ⓘ COMTRADE is a file format for storing oscillography and status data related to transient power system disturbances. COMTRADE files are typically created by inte ..

                                     

ⓘ Comtrade

COMTRADE is a file format for storing oscillography and status data related to transient power system disturbances.

COMTRADE files are typically created by intelligent electronic devices, explosive devices, such as electronic protective relays, electrical substations in the system of eating disorders. These IEDs to control the electrical characteristics of the power system by digital sampling measurement of current, voltage, power, frequency, etc. at high speed. Then IEDs used digital signal processing algorithms of these 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 errors are detected, the IEDs will record the digitized time data of faults that was used during processing to a file in Comtrade format file. Then, analysis tools can download a file of COMTRADE and to calculate useful information related to the violation. For example, COMTRADE record of the fault current is absorbed by the transformer to the switch opening can be used to calculate the total energy dissipated in the transformer which will help the utility to more accurately estimate the effect of this error on the service life of the transformer. COMTRADE files from multiple substations can be used for forensic analysis of large scale perturbations of the power events such as blackouts, to determine the cause of the violations and improve the protection system and planning future strategies for mitigation.

The COMTRADE file format has been standardized by the power system relaying Committee and management of CRPS in the IEEE power and energy society, as C37.111. The most widely used version of the COMTRADE standard C37.111-1999, but the latest version is C37.111-2014. The 1999 version of the COMTRADE standard specifies a file format, which consists of several file types assigned to files with extension *.File cfg, *. INF *.HDR and *.Date. In *.The DAT file contains the digitized sample data in an ASCII text format. In *.Cfg the configuration file contains information about that *.DAT file, including information such as the names of the signal, the start time of samples, number of samples, min / max values, and more. Only *.Cfg and *.DAT files were required. Although the values of digitized samples *.The DAT file can be viewed without *.Cfg file, the value of data decreases significantly as it would be very difficult to fully reconstruct the meaning of data without *.The cfg file.

As applications for use COMTRADE increased restrictions on the file format was causing the problem. For example, North American SynchroPhasor initiative NASPI support the North American reliability Corporation NERC electric power wanted to use a database file format for data exchange synchrophasor. On The C37.111-1999 the version of COMTRADE *cfg the file specified in the ASCII character set only supported companies analog and digital data types of data and does not transmit any power information on the system configuration. This would make large scale synchrophasor data exchange more difficult. Starting in 2011, the IEEE PSRC began work on a new version of the standard COMTRADE, which was published as C37.111-2013. Also known as IEC 60255-24 ed.2, This standard defines a format for files containing transient waveform and event data collected from power systems or power system models. The format is designed to provide an easy to interpret form for use in a data exchange. The standard is for files stored on currently used physical media such as portable external hard drives, USB drives, CD or DVD. The standard COMTRADE does not specify how to transfer data files through a communication network.

Version of the standard COMTRADE 2014 supports many new features, including configuration, coding, and XML data, one file type *.The FSF, which brings together all C37.111-1999 types into one file, additional data types for 32-bit binary and floating-point values and partial binary encoding to reduce file size.

The quality Subcommittee of the IEEE power and Energy community IEEE is also specified the file format, the quality of the power interchange format PQDIF data in IEEE STD.1159.3-2019 that is similar to COMTRADE in structure, but is mainly used to transmit data on the quality of food and not the time the data breach. As the COMTRADE standard IEEE PQDIF IEEE can be used to exchange measurements, waveform and vector measurements. However, PQDIF IEEE allows to store logs of data value duration of measurements, histogram and much more.

There are numerous COMTRADE viewers and software for analysis is available from many commercial companies, as well as:

* free viewers like PQDiffractor, TOP, GTPPLOT * free analysis software like Comcalc Pro includes multi-file viewing capabilities.

Preview / analysis of the functionality varies. Some free COMTRADE viewers and analysis software also includes additional advanced features.