Transmission Pricing Incorporating the Impact of System Fault and Renewable Energy Uncertainty on the Transmission Margin

To ensure system reliability against unexpected and sudden disturbances, system operators must secure a portion of the transmission capacity of the power system as transmission reserve, which is not used under normal conditions. However, with the recent increase in renewable energy penetration, a transmission reliability margin has been employed under both conditions of system failures and normal operation conditions due to renewable energy uncertainty. Therefore, in the process of transmission pricing, the degree of use of the transmission facilities due to renewable energy uncertainty and system failures should be examined. This paper proposes transmission pricing using usage and reliability contribution factors, which are computed using the degree of use of the transmission lines over all periods. The probabilistic power flow is applied to consider changes in line flows through the forecasting error of renewable energy sources (RES). The proposed method is tested with an IEEE-5 bus system and an IEEE-24 bus system. The test results demonstrate the effectiveness of the proposed method in reasonably allocating transmission costs to network users, taking into account the reliability contribution due to system failures and renewable energy uncertainty.