Liquid Metal based Cooling for Power Electronics Systems with Inductor Integrated Magnetohydrodynamic Pump (MHD Pump)

This paper proposes and demonstrates a liquid metal-based cooling system for power converters with an inductor integrated magnetohydrodynamic (MHD) pump. The inductor in this case not only functions as the pump for liquid metal but also can be an essential part of typical power converters such as the output inductor of a buck converter. Two prototypes of liquid metal-based cooling systems were designed and built. The first prototype is an MHD pump with an external current source and permanent magnets and to evaluate the effectiveness and power consumption of liquid metal based cooling. The second prototype for the first time integrates the MHD pump into an inductor, which eliminates the need for an external power supply and permanent magnets. Since the inductor is part of the power converter to be cooled, the flow rate can be self-adjusted with the load condition. Simulation and experimental results validate the concept of the inductor integrated liquid metal pump and demonstrate the advantage of the liquid metal cooling system over non-metallic fluid-based liquid cooling systems in terms of power density, cooling efficiency, power consumption, reduction of rotatory components, and lowered acoustic noise.