Thermal Analysis of a Integrated Power Electronics Module MANE 6980 Nicholas Palumbo 12/05/2012

IGBT In order to determine losses of the integrated power electronics module, the design engineer needs to determine which semiconductor device the module will make use of. The main heat losses associated with this analysis are due to switching and conduction losses of the IGBT. Integrated power modules are used to power three phase AC motor drives. The figure below better depicts the internal of the power electronics module. Switch 1,2,3,4,5, and 6 are in parallel. The IGBT chosen for this application is the Powerex CM1800HCB-34N single IGBTMOD HVIGBT Module, rated for 1800 Amperes and 1700 Volts. The IGBT module consists of one IGBT transistor in a reverse-connected super-fast recovery free- wheel diode. The figure to the right depicts the model chosen for this analysis. IGBT Module IGBT Circuit Diagram

IGBT power losses are divided into three groups: conduction losses, switching losses and blocking losses (which are normally disregarded). Conduction losses deal with a series connection of DC voltage source of the on-state zero current of the collector-emitter voltage and resistance. Switching losses deal with turn-on energy losses in the IGBT taking into account the switch-on energy and the switch-on energy caused by the reverse-recovery of the free-wheeling diode; switching losses in the IGBT are the product of switching energies and the switching frequency. Semiconductor Losses

IGBT Losses

Cold Plate Physical Design Cold plate designs include two main categories based on piping configurations: 1. Series Piping 2. Parallel Piping For this analysis three separate cold plate designs will be looked at to determine the best configuration. Below are the three cold plate designs. Option 1: Series Option 2: Parallel Option 3: Parallel-Series

Pressure Drop Calculations Pressure drop calculations were completed for all cold plate designs. The importance of a pressure drop calculation is based on the overall fluid system characteristics. Pressure drop calculations were completed for each cold plate design. Graphs below are representing pressure drop vs. cold plate piping distance. Option 1: Series 4.96 PSI Option 2: Parallel 2.67 PSI Option 3: Parallel-Series 7.6PSI

ANSYS Pressure Drops ANSYS pressure drops were completed for cold plate option one and two.

Thermal Resistance Network Thermal Resistance Circuit for Cold Plate Option One Thermal Resistance Circuit for Cold Plate Option Two Cold Plate Resistance Breakdown

Temperature Profile of Cold Plates

ANSYS Meshing of Cold Plate Option One

ANSYS Thermal Results of Cold Plate Option One

Meshing of Cold Plate Option Two

ANSYS Thermal Results of Cold Plate Option Two

ANSYS Thermal Results of a Modified Version of Cold Plate Option Two

Conclusion Condition Cold Plate Option One Cold Plate Option Two Cold Plate Option Two Modified Pressure Drop (psi) IGBT Operating Temperature ( o C) Heat Transfer Coefficient (W/m 2 K) Thermal Grease Temperature Change ( o C) Sil Pad Temperature Change ( o C) Al Plate Temperature Change ( o C) Solder Interface Temperature Change ( o C) Corrosion Resistant Steel Pipe Temperature Change ( o C) De-ionized Water Convective Temperature Change ( o C) De-ionized Water Convective Temperature Change w/ Fouling ( o C) Construction DifficultyModerateHighElevated High