Comtrade

COMTRADE (Common format for Transient Data Exchange for power systems) is a file format for storing oscillography and status data related to transient power system disturbances.

COMTRADE files are typically generated by Intelligent Electronic Devices (IEDs), such as an electronic protective relay, in electrical substations during power systems disturbances. These IEDs are monitoring the electrical characteristics of the power system by digitally sampling measurements of the current, voltage, power, frequency, etc. at a high speed. The IEDs then use digital signal processing algorithms on that data to detect abnormal conditions in the power system so that automated control actions can be taken to prevent damage to the power system. When faults are detected, the IEDs will record the digitized transient fault data that was used during processing into a file using the COMTRADE file format. Analysis tools can then download the COMTRADE file and calculate useful information related to the disturbance. For instance, a COMTRADE recording of the fault current absorbed by a transformer prior to the circuit breaker opening can be used to calculate the total energy dissipated by the transformer which helps the utility to more accurately estimate the impact of that fault on the lifetime of the transformer. COMTRADE files from multiple substations can be used collectively to perform forensic analysis of large scale power disturbance events (e.g. blackouts) to determine the root cause of the disturbance, help improve system protection and guide future mitigation strategies.