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Last week saw the arrival in Estonia and initial installation of key equipment required for the Püssi synchronous compensator, providing additional assurance that the first of the three such compensators being constructed for the country will be completed on schedule despite the complicated situation on the global market.

Taavi Veskimägi, the Chairman of the Management Board of Elering, says the synchronisation project has reached a significant milestone. “The compensators are of critical importance in desynchronising from the Russian network and joining the frequency band of Continental Europe,” he explained. “The completion of the compensator in Püssi will be a major step forward in our ability to maintain the stability of our electricity system after disconnecting from the Russian network.”

The equipment delivered for the construction of the synchronous compensator include a flywheel, a transformer and the compensator itself. These pieces of equipment were subject to the longest delivery times, with their design and production having been launched in Q2 2021. Initial installation will be followed by the assembly and configuration of smaller pieces of equipment, acceptance tests and trial operations, which are planned for Q4 2022 and Q1 2023.

Siemens Energy is constructing three synchronous compensators for Estonia: one each for the Püssi, Kiisa and Viru substations. Construction work in Kiisa is set to begin this summer, while the final compensator at the Viru substation is due for completion by the end of 2024.

The synchronous compensators represent an important addition to the electricity system, as they will enable the operator to maintain stability of frequency – the key parameter of any such system – even in critical circumstances. Acute fluctuations in production and consumption are unavoidable in electricity systems, during which extra effort must be made to maintain frequency. A synchronous compensator is a piece of equipment which limits fluctuations in frequency. It does not operate continuously, but is switched on as a preventive measure when needed.