Determination of the branch power and loss caused by node injection power

Current methods to determine branch power and loss changes include the DC method, the boundary power flow method and the sensitivity method, however, none of these methods are theoretically correct. Within the framework of an AC power-flow solution the node generation power and node load power are modelled using either a constant impedance or a current source, respectively after being connected to the relevant node. By solving the network current equation, the node voltage can be expressed as a function of the node load power. Similarly, the node voltage can be expressed as a function of the node generation power. Also, the branch power flow and loss caused by the node generation power or the node load power can be obtained by using the proposed expression for the nonlinear function. The branch power loss is allocated to the node power. An example is presented to validate the proposed approach.