Merchant power flow controllers

The transmission system in the U.S. is under stress, leading to high congestion costs. To address this issue, more efficient utilization of the existing network is a paramount alternative to building new transmission lines. Significant transfer capability enhancement can be readily achieved via a number of mature technologies that enable power flow control. Despite the promise of power flow controllers (PFC), their deployment has been very limited, due to a number of reasons, including heavy economic regulation. This has many drawbacks, including lengthy planning and approval time, lack of incentives for efficient planning and operation, and transfer of the investment risks to the ratepayers. This paper argues that PFCs pose characteristics that fit well within the framework of merchant transmission without its drawbacks, such as lumpy investments. This paper, thus, proposes to assign financial transmission rights (FTR) to merchant PFC owners based on the additional transfer capability that they offer to the system. The owners are expected to recover their investment costs through the revenues they collect from such FTRs. Unlike regulated rate of return payment, the proposed model provides the right incentive for efficient planning and operation of PFCs. The paper also proves FTR revenue adequacy in presence of the PFCs by developing a simultaneous feasibility test model. The performance of the method as well as its revenue adequacy are demonstrated, first, on a two-bus system, and then, on a three-bus system in presence of loop flows. The paper concludes that opening the electricity markets to merchant PFC projects would reveal profitable investment opportunities to improve the efficiency of the system.