (i.e. injection-bus and absorption-bus matrices), which are constituted for the obtained system, are then used to derive three other matrices. These matrices, which express reactive power productions of the sources in terms of reactive power consumptions of the demands (viz. the loads and branches’ losses) and vice versa, contain the intended contributory factors. Three-bus system is applied to demonstrate the computing process of the method whereas several IEEE systems are used to show its capability to implement on the transmission systems with arbitrary topologies and sizes. Some advantages of the method compared to the earlier methods are also illustrated. [ABSTRACT FROM AUTHOR]

In a deregulated electric power system, it is important to distribute transmission losses between market participants fairly. This paper presents an effective method for active loss allocation by tracing power flow. In this method, after obtaining the alternating current (AC) load flow results of the system, it is first converted to a system in which the power flow is constant along each branch. A new matrix (i.e., power adjacency matrix) is then constructed for the system. The matrix is decoupled, and matrix operations are carried out using the submatrices to derive three other matrices. The contributions of the generators and loads of the main system to active losses of its branches and the shares of the generators in active power consumption of the loads are specified using these matrices. The proposed method is implemented on a four-bus system and several standard test systems. The results show that the method can be applied to any transmission system, and the loss allocation results are preferable to that of previous methods. [ABSTRACT FROM AUTHOR]