Polskie Sieci Elektroenergetyczne S.A. (PSE) together with Slovenská Elektrizačná Prenosová Sústava, a.s. (SEPS), TSOs of Poland and Slovakia, performed on the 14th and 24th of June 2024 restoration tests in Top-Down approach with support from neighboring TSO.

The restoration tests aimed to verify the possibility of efficient and quick implementation of procedures for restoring the power supply to the power system after the blackout (so called black start). Moreover, the tests allowed dispatchers from National and Regional Control Centers to practice procedures related to the system restoration.

The restoration tests were performed according to two separate scenarios. On June 14, 2024, PSE took the role of the supporting operator. A separate area of ​​the Slovak system was supplied by PSE, which enabled the supply of electricity to 14,000 customers connected to the distribution grid but also the activation of auxiliaries of the Košice CHP plant. On June 24, 2024, the Slovak system operator helped to re-power one of the Polish system power plants. It was activated and synchronized with the entire system of continental Europe.

Both restoration tests were completed successfully. All activities were carried out by previously prepared test programs, preceded by detailed analyses. Conclusions developed based on recorded measurements will be included in the update of the restoration procedures in bilateral agreements.

Cooperation with other operators to ensure the reliable operation of interconnected systems is one of the TSO’s obligations under national and European law. It includes the development of restoration plans for Emergency and Blackout accidents. To be prepared to black start the system after a failure, PSE has, among other procedures, bilateral agreements with transmission system operators of neighboring countries, which contain detailed plans and conditions for mutual assistance.