Purpose and responsibilities
Article 56
1. Each TSO and each transmission-connected DSO or SGU may perform operational testing respectively of its transmission system elements and of their facilities under simulated operational conditions and for a limited period of time. When doing so, they shall provide notification in due time and prior to the test launch and shall minimise the effect on real-time system operation. The operational testing shall aim at providing: (a) proof of compliance with all relevant technical and organisational operational provisions of this Regulation for a new transmission system element at its first entry into operation; (b) proof of compliance with all relevant technical and organisational operational provisions of this Regulation for a new facility of the SGU or of DSO at its first entry into operation; (c) proof of compliance with all relevant technical and organisational operational provisions of this Regulation upon any change of a transmission system element or a facility of the SGU or of the DSO, which is relevant for system operation; (d) assessment of possible negative effects of a failure, short-circuit or other unplanned and unexpected incident in system operation, on the transmission system element, or on the facility of the SGU or of the DSO. 2. The results of the operational testing referred to in paragraph 1 shall be used by a TSO, DSO or a SGU, in order for: (a) the TSO to ensure correct functioning of transmission system elements; (b) the DSO and SGUs to ensure correct functioning of distribution systems and of the SGUs' facilities; (c) the TSO, DSO or SGU to maintain existing and develop new operational practices; (d) the TSO to ensure fulfilment of ancillary services; (e) the TSO, DSO or SGU to acquire information about performance of transmission system elements and facilities of the SGUs and DSOs under any conditions and in compliance with all relevant operational provisions of this Regulation, in terms of: (i) controlled application of frequency or voltage variations aimed at gathering information on transmission system and elements' behaviour; and (ii) tests of operational practices in emergency state and restoration state. 3. Each TSO shall ensure that operational testing does not endanger the operational security of its transmission system. Any operational testing may be postponed or interrupted due to unplanned system conditions, or due to safety of personnel, of the general public, of the plant or apparatus being tested, or of transmission system elements or of the facilities of the DSO or SGU. 4. In the event of degradation of the state of the transmission system in which the operational testing is performed, the TSO of that transmission system shall be entitled to interrupt the operational testing. If conducting a test affects another TSO and its system state is also degraded, the TSO or SGU or DSO conducting the test shall, upon being informed by the TSO concerned, immediately cease the operational test. 5. Each TSO shall ensure that the results of relevant operational tests carried out together with all related analyses are: (a) incorporated into the training and certification process of the employees in charge of real-time operation; (b) used as inputs to the research and development process of ENTSO for Electricity; and (c) used to improve operational practices including also those in emergency and restoration state.