Modeling and Circuit Design of a High-Bandwidth Current Sensor Based on a Planar Rogowski Coil

Accurate current measurement is essential for state monitoring and current control in power converter systems. This paper proposes a high-bandwidth current sensor based on a planar Rogowski coil. First, a detailed model of the planar Rogowski coil is developed, and its parasitic parameters are calculated to determine the coil’ s bandwidth. Subsequently, a hybrid integration circuit combining passive and active integrators is designed to extend the upper frequency limit of the active integration circuit. To address the drift errors introduced by non-ideal operational amplifier, a compensation method is introduced to achieve precise current measurement. Finally, simulations of the proposed current sensing circuit are conducted to verify its effectiveness and feasibility.