Term Acronym Definition
Fully Autonomous Remedial Actions Optimiser FARAO open-source project aiming at providing an efficient solution for electrical power systems’ Coordinated Capacity Calculation, Local Security Analysis and Coordinated Security Analysis
CAlculation with Scalable and Transparent OptimiseR CASTOR non-costly remedial actions optimiser
Transmission System Operator TSO entity entrusted with transporting energy in the form of natural gas or electrical power on a national or regional level, using fixed infrastructure.
Remedial Action Optimisation RAO provides an optimal selection of remedial actions to handle overloads on network elements (CNECs) in contingency situations (outages)
Individual Grid Model IGM the grid model of a specific TSO
Common Grid Model CGM the “merged” grid models of multiple TSOs into one grid model
Critical Branch CB an important network element with regards to grid security and market exchanges
Critical Outage CO a probable event consisting in the loss of 1 or more elements on the grid. Also refers to a contingency.
Critical Branch - Critical Outage CBCO Critical Branch monitored after a Critical Outage (same as CNEC)
Critical Network Element CNE A monitored Critical Network Element (can be a CB)
Critical Network Element & Contingency CNEC Critical Network Element monitored after a critical Contingency (can be a CBCO)
Contingencies, Remedial Actions and other Constraints CRAC file model containing COs, CNECs, and remedial actions
Phase Shift Transformer PST transformer that can be used to control the power flow on lines
Remedial Action RA action on the network performed to reduce constraints on CNECs
Linear Remedial Action LRA types of remedial actions considered to have a linear effect on flows (e.g. changing the angle of a PST, the set-point of an HVDC, the set-point of a generation unit)
Preventive Remedial Action PRA remedial action performed on the N-state (i.e before any contingency)
Automatic Remedial Action ARA remedial action triggered automatically without any human intervention after a contingency (also called SPS)
Curative Remedial Action CRA remedial action performed by human activation after a contingency
Remaining Available Margin RAM for a CNEC, the remaining flow margin between its actual flow and the maximum flow allowed
Net Transfer Capacity NTC capacity calculation method providing a unique capacity value per frontier by disregarding other bidding zones’ electrical impact
Flow-Based FB capacity calculation method providing a capacity value for each CNEC by taking into account all bidding zones’ electrical impact
Generation and Load Shift Keys GLSK provides net position variation mapping rules to a network’s generators and loads
Power Transfer Distribution Factors PTDF indicates the incremental change in real power that occurs on transmission lines due to real power transfers between two regions
Regional Coordination Center RCC perform tasks of regional relevance in the system operation region (SOR) where they are established, such as, in particular: coordinated capacity calculation, coordinated security analysis and creating common grid models
iTesla Internal Data ModeL IIDM the PowSyBl native grid format (see on PowSyBl)
Union for the Co-ordination of Transmission of Electricity UCTE the UCTE-DEF (UCTE Data Exchange Format) format is an exchange format specified by the UCTE, for the exchange of grid model among its members
Common Grid Model Exchange Specification CGMES an IEC technical specification (TS 61970-600-1, TS 61970-600-2) based on the IEC CIM (Common Information Model) family of standards
Capacity Allocation & Congestion Management CACM methods for calculating how much capacity can market participants use on cross border lines without endangering system security
Regional Security Coordinators RSC evolved into Regional Coordination Centres (RCCs) in July 2022
European Network of Transmission System Operators for Electricity ENTSO-E association for the cooperation of the European transmission system operators (TSOs)
Mixed-Integer Linear Programming MILP optimisation problem in which some of the variables are constrained to be integers, while others are allowed to be non-integers. The objective function is linear with respect to the variables.
Temporary Admissible Transmission Loading TATL admissible load on a CNEC after a contingency in a restricted time frame
Permanent Admissible Transmission Loading PATL admissible load on a CNEC (before or after a contingency) in a steady state
Minimum Margin MM the minimum flow margin among all CNECs
Minimum Relative Margin MRM Minimum Margin (MM) divided by the sum of PTDFs (sum of zone-to-zone PTDFs on the given CNEC)
Common Information Model CIM file format standards developed by ENTSO-E in line with TSO requirements