Thermal design of motor drives for high power density and long life in harsh environments

The paper presents a thermal management concept and thermal design of motor drives for high power density and extra-long life in harsh environments. The thermal management concept is based on a modular circuit assembly method which makes it possible to conveniently upgrade the power and manipulate the life of motor drives in low power range (0.37-4kW). EMI filter and DC link of motor drive are designed using the height-standardized passive components (x-dimension components) which enable implementation of modular motor drive with maximized power density. Thermal design and analysis of motor drive are performed with computation fluid dynamics (CFD) simulations. The proposed thermal management concept is experimentally evaluated with a thermal dummy of a 4kW motor drive. The manuscript proves that the 4kW motor drive cooled by natural convection only reaches the power density of 1.75kW/liter with its life approaching 100000 hours.