Tracing active and reactive power between generators and loads using real and imaginary currents

In a competitive environment, usage allocation questions must be answered c learly and unequivocally. To help answer such questions, this paper propose s a method for determining how much of the active and reactive power output of each generator is contributed by each load. This method takes as its st arting point a solved power flow solution. All power injections are transla ted into real and imaginary currents to avoid the problems arising from the non-linear coupling between active and reactive power flows caused by loss es. The method then traces these currents to determine how much current eac h source supplies to each sink. These current contributions can then be tra nslated into contributions to the active and reactive power output of the g enerators. It is also shown that the global contribution of a load can be d ecomposed into contributions from its active and reactive parts. This decom position is reasonably accurate for the reactive power generation. To deter mine the contributions to active power generation, the previously-described method based on the active power flows is recommended.