On-line diagnostics of power oil transformers MOSAD®–MST

Monitoring system has been designed for an on-line diagnostics of oil transformers at power plant units, including a nuclear power industry. It is based on the MOSAD®-5 components. The system provides a clear information on a progressing transformer defect in its early stage. In the event of a transformer defect or failure, the system records the failure evolution.

System features

  • MOSAD®–MST is an open modular system allowing modify the scope of monitored parameters according to the transformer specifications

Diagnostics parameters monitored by the MOSAD®–MST system

  • gases dissolved in oil and oil moisture by using a proper analyser
  • current, voltage, power
  • changes of capacitance and dissipation factor of a transformer bushing
  • switching and atmospheric overvoltage
  • short-circuit currents
  • partial discharges
  • transformer oil temperature in various points of the transformer include cooling loops
  • tap changer – status and time behaviour of changing
  • status (binary) parameters

System MOSAD®–MST output functions

  • monitoring and storage of values of the directly measured and derived parameters
  • representation of parameters values indicating an actual condition
  • generation of time sequences of the directly measured and derived parameters
  • a hot-spot calculation model
  • a thermal-power balance model with an energy flow check
  • alarms on exceeding pre-set thresholds
  • MOSAD®–MST system self-diagnostics

MOSAD–MSTMonitoring unit MOSAD®–MST

MOSAD–MSTDetail of Monitoring unit MOSAD®–MST

Transformer bushing sensorTransformer bushing sensor