Optimal ATC Allocation in Power Systems

When there are transmission service requests for a specific sink/source pair in a transmission system, the ISO must allocate the ATC of that pair to the requests. Since the requests could have different types, tariffs and time frame, the allocation must be accomplished in a sound and fair manner that considers various aspects of the requests. This paper proposes an approach to allocate the ATC to transmission service requests in both operating and planning horizons. The proposed method considers types and tariffs of requests in a nonlinear optimization which maximizes the expected net revenue of ATC allocation. The solution to the optimization problem gives the amount of accepted requests. The proposed method is applied to a test system and its performance is evaluated through a series of studies.

I. Introduction

Restructured electric power environment has added commercial attributes to transmission services. By definition, a transmission service is called recallable when a transmission provider has the right to interrupt all or part of the service for any reasons, including economics, which are consistent with the transmission provider's transmission service tariffs or contract provisions. For nonrecallable transmission services, the service is to be curtailed only in cases when the system reliability is threatened or emergency conditions exist.