Optimal loss allocation of multiple wheeling transactions in a deregulated power system

This paper presents an approach to optimally allocate transmission losses among the utilities involving in multiple wheeling transactions. The algorithm introduces the calculation of loss ratio according to the losses the individual transaction causes the transmission system when that transaction is taken place alone. During multiple wheeling transactions, the generation output resulting from optimal power flow of the intermediate system remains unchanged. Therefore the losses associated with wheeling transactions are accommodated by supplying utilities. The losses minimizing problem for the intermediate utility is computed with an additional constraint of loss ratio when multiple wheeling transactions occur. The loss ratios are able to proportionally allocate losses for every transaction. The proposed algorithm of the optimal loss allocation for multiple wheeling transactions is tested on a modified IEEE 30 bus system. The results from the algorithm are the optimal real power generated from the supplying utilities which includes their share of losses due to the transactions. The optimal results show that the algorithm can find minimum wheeling losses and divide them among supplying utilities when loss ratio is implemented.