Method of monitoring an electrical machine

A computer program comprising computer code which when executed by processing circuitry of a monitoring device causes the monitoring device to perform the method of:

• a) obtaining temperature measurement values of the temperature at a plurality of locations of the electrical machine,
• b) obtaining estimated temperatures at said plurality of locations given by a thermal model of the electrical machine, the thermal model including initial weight parameter values,
• c) minimizing a difference between the temperature measurement values and the estimated temperatures by finding optimal weight parameter values,
• d) storing the initial weight parameter values to thereby obtain a storage of used weight parameter values and updating the optimal weight parameter values as new initial weight parameter values, and
• repeating steps a)-d) over and over during operation of the electrical machine.

A monitoring device 9 for monitoring an electrical machine, the monitoring device comprises:

• a storage medium comprising computer code, and
• processing circuitry,
• wherein when the processing circuitry executes the computer code, the monitoring device is configured to:
• a) obtain temperature measurement values of the temperature at a plurality of locations of the electrical machine,
• b) obtain estimated temperatures at said plurality of locations given by a thermal model of the electrical machine, the thermal model including initial weight parameter values,
• c) minimize a difference between the temperature measurement values and the estimated temperatures by finding optimal weight parameter values,
• d) store the initial weight parameter values to thereby obtain a storage of used weight parameter values, and updating the optimal weight parameter values as new initial weight parameter values, and
• repeat steps a)-d) over and over during operation of the electrical machine.