CPC 100 V1.414 - 38CT Rogowski (Ratio)Use the CTRogowski test card to measure a Rogowski coil’s ratio by injectingcurrent up to 800 A from CPC 100 800A AC output or up to 2000 A using theCP CB2 current booster connected to the "EXT. BOOSTER" output into thecurrent-carrying conductor, and by measuring the induced voltage at the end ofthe Rogowski coil windings.A Rogowski coil’s induced voltage is proportional to the conductor currentdifferentiated with respect to time. Therefore, in order to acquire a directequivalent of the conductor’s current, the induced voltage needs to beintegrated. In general, a Rogowski coil’s output signal is either lead via anintegrating amplifier or fed into an electronic protection relay with integrator. TheCTRogowski test card integrates the Rogowski coil’s output signal at theCPC 100 input V2AC.Disconnect the Rogowski coil’s output signal from the electronic protection relay,and plug it into CPC 100 V2AC input.The CTRogowski test card measures the amplitude of the injected currentIprim and the Rogowski coil’s output voltage Vsec, integrates this signal, andcalculates the secondary current Isec, its phase angle as well as the actual ratioand the deviation.Figure 22:Setup for a CT ratio testof a Rogowski coilPlease refer to the note below.electronicprotectionrelay withintegrator(forexample150mV atShielded cable withtwisted wires.Shield connectedto Rogowski coil.P1P2
