Real Power Loss Allocation for Transactions in Bilateral Markets

The context of transmission loss allocation raised and debated under restructuring of electric supply industry. It is normally defined as a procedure of allocating or charging all participants for their transmission real power loss. In a traditional theory of electricity spot pricing contribution of transmission loss to inject/withdrawal power at each bus is aggregated in a nodal price as an incremental transmission loss. This term is definitely depended on choice of a slack bus thereby charging based on nodal price is a discrimination even a slack bus is specified beforehand with agreement of all participants. The impact of a slack bus, however, has less affect for allocating loss based on transactions with a specified source and sink under bilateral/multilateral markets. In this paper, the authors proposed methodology for allocating transmission loss to bilateral/multilateral contracts in advance for dispatching in real-time. It is formulated based on a slack bus independent concept associated with a fine tuned algorithm to increase calculation speed. Network topology and system condition are taken into account. The proposed method is tested with a 6-bus an IEEE 30-bus systems, from which the results obtained from the IEEE 30-bus system are compared with the one obtained from a pro-rata method. Promising results are obtained and shown that, for transaction of bilateral/multilateral contracts, the proposed method is more sensible than the pro-rata method.