Technical limitations in the transmission network

According to European Union Regulation Nr.714/2009 Transmission system operator (TSO) is required to publish “A general scheme for the calculation of the total transfer capacity and the transmission reliability margin based upon the electrical and physical features of the network”.

Cross-border transfer capacities are calculated following:

  • Total Transfer Capacity (TTC) between Latvian and neighbouring transmission network is calculated for 330kV transmission network, considering power supply reliability securing criterion;
  • Transmission Reliability Margin (TRM) is required for emergency reserve transfers between neighbouring TSO`s during unexpected frequency deviations or network element outages;
  • Net Transfer Capacity (NTC) is result, then TRM is subtracted from TTC.

Cross-border transfer capacities are calculated considering 330kV transmission network electrical and technical parameters: the power transmission line length, the nominal current values, the resistance of power lines, etc. Transmission network modes and interconnection cross-border capacities are calculated with PSS/E software, taking into account EU Regulation Nr.714/2009 principles of transparency and confidentiality.

Latvian TSO “Augstsprieguma Tikls” AS has calculated 330kV transmission network total, net and available transfer capacities, taking into account characteristics and technical limitations in transmission network.