ELECTRIC TRANSFORMER ASSEMBLY, METHOD FOR DETERMINING A THERMAL STATE OF AN ELECTRIC TRANSFORMER ASSEMBLY, AND DETERMINATION DEVICE

摘要

1. A transformer assembly (100) comprises an electric transformer (10), a temperature sensor system (20), and a computation unit (30) for determining a thermal state of the electric transformer (10). The electric transformer (10) includes a cooling device (40) having at least one liquid coolant channel (41) arranged such as to absorb exhaust heat from the electric transformer (10) by means of a liquid coolant that is passed through the liquid coolant channel (41), a heat spreader (42) in thermal communication with the liquid coolant channel (41) for transferring heat from the liquid coolant to a heat dissipation surface (43) of the heat spreader (42), and an air blower (45) arranged and configured to effect an airstream (46) along the heat dissipation surface (43) of the heat spreader (42). The temperature sensor system (20) includes an entering coolant sensor (21) arranged for measuring an entering coolant temperature of the liquid coolant upstream of the cooling device (40) and for providing an entering coolant temperature signal (S1), a leaving coolant sensor (22) arranged for measuring a leaving coolant temperature of the liquid coolant downstream of the cooling device (40) and for providing a leaving coolant temperature signal (S2), an entering airstream sensor (23) arranged for measuring an entering airstream temperature of the airstream (46) upstream of the heat spreader (42) and providing an entering airstream temperature signal (S3), and a leaving airstream sensor (24) arranged for measuring a leaving airstream temperature of the airstream (46) downstream of the heat spreader and providing a leaving airstream temperature signal (S4). The computation unit (30) is configured to receive the sensor signals (S1, S2, S3, S4) from the temperature sensor system (20), and configured to determine a thermal state of the transformer (10), in particular of the cooling device (40) or parts thereof, by relating the sensor signals (S1, S2, S3, S4) to each other.