Two Phase Cooling of Power Electronics Devices

Transcription

1 Two Phase Cooling of Power Electronics Devices

2 More with Less Power Densities Efficiency Reliability Switching Speed Costs

3 Presentation Outline Overview of Current Cooling Methods 2 Phase Cooling Basic Physics Methods Fluid Choices History & Applications Case Study

4 Power Cycling Capability of IGBTs Source: Infineon, Inc.

5 Traditional Cooling Methods Air Cooled Water Cooled Pros Cons Pros Cons Simple system Lower Power Density High Power Density Complex System Low Cost Maintenance of Filters Reduced climate control requirements Maintenance Reliable & Proven Large Volume Air Movement Higher Cost Requires climate controlled installation Poor dielectric

6 Physics Lab An isothermal process is a change of a system, in which the temperature remains constant: ΔT = 0. Latent heat, characteristic amount of energy absorbed or released by a substance during a change in its physical state that occurs without changing its temperature.

7 Common Isothermal Process A home climate control A home climate control system uses the principles of latent heat transfer to heat and cool your home.

8 Phase Transition Cooling Systems Pool Boiling Spray Cooling Heat Pipe Mechanically Pumped Loop Graphics by

9 2 Phase Evaporative Cooling Condenser Accumulator Pump Cold Plate

10 2 Phase Evaporative Cooling

11 Vaporizable Dielectric Fluid vs Water Deionized Water VDF (R134a) Power Density ~ 1 > 1.4X Corrosiveness Susceptible to Galvanic Action with dissimilar metals Dielectric Properties Dependent upon purity High Compatible with wide variety of metals, rubbers, polymers, engineered plastics, and insulating materials Flow Rates *for equivalent heat dissipation rates 6 liters/minute 1 liter/minute

12 Vaporizable Dielectric Fluid vs Water Water VDF (R134a) Reliability Many connections Isothermic; fewer connections; long life pump Device Junction Higher 4x Lower Temperature Installed Cost Higher Lower Maintenance Filters, Deionizing Resin, shaft seals Check coolant level

13 History & Applications

14 Experimental Layout for MV Drive Cooling Cascaded H-Bridge MV VFD Test Cells Cascaded dge est Ce s Instrumentation for Temperature, Flow, and Pressure Simulated Heat Load w/ Resistors 50kW Pump & Condenser Variable Flow Rate

15 Coolant Response to Heat Loads Temp-2 of IGBT CP-1 Temp-1 of IGBT CP-1 (dode (diode pate) plate) Temp-3 of TGBT CP (Deg C) Temperature Temp-4 of IGBT CP-2 Temp-5 of IGBT CP-2 Heat Load (W) Heat Load :02:24 AM 11:09:36 AM 11:16:48 AM 11:24:00 AM 11:31:12 AM 11:38:24 AM Time At 18 kw of heat (max rated) the max cold plate temperature is 44 C At 18 kw of heat (max. rated), the max cold plate temperature is 44 C i.e. dt of 23 C with resistance of 0.01 C/W

16 Coolant Overload Capability Te emperature (D Deg C) Drive#7ColdPltTemp.#1deg.C. #1 deg. C. Drive #7 Cold Plt Temp. #2 deg. C. Drive #7 Cold Plt Temp. #3 deg. C. Drive #7 Cold Plt Temp. #4 deg. C Heat Load (W Watts) 10 Drive #7 Cold Plt Temp. #5 deg. C Total Heat Watts 0 4:13:26 PM 4:16:19 PM 4:19:12 PM 4:22:05 PM 4:24:58 PM 4:27:50 PM 4:30:43 PM 4:33:36 PM 4:36:29 PM Time With the heat load of 25 kw (39% more than rated) the max cold plate temperature With the heat load of 25 kw (39% more than rated), the max cold plate temperature was 52 o C i.e. only 26 o C over ambient. 0

17 Refrigerant 2 Phase Cooling vs Air At 1100 kw power, temperature rise over ambient for R134a cooled system is 35ºC lower than air cooled system

18 Conclusions Advanced 2 Phase Cooling Advantages Higher Power Density Increased Life and Reliability of Power Switching Devices Higher Performance Range Sealed System Allows for Use in Wide Range of Environments Reduced Maintenance

19 Two Phase Cooling of Power Electronics Devices