Modern Ied Data Capture Configuration Challenges

Modern digital protective devices, sometimes called Intelligent Electronic Devices (IEDs), typically have a vast array of data collecting capabilities, but a finite memory in which to store the collected data. Errors in IED configuration can result in critical data being missing or obscured, either because it wasn’t captured or because the available memory was full of irrelevant data. For example, many IEDs can store information concerning protective function type, pick-up value, timestamp, and power system values immediately before, during and following a trip event. Almost every parameter or variable and a wide variety of analog data can be stored. When configured appropriately, this data can simplify fault investigations, expedite power system restoration and provide valuable data for avoiding future incidents. Hence, there is great value in understanding the digital protective relay, the application, and the common failure modes at the outset when configuring a digital protective relay. The purpose of this paper is to recommend IED data storage schemes for commonly encountered applications based on the collective experiences of the authors.