Complete Loss and Thermal Model of Power Semiconductors Including Device Rating Information

Abstract

Thermal loading of power devices are closely related to the reliability performance of the whole converter system. The electrical loading and device rating are both important factors that determine the loss and thermal behaviors of power semiconductor devices. In the existing loss and thermal models, only the electrical loadings are focused and treated as design variables, while the device rating is normally predefined by experience with limited design flexibility. Consequently, a more complete loss and thermal model is proposed in this paper, which takes into account not only the electrical loading but also the device rating as input variables. The quantified correlation between the power loss, thermal impedance, and silicon area of insulated gate bipolar transistor (IGBT) is mathematically established. By this new modeling approach, all factors that have impacts to the loss and thermal profiles of the power devices can accurately be mapped, enabling more design freedom to optimize the efficiency and thermal loading of the power converter. The proposed model can be further improved by experimental tests, and it is well agreed by both circuit and finite element method (FEM) simulation results. Index Terms-Finite element method (FEM), insulated gate bipolar transistor (IGBT), power semiconductor, reliability, thermal model.

A Technique for Mitigating Thermal Stress and Extending Life Cycle of Power Electronic Converters Used for Wind Turbines

“…Switching energy losses for a single power electronics module, over one period of switching processes, are divided into Turn-on and Turn-off losses, ESW,ON and ESW,OFF, for the IGBT. The instantaneous switching power losses, PSW,IGBT of IGBT can be calculated as [27,28]:…”

“…Average switching power losses, PSW,AV, over IGBT and diodes within total number of cycle, N, in each fundamental frequency at n th switching period can be denoted as [2,28]:…”

“…Similar to the derived d-q elements for the three phase line voltages in previous section, stator voltages vsd,q can be expressed as follows [38,39]: (28) where ωd is instantaneous speed of d-q winding set in the air gap, λsd,q and λrd,q are the stator and rotor flux linkage expressions, respectively. vrd,q rotor winding voltages are given as: (30) where ωdA is the instantaneous speed of the d-q winding set in the air gap with respect to the rotor A-axis speed.…”

Application of a Heat Flux Sensor in Wind Power Electronics

“…The latter causes the cyclic thermo-mechanical stress in the module, which induces wear-out mechanisms. The research of the failure mechanisms caused by the reason of different thermal expansion properties is carried out in [3][4][5][6]. However, the structural deformation of the module and the change in thermal parameters of the device result in changed heat conduction properties and the heat flux distribution pattern in the IGBT module.…”

“…The approach based on power loss calculation calls for knowledge of the thermal impedance to achieve the loss/temperature profiles, because the IGBT electrical characteristics are functions of junction temperature [5]. Therefore, the practical implications of this method in a multi-device system are highly complicated because of the excessive use of data and short sample time [13].…”