Design of High-Performance Toroidal DC-link Inductor for Current-Source Inverters

Advances in wide bandgap (WBG) power switches are creating opportunities for significant mass and volume reductions of power electronic inverters by shrinking passive and cooling components. The miniaturization achieved by using WBG devices including their potential for high-temperature operation is highly appealing for a new approach to integrated motor drives (IMDs) that uses current source inverters (CSIs). Since CSIs use an inductor as their dc-link energy storage, a new class of inductors that operate efficiently at high-frequency and high temperatures are needed. The inductors must have low volume and low mass, combined with a low radiated EMI signature. This paper presents a comprehensive design procedure for toroidal inductors intended for use in CSI inverters. The presented method is straightforward to implement and enables rapid optimization of the inductor designs. A calorimetric test was conducted to measure the inductor losses instead of conventional electrical measurements. This calorimetric measurement method is an appealing alternative to other power loss measurement techniques for high-quality-factor inductors operating at high frequencies.