Realising the Benefits of Non-Conventional Sensors

The integration of protection and measurement functions into one device has been developing for many years, and has proven field experience, resulting in reductions in the number of system components and wiring. However, whilst still using conventional instrument transformers, a drawback of this level of integration has been in compromising the accuracy of measurement information whilst maintaining the sensitivity of the protection due to the saturation effects caused by the iron core in current and voltage transformers. Non-conventional sensors such as Rogowski Coils and voltage dividers are not subject to magnetic saturation effects and so provide a solution with no saturation. However, the take-up of this technology is not strong. This paper reviews some of the incentives to using sensors for protection and measurement applications, and tries to provide a deeper understanding of the advantages to both the switchgear manufacturers and end users of using Rogowski Coils and voltage dividers on Medium Voltage switchgear.