Power Sandwich industrial drive with SiC JFETs

Abstract

This work presents an implementation of a compact and highly efficient 2.2kW industrial drive using the Power Sandwich layered construction, x-dimension (x-dim) passive components and wide-band gap SiC semiconductors (JFETs and diodes). X-dim SMT components that have uniform height and enhanced thermal properties are stacked between planar substrates to achieve high power density and better thermal performance of industrial drive. The use of wide band gap SiC semiconductors results in an industrial drive efficiency increase of around 3% compared to that of Si-based counterpart. It is found that the parasitic coupling between SiC semiconductors and heat sinks significantly deteriorates the JFET's switching performance. The thermal management concept for industrial drive, in which two separate heat sinks minimises the capacitive coupling effect thus exploiting the full potential of fast SiC JFETs is proposed. The layered 3-D construction and lower power loss enabled by SiC semiconductors allows for reduced thermal management effort and consequently increased power density. The 2.2kW SiC-based industrial drive has the power density of 3.8kW/l, system efficiency of 98.4% and operates at the temperatures below 50°C without typical heavy and/or complex heat sinks.