A method for transmission loss allocation based on sensitivity theory

This paper presents a methodology for active transmission loss allocation based on AC power flow and sensitivity techniques. Loss factors for active power consumers and suppliers are calculated through the sensitivities of total losses with the increase of active power in each bus and indicate the portion of losses that must be attributed for each market participant for a given scenario. The idea is to allocate the active power transmission losses by means of sensitivity theory, where the loss factors are obtained by an analytic expression obtained from the AC power flow equations. This technique is applied to the Brazilian North-Northwest system composed by 398 buses. An AC incremental method for loss allocation, based on repetitive power flow calculations, is also presented in this paper to provide a comparison basis for the proposed sensitivity methodology. The sensitivity technique showed to be simple and easy to understand and to implement. The loss factors do not depend on the slack bus, as well as the sensitivity methodology provides results close to the ones offered by the repetitive incremental method but, it requires much lower computational effort.