Tie Lines

A tie line is a circuit that connects two or more balancing authorities or transmission zones of an electric system. Being able to accurately model and gather data for tie lines is crucial to PJM’s operational calculations as well as market settlements.

PJM recognizes two types of tie lines for its operational and market settlement purposes: External Tie Lines and Internal Tie Lines.

External Tie Lines

External Tie Lines are ties that connect the territory PJM operates to an adjacent grid operator. These ties are included directly into PJM’s Area Control Error calculations.

Submit Agreements for New or Existing Tie Lines

Internal Tie Lines

Internal Tie Lines connect transmission zones within the region PJM serves. While Internal Tie Lines do not directly affect PJM’s Area Control Error calculations, they have a significant impact on PJM’s internal modeling and Automatic Generation Control calculations, as well as market settlements.

Submit Agreements for New or Existing Tie Lines

Related Manuals

Manual 1: Control Center & Data Exchange Requirements
Section 5.3.5 WEB | Current | Redline PDF

Manual 3A: Energy Management System Model Updates & Quality Assurance
Section 4.4 WEB | Current | Redline PDF