Rogowski coil current transducer compensation method for harmonic active power error

• Two Rogowski coil current transducers are characterized in different distorted conditions.
• The harmonic ratio errors and phase displacements are evaluated and corrected.
• The correction method is based on the frequency response.
• The harmonic power measurement accuracy is also increased.
• Rogowski coil transducers should be preferred to CT in power quality measurements.

In the harmonic active power measurement, the highest uncertainties are generally introduced by the current and voltage transducers. In a previous paper, the authors showed that the current transformer (CT) can introduce significant errors in such measurement, especially if the phase shift between voltage and current is close to ±90°. In such condition the errors on harmonic power measurement are mainly due to the CT phase displacement. This paper shows that better results can be achieved with more linear transducers, such as the Rogowski coil current transducers (RCCTs), whose metrological performance in distorted condition can be improved, by means of a proper compensation method. The proposed method for RCCTs compensation is based on the frequency response and it allows to reduce the errors on harmonic power measurement, also for phase shift close to ±90°. The study is supported by several experimental tests.