Condition Monitoring of Wind Power Converters Using Heat Flux Sensor
The application of the gradient heat flux sensor as a failure and aging indicator of the power electronics was studied in this paper. Conducted experiments shown that the heat flux sensor attached to the insulated-gate bipolar transistor’s (IGBT’s) base plate can provide real-time heat flux monitoring. Condition monitoring (CM) model implemented in wind turbine based on online comparison of measured IGBT heat flux and expected power losses was proposed. The deviation of the measured heat flux from the expected power losses was detected during IGBT’s package related failures. The maximum deviation of 30% was obtained from the module with broken bond wire. The IGBT's package related degradation mechanisms were modeled by the Finite Element Method (FEM) in order to validate experimental observations. The obtained results have shown that in order to accurately estimate the possible deviation of power losses of the degraded IGBT, the exact change in thermo-electric parameters of IGBT in different failure mechanisms, environmental conditions and operating temperatures should be taken into account.