Over 20 years of experience in power sector! Technical expertise & refurbishing offered to hundreds of large power transformers and primary equipment of 110-750 kV! NOVA INDUSTRIAL S.A. was the official consultant of CNTEE Transelectrica, for the period 2015-2018, in the field of “Power Stations”, for the second consecutive time after the period 2011 – 2014! Our know-how, for your safety !


Equipment for on-line monitoring of power transformers and high voltage shunt ballasts

The NOVA TRAFOMON 5 equipment is intended for online monitoring of power transformers and high voltage shunt ballasts, providing online information on:

  • Operating status: the transformer complies / does not correspond to the operating regulations, it is connected / disconnected to / from the network;
  • Operating conditions: currents, overloads, voltages, voltage increases, frequency, power factor; powers (active, reactive, apparent); temperatures (winding temperature, oil temperature, temperature at the hottest point), energy quality, etc.;
  • Operating status of the active part (core + windings + connections to isolated passages + internal earthing connections) by online monitoring of:
    • Concentrations of gases dissolved in oil: hydrogen (H2), acetylene (C2H2) -optional, a carbon monoxide (CO) -optional, methane (CH4) -optional; ethane (C2H6) -optional, ethylene (C2H4) -optional, carbon dioxide (CO2) – optional, oxygen (O2) – optional, nitrogen (N2) – optional;
    • Partial discharges: acoustic signals produced by partial discharges – optional; or acoustic signals and electrical signals produced by partial discharges – optional;
  • Degree of insulation moisture by: on-line measurement of oil water content and determination of water content in solid insulation;
  • Cooling system operating status:
    • Number of coolers (cooling batteries) in operation;
    • Highlighting the oil pumps and fans in operation, evaluating the cooling efficiency of the coolers, establishing the total operating time or the time between revisions / repairs of the oil pumps and / or the electric fans;
    • Display of the appropriate / unsuitable condition for the cooling system;
  • The insulation state of the insulated high voltage passages provided with the socket for measuring the tangent of the dielectric loss angle, by:
    • Measuring the current through the C1 dielectric, determining the imbalance current resulting from the phasor summation of the currents through the C1 dielectric of the isolated passages mounted on the R, S, T phases of the same three-phase winding;
    • Measuring the capacity of the C1 dielectric at each of the isolated high voltage passages, measuring the tangent of the dielectric loss angle between currents through two isolated passages from the phases of the same winding;
    • Display of appropriate / unsuitable status for high voltage isolated crossings;
  • Operating status of the control switch under load via:
    • Monitoring the operating position of the switch;
    • Measurement of current through the electric drive motor and its footprint;
    • Counting the number of employees;
    • Measuring the temperature difference between the oil temperature in the breaker tank and the oil temperature in the transformer tank (optional);
    • Vibration measurement during operation (optional);
    • Contact status monitoring for: plot switching commands, minimum plot stroke limit signal and maximum plot respectively;
    • Display of the corresponding / unsuitable status for the on-load tap-changer;
  • Condition of the oil conservator corresponding to the main tank: oil level in the conservator, condition of the oil protection membrane against direct contact with the environment (for membrane conservatories) – optional, signaling when reaching the maximum and minimum level, respectively;
  • Condition of the conservator related to the control switch under load: signaling when reaching the maximum and minimum level, respectively;
  • Operating status of the Buchholz relay: signaling stage and trigger stage, respectively;
  • The operating state of the overpressure relay corresponding to the plot switch breaker tank;
  • Operating condition of the overpressure valves corresponding to the main tank of the transformer.

NOVA TRAFOMON 5 can be used independently or in an integrated online monitoring system for primary equipment in high voltage power stations – Smart Grids.