Structure and modelling of four‐layer screen‐returned PCB Rogowski coil with very few turns for high‐bandwidth SiC current measurement

Abstract

Accurate measurement of current through a silicon carbide (SiC) device is especially challenging, because of its fast switching speed. Its accompanied current sensor must hence have a high-bandwidth and a high-noise immunity. It must also not interfere with operation of the device. Due to these, the printed-circuit-board (PCB) Rogowski current sensor is particularly suitable, but normally requires many layers. With only four layers, the existing Rogowski coils are not yet capable of shielding ambient voltage and magnetic noises simultaneously. Moreover, their computed and measured self-inductances are usually very different with errors as high as 45% reported in the literature. To resolve these issues, an alternative four-layer screen-returned PCB coil has been presented. The described coil uses very few turns to preserve its high bandwidth at the expense of even tougher determination of its self-inductance. An alternative piecewise modelling method has therefore been proposed for finding its self-inductance, needed for designing its theoretical bandwidth. These, together with a non-inverting integrator, permit current through an SiC device to be measured accurately, as demonstrated experimentally.

A Review of Traditional Helical to Recent Miniaturized Printed Circuit Board Rogowski Coils for Power-Electronic Applications

“…8(a), and hence has a large parasitic capacitance and a small bandwidth. A cheaper and less complex alternative has then been tested in [31] using a four-layer PCB, as demonstrated in Fig. 8(b).…”

“…26(a). This is followed by [31], where the small PCB Rogowski coil in Fig. 26(b) has been used instead with the SiC MOSFET.…”

FEM Analysis and Sensor-Based Measurement Scheme of Current Distribution for Grounding Electrode

“…Therefore, this paper proposes a measurement scheme based on a "drainage wire" with a Hall sensor to capture and measure the weak current in the soil near the grounding electrode. We select a copper drain rod as the current carrier in soil, which can drain the current in soil by laying the "drainage wire" in the soil [22][23][24].…”

Integrated Rogowski Coil Sensor for Press-Pack Insulated Gate Bipolar Transistor Chips

“…The bandwidth is from hundreds Hz to tens of MHz, solving the problem of low sensitivity of passive RC integration [22]. From 2018 to the present, many researcher studied the multilayer PCB Rogowski coil for the measurement of precise impulse current and lightning current [23][24][25][26][27]. However, these coils are circular and can only measure precise impulse current and lightning current.…”

“…The mutual inductance values of a square coil are larger than a circular coil with the same number of turns and cross-section area, which shows that square mutual inductance has more advantages. Moreover, to measure the multi-chip currents in the IGBT, a 4-coil integrated PCB Rogowski coil sensor is designed in this paper, but the coils in [23][24][25][26][27] are a single coil.…”