Electronics Thermal Management Driven Design of an IP65-Rated Motor Inverter

Authors: Sachin Kamble, Raghothama Anekal, Shivakumar Bhavi

Abstract:

Thermal management of electronic components packaged inside an IP65 rated enclosure is of prime importance in industrial applications. Electrical enclosure protects the multiple board configurations such as inverter, power, controller board components, busbars, and various power dissipating components from harsh environments. Industrial environments often experience relatively warm ambient conditions, and the electronic components housed in the enclosure dissipate heat, due to which the enclosures and the components require thermal management as well as reduction of internal ambient temperatures. Design of Experiments based thermal simulation approach with MOSFET arrangement, Heat sink design, Enclosure Volume, Copper and Aluminum Spreader, Power density, and Printed Circuit Board (PCB) type were considered to optimize air temperature inside the IP65 enclosure to ensure conducive operating temperature for controller board and electronic components through the different modes of heat transfer viz. conduction, natural convection and radiation using Ansys ICEPAK. MOSFET’s with the parallel arrangement, IP65 enclosure molded heat sink with rectangular fins on both enclosures, specific enclosure volume to satisfy the power density, Copper spreader to conduct heat to the enclosure, optimized power density value and selecting Aluminum clad PCB which improves the heat transfer were the contributors towards achieving a conducive operating temperature inside the IP-65 rated Motor Inverter enclosure. A reduction of 52 ℃ was achieved in internal ambient temperature inside the IP65 enclosure between baseline and final design parameters, which met the operative temperature requirements of the electronic components inside the IP-65 rated Motor Inverter.

Keywords: Ansys ICEPAK, Aluminum Clad PCB, IP 65 enclosure, motor inverter, thermal simulation.

References:

[1] https://www.rainfordsolutions.com/ip65-or-ip66-ip-ratings-explained
[2] https://www.inverterdrivesystems.com/what-is-an-inverter/
[3] A. Bar-Cohen, W. M. Rohsenow Thermally Optimum Spacing of Vertical, Natural Convection Cooled, Parallel Plates, in: Journal of Heat Transfer, Vol 106, p. 116-123, 1984
[4] R.K. Rajput, Heat and Mass Transfer, 3rd ed, S.Chand, New Delhi, 2006, pp. 352-372, pp. 495-527
[5] Senapati, J.R., Dash, S.K. and Roy, S., 2016. Numerical investigation of natural convection heat transfer over annular finned horizontal cylinder. International Journal of Heat and Mass Transfer, 96, pp.330- 345
[6] R Simons, Simplified Formula for Estimating Natural Convection Heat Transfer Coefficient on a Flat Plate, in: Electronics Cooling, Issue: August 2001
[7] Stehouwer, H.P. and Hertog, D. den, Simulation-Based Design Optimization: Methodology and Applications, Proceedings of the First ASMO UK / ISSMO Conference on Engineering Design Optimization, Ilkley, UK, 1999.
[8] Parry, J., Bornoff, R., Stehouwer, H.P., Driessen L.T., and Stinstra, E.D., Simulation-Based Design Optimization Methodologies Applied to CFD, Proceedings SEMITHERM XIX, San Jose, 2003, pp. 8-13