Analytical Assessment of the Network Losses Using Structural Generation Decomposition, Considering the Congestion

The main goal of this paper is to structural and mathematical analysis of the network losses in different load levels. In order to achieve this aim, at the first step, the market is dispatched and the structural generation decomposition is proposed in lemma 1. This analytical decomposition reveals the sensitivity factor of marginal unit's generation to each bus load variation. At second step, in Lemma 2, the analytical relationship between the change of lines flow and load changes has been obtained. Finally the Loss Index for each bus, LIn and the network LIsys analytically is defined, using lemmas 1&2. LIn analytically indicates the variation of network losses by variation of load at bus n. It is expected that the LIn be the positive value. But, according to the market problem, load and generation disperse and congestion LIn may be the negative value, unexpectedly. In this paper, in view point of the losses, the critical load point of each bus and the network is defined as the bus load or the network load value that change the sign of the LIn and LIsys, respectively. Moreover, the critical area of the load in viewpoint of the losses is defined as the load area that leads the maximum network losses. These results can be useful to decision making on the location options of the DSM programs. Finally the three IEEE standard networks are analyzed.