A wideband, sensitive current sensor employing transimpedance amplifier as interface to Rogowski coil

In this paper a new method to increase the bandwidth of Rogowski current sensors is presented. Instead of using a termination resistor, in the proposed method a simple circuit based on transimpedance amplifier is used to suppress the parasitic capacitance of the coil. Using the lumped model of Rogowski coil, bandwidth, gain, and noise of the proposed current sensor is analyzed. The analyses are validated by both simulation and measurement results. Measurement of the proposed circuit demonstrates that without having any special coil design, a bandwidth close to 12 MHz can be achieved, using a simple circuit with off-the-shelf electronic components.