Uncertainty of measurement error in intelligent electronic devices

This paper focuses on methodology to quantify uncertainty in measurements obtained from Intelligent Electronic Devices (IED). IEDs have emerged in distribution systems as a prevalent source of measurements in monitoring and protection, as well as for different kinds of applications beyond IED´s primary purposes. These measurement devices are installed across a system, from substations down to the customer locations, and provide measurements of a wide array of quantities. We report how IED measurements respond to external disturbances, which may lead to possible accuracy impacts in various applications. The example used to illustrate the approach is highly accurate fault location in distribution systems based on voltage sag measurements.