As mentioned above, the modern trend towards improving energy quality indicators necessitates the automation of the MV network. In underground MV networks, automation includes:

  • MV switchgear remote control
  • Remote monitoring of installed equipment (load switches, underground cables, metering equipment, safety equipment).

 Appropriate Remote Terminal Units (RTUs) are used for the above operations. RTUs are installed on MV/HV Substations and are suitable for:

  • Remote control of the installed load switches by the appropriate Network Management Center with simultaneous monitoring of their condition
  • Monitoring the condition of other Substation equipment
  • Short Circuit Current Recognition (fault passage indicator mode)
  • Receiving power measurements from underground cable lines and transmitting them to the appropriate control center
  • Receiving voltage measurements
  • Communication between RTU for automated execution of operations to isolate a fault in the underground network or in combination with a DMS (Distribution Management System) for reorganizing the network in order to reduce technical loss without causing a nuisance to network users.

 Due to their multiple capabilities, the installation of Remote Control Units is useful because it:

  • Reduces the necessary time for repowering customers after an outage or scheduled work which results in improving the performance indicators in supplying electricity to network users (SAIDI, SAIFI, etc.)
  • Carries out network redeployments (supplying network users from a different point in the network in order to reduce their technical losses and strain on their components (conductors, switches, etc.)

 The usual results of the above are as follows:

  • Compliance with the rules set by the Regulatory Authority for Energy (Regulatory Decision)
  • Reduced cost of Undistributed Energy. The cost of Non-Distributed Energy is the cost incurred in the National Economy [€/kWh] for each kWh demanded by consumption which cannot be disposed by the Network
  • Reduced amount of investment to improve the Network.

HEDNO is carrying out the installation of a significant number of Remote Control Units in MV/HV Substations after conducting a study in order to identify the Substations in which installing these units will have the optimal technical and economical result.