Outage Transfer Distribution Factor

OTDF.

Last Updated:  June 19, 2025

Definition by NERC

Source:

In the post-contingency configuration of a system under study, the electric Power Transfer Distribution Factor (PTDF) with one or more system Facilities removed from service (outaged).

Definition by PowerWorld

Source: Sensitivities > Line Outage Distribution Factors > Line Outage Distribution Factors (LODFs)

An OTDF is similar to PTDF, except an OTDF provides a linearized approximation of the post-outage change in flow on a transmission line in response to a transaction between the Seller and the Buyer. The OTDF value is a function of PTDF values and LODF values.

Calculations can be found in the source reference.