Applicability of Combined Transducers for Distorted Current Metering in Electrical Substations

Abstract

Current transducers/transformers have a significant impact on the overall accuracy of the measuring system used for electrical power metering and current measurement, especially in non-sinusoidal conditions. This research concerns an evaluation of the impact of the Rogowski coil and the combined transducer on the distorted current measuring accuracy of the digital power meter. It covers a characterization of their influence in conditions similar, at present, to the high RMS value of the distorted current in order to ensure the required test scenario for the equipment designed for the power network metering purposes. It has been established that the active component—the integration circuit (voltage-to-voltage converter or voltage-to current-converter)—has the most significant effect on the overall performance of the combined transducer. However, its impact is different depending on the selected equipment. Therefore, the presented analysis and results are essential for a conscious choice of the proper current transducer for the substation equipment.

Keywords

• sensor
• Rogowski coil
• signal conditioner
• voltage integrator
• current transducer
• electrical substation equipment