Online Junction Temperature Cycle Recording of an IGBT Power Module in a Hybrid Car

Abstract

The accuracy of the lifetime calculation approach of IGBT power modules used in hybrid-electric powertrains suffers greatly from the inaccurate knowledge of application typical load-profiles. To verify the theoretical load-profiles with data from the field this paper presents a concept to record all junction temperature cycles of an IGBT power module during its operation in a test vehicle. For this purpose the IGBT junction temperature is measured with a modified gate driver that determines the temperature sensitive IGBT internal gate resistor by superimposing the negative gate voltage with a high-frequency identification signal. An integrated control unit manages the measurement during the regular switching operation, the exchange of data with the system controller, and the automatic calibration of the sensor system. To calculate and store temperature cycles on a microcontroller an online Rainflow counting algorithm was developed. The special feature of this algorithm is a very accurate extraction of lifetime relevant information with a significantly reduced calculation and storage effort. Until now the recording concept could be realized and tested within a laboratory voltage source inverter. Currently the IGBT driver with integrated junction temperature measurement and the online cycle recording algorithm is integrated in the voltage source inverter of first test vehicles. Such research will provide representative load-profiles to verify and optimize the theoretical load-profiles used in today's lifetime calculation.

A Structural Based Thermal Model Description for Vertical SiC Power MOSFETs under Fault Conditions

“…Active and Passive Electronic Components For silicon based semiconductors, this √ -temperature profile inside the chip is described in [12] and verified, through measurements of a cooling curve of a standard IGBT using the , -method (see [14] for times from 80 s until 500 s in [15]). The same behaviour of can be found in SiC devices, as shown with model B.…”

Quantitative Analysis of Efficiency Improvement of a Propulsion Drive by Using SiC Devices: A Case of Study

“…Power losses in the devices are due to conduction [17] and switching [18] phenomena; they cause an increase of the operating temperature of the devices that, in turn, affects their characteristics [19]. Next subsections model the power losses in Si IGBTs, SiC MOSFETs, and freewheeling diodes when inserted in a three-phase inverter that supplies a propulsion motor and calculate the inverter losses in the supply period sup .…”

“…Likewise for Si IGBT, switching losses of SiC MOSFET are given by (19), where ,on and ,off are the energies lost, respectively, in turning-on and turning-off the transistor, and is the switching frequency.…”

Improved reliability of single-phase PV inverters by limiting the maximum feed-in power

“…The mission profile has been witnessed as one determining factor of the failure in power converters [19], [20], [26], [27]. Thus, a mission profile based lifetime analysis approach [17] is extended in the following section considering both short-term and longterm mission profile effects.…”

“…an analytical based Confin-Mason model [12]- [14], [16]. Among these failure factors, thermal stresses, depending on the mission profile as well as the inverter operating conditions, have been the most observed ones in PV systems (both inverters and capacitors) [17], [20]. Hence, the varying operation conditions due to the intermittent nature of solar energy has been one of the challenges to perform reliability analysis in PV systems.…”