| 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 |
