Extended Wide-Bandwidth Rogowski Current Sensor With PCB Coil and Electronic Characteristic Shaper

Abstract

Because of their fast switching speeds, current measurements for wide band-gap (WBG) devices have become increasingly challenging. Particularly, the designed current sensor must be nonintrusive and have a small size and a very wide bandwidth. One promising current sensor is the printed-circuit-board (PCB) Rogowski current sensor, whose bandwidth is wide only if parasitic parameters of its measuring coil are minimized prominently. This is presently achieved by reducing the number of turns of the coil, which undesirably will degrade its signal-to-noise ratio. Alternatively, an electronic characteristic shaper proposed in this letter can be used for neutralizing parasitic effects, while performing integration to restore the measured current. Theoretical analyses and experimental results have shown that the resulting Rogowski current sensor does indeed have a wider bandwidth, even without changing its measuring coil.