Ultrafast Current Sensors for High-Frequency Power Electronics

Power electronics is undergoing a promising transition, with wide bandgap (WBG) semiconductor power devices enabling high-frequency power electronics systems. These systems have unprecedented performance compared to conventional silicon-based power electronics in terms of power density, efficiency and control bandwidth. In order to monitor and control the wide-bandgap devices, Dr. Babak Parkhideh and his research team in the Electrical and Computer Engineering are developing ultrafast sensors optimized for high-voltage power electronics systems operating beyond 1 MHz.

“We are interested in developing nonintrusive current sensing solutions with very high slew rate and frequency bandwidth characteristics, which is much needed for very-high-frequency power converters.” Dr. Parkhideh said.

Dr. Parkhideh’s team is investigating materials and techniques that respond to the magnetic field produced by the current in a printed circuit board trace. The research addresses the challenges of measurements due to asymmetrical current distribution and the significantly non-uniform magnetic field around the trace at frequencies beyond 1 MHz. The approach is to properly shape and amplify the magnetic field with non-invasive Magnetic field CONcentrators (MCON) and active filtering.

“So far, we have achieved a very promising result of DC-10MHz bandwidth and more than 100 A/μS response for ±20A current; an order of magnitude improvement over the current state-of-the-art solutions,” Dr. Parkhideth said. “We have considered many practical issues including the presence of unwanted electromagnetic noises in fast switching power circuits. We believe we can enhance the performance to 30 MHz.”