Control centre

Control centre

During operational planning, a coordinated check of the admissibility of the operation of the power system, i.e. an analysis of operational security, is carried out and, if necessary, the planned operation is brought within permissible limits, and at the same time, plans and forecasts are prepared for the operational management phase. The plans and forecasts prepared during operational planning must meet the requirements for operational and supply security, ensure optimal losses, and enable the maximum possible cross-border transmission capacity.

The operational planning of the operation of the power system is followed by a process of real-time operation management, which takes place around the clock and is ensured by three dispatchers on duty at the same time. Real-time control must ensure the safe and reliable operation of the power system in real time. The tasks of shift supervisors and energy system managers are to correct deviations from the planned balancing schedule in real time, ensure high-quality electricity supply to transmission system clients, manage the maintenance, operation and reserve of transmission system equipment, identify and eliminate disrupted and emergency operations, organise cooperation with clients, and inform the control centres of neighbouring system operators and market participants about changes in cross-border transmission capacities.

In order to successfully perform these tasks, a control system (SCADA) is used in the control centre. The control system in use allows monitoring the position, condition and metering data of all approximately 150 substation devices in the transmission system and controlling their operation. Data from partners (e.g. the transmission systems of Latvia, Lithuania, Poland, Finland) and clients (e.g. wind farms, power plants, distribution network undertakings) that are necessary for managing the operation of the power system also reaches this management system.

However, SCADA is only one of the technical tools that must assist the employees of the Elering control centre in ensuring the reliable operation of the Estonian electricity system. In addition, the following IT applications, among other systems, help employees of the Elering’s control centre to cope with their tasks:

• SCADA/EMS – a complex of programs integrated with SCADA that assesses the state of the power system (for example, compliance with the N-1 criterion);
• LFC controller, which is used to trigger aFRR frequency reserves;
• pan-European frequency reserve exchange platforms MARI and PICASSO;
• load forecasting system;
• wind power plant generation forecasting system;
• balance management software (manages cross-border transmission capacities, balancing schedules, and capacity reserve offers and usage);
• system for managing outages and switching of electrical equipment;
• electronic operational logbook;
• a web application for transmitting urgent market messages (UMM);
• network loss forecasting application;
• day-ahead and intraday electricity exchange trading application (through which network losses are bought and sold);
• application for determining the distance to the location of a short circuit;
• remote access applications for direct current connections between Finland and Estonia;
• remote access application for emergency reserve power plants.

The addition of the EstLink 1 and EstLink 2 direct current connections between Estonia and Finland led to important changes in the work of Elering’s control centre. The opening of the market area of the Nordic power exchange in Estonia in 2010 brought with it additional activities in the management of cross-border transmission capacities and enabled the purchase of electricity from the power exchange to cover network losses starting from 2013.   

In 2014, Elering’s emergency reserve power plants were completed near Kiisa. Both power plants can be automatically started and controlled from the Elering control centre via SCADA, and these plants will be used in the event of emergencies in the Estonian electricity system or neighbouring electricity systems.

The biggest change was the connection to the Continental Europe Synchronous Area on 9 February 2025 and thus the implementation of new principles for balancing and controlling the power system in accordance with the agreement on the operation of the Continental Europe Synchronous Area.

Due to the importance of electricity transmission as a vital service, the likelihood of a large-scale power outage in the transmission system must be minimised. Therefore, the most important tools in the control centre are duplicated. Employees involved in real-time management of the operation of the power system must be able to stand in for other employees working on the same shift, if necessary.