Tie Lines
Tie lines connect balancing authorities and transmission zones across an electric system. PJM relies on accurate tie-line modeling and data collection to perform critical operational calculations and market settlements.
PJM recognizes two types of tie lines for its operations and market settlements: External Tie Lines and Internal Tie Lines.
External Tie Lines
External Tie Lines connect the territory PJM operates to an adjacent grid operator. These ties are included directly into PJM’s Area Control Error calculations.
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.
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