According to Article 3(2)(38) of the Network Code on System Operation, 'Restoration State' means the system state in which the objective of all activities in transmission system is to re-establish the system operation and maintain operational security after a blackout state or the emergency state.
Article 18(5) of the Network Code on System Operation
A transmission system shall be in the restoration state when a TSO, being in the emergency or blackout state, has started to activate measures of its restoration plan.
Besides the restoration, blackout and emergency, other system states are:
- normal state,
- alert state.
The criteria to be used by the Transmission System Operator (TSO) when classifying the system state of its transmission system as restoration are as follows:
ii. demand facilities are connected at a pace decided by the TSOs in charge of restoration, depending on the technical capability and feasibility of the transmission system resources and significant grid users (SGUs) which are power generating facilities.
According to Article 18(5) of the Network Code on System Operation a transmission system is considered to be in the restoration state when a TSO, being in the emergency or blackout state, has started to activate measures of its restoration plan.
According to Article 40 of the Emergency and Restoration Network Code (NC ER) each TSO, when in the restoration state, is entitled to gather the following information:
(a) from Distribution System Operators (DSOs) the necessary information about at least:
(i) the part of their network that is in island operation;
(ii) the ability to synchronise parts of their network that is in island operation; and
(iii) the capability to start island operation;
(i) the current status of the installation;
(ii) the operational limits;
(iii) the full activation time and the time to increase generation; and
(iv) the time critical processes.
Network Code on System Operation, Article 3(2)(38), Article 18(5)
Emergency and Restoration Network Code (NC ER), Article 40