Identification of transmission line user and congestion management by loop flow controllers

The deregulation of electric power industry has been proceeding in Japan. Some new comers\´ can use traditional power utilities\´ transmission lines under proper rules. In this situation, a question: "Who use individual transmission lines" has become an important concern. Since an organization like ISO or RTO has to manage the congestion and has to charge proper transmission fee to users. The loop flow control by DC-link and phase-shifter (UPFC) is also essential issue. A system operator has to obey proper control rules which should be fair and equal to all related members. In this paper, a simple algorithm has been proposed to identify the transmission users in the third party access. This algorithm is based on "DC-flow" approach, which treats only the injection power (P) and the voltage phase angle (delta). DC-link, phase shifter and switching of CB can control loop flows. Every loop flow controller can be modeled as pseudo power injections at both "from" and "to" nodes of each controller. These injections have same absolute values with opposite sign. The effects of controllers can be identified and isolated independently from other load flows. In this paper, two steps of loop flow control have been discussed. In the first Control-1, a system operator adjusts the loop flow controllers using an optimization method based on LP or QP. These control action does not affect to energy balance in each company. In the second Control-2, a system operator indicates required modifications of line flows to each company so as they can change their energy balance by themselves. Although we could not complete numerical tests in this stage, we check the performance in near future using larger test cases