Event

Part 1 presenter : Roberto Tinarelli
In recent years, Low Power Instrument Transformers (LPITs) have progressively replaced conventional inductive ITs due to their superior accuracy, reliability, bandwidth, and dynamic response.
A major concern is the long-term stability of their metrological performance, which may deteriorate over time because of physical, chemical, and electrical aging processes affecting the materials and components. Although aging phenomena in electrical equipment have been widely studied, only limited research has focused on the metrological stability of ITs, especially LPITs.
The tutorial focuses on:
- Ageing of ITs in scientific literature and standards
- Summary of the results of a survey involving manufacturers and utilities
- WG proposal on how to consider the effect of ageing
Part 2 presenter : Paolo Mazza
Instrument transformers accuracy is crucial for voltage, current and energy measurements in high voltage, for both traditional and new applications.
At present, instrument transformers accuracy is in most cases assessed at the Manufacturers’ or third-party calibration laboratories; however, in some cases, it can be necessary or desirable, for various reasons, to perform accuracy tests onsite.
While the framework (equipment, conditions, procedures, uncertainty evaluation…) relevant to laboratory test is well known, much less experience and references are available with reference to on-site calibration. In this tutorial, an overall introduction of this subject and the results of the activity of CIGRE WG A3.50 “On-site calibration and verification of the accuracy of instrument transformers” will be presented.