Influence of Transformer Calculating Model to the Fairness of Loss Modification

The network loss modification for bidding prices is based on the result of flow calculation, reflecting the change of transmission cost. Meanwhile, it is an important indicator of market fairness. Based on the power distribution theory and the conservation of cost flow, this paper studies the relationship between network loss and transmission cost. It shows that although the network loss remains unchanged, the transmission cost will change when a component uses two different equivalent models. Taking the IEEE 9 bus system for example, the transmission cost is carefully calculated by using ideal transformer model or equivalent circuit model of type ¿ . The study shows that the cost of transmission is smaller when the equivalent circuit model is chosen. Therefore, the equivalent circuit model is conducive to achieve fairness in the flow calculation of the network loss modification.