A Rogowski coil assembly includes a first Rogowski coil that surrounds a conductor and generates a first voltage output signal. A second Rogowski coil also surrounds the conductor. The second Rogowski coil generates a second voltage output signal. A relay device communicates with the first and second Rogowski coils and processes the first and second voltage output signals. For example, the relay device can process the voltage output signals to calculate an amount of noise in the first and second output voltage signals and/or to minimize the amount of noise in the first and second output voltage signals.