General information

Comtrade file format

The COMTRADE (IEEE Standard Common Format for Transient Data Exchange) standard defines a standard format for data files and other files required to represent faults, tests, or simulations. Up to 4 file types can be generated with extensions*. HDR, *. CFG, *. DAT and *. INF.

• HDR (Header) - It is an optional text file. It contains general information about the event. It is written in ASCII format and its contents do not need to be stored in a specific order.

• CFG (Configuration) - It is a required text file. It is recorded in ASCII format and its content is organized to allow its automated reading, through a computational algorithm. It consists of data such as the substation name, number of analog and digital channels, channel names, units, conversion factors, electrical system frequency, sampling rates, date and time, and the format in which the data file was recorded.

• DAT (Data) - It is a mandatory text file. It is written in ASCII or binary format. It contains only numbers and corresponds to samples taken of analog and digital quantities. Its correct interpretation depends on the information contained in the configuration file. In the configuration file are specified means to translate these values accordingly to real quantities, such as volts and amperes. Digital data is represented by the digits "0" and "1".

• INF (Information) - It is an optional text file. It is recorded in ASCII or UTF-8 format. It contains extra information beyond the minimum required for the application of the dataset. The format provides information that can be read and used by any user, and information that can be accessible only to users of a particular class. The information store is divided into sections, which can be of the public or private type. Each section consists of a header line followed by a certain number of input lines. Public sections contain information that can be used by equipment and software of various types of manufacturers, private sections contain information that can be used only by a specific manufacturer of software, hardware, or equipment.

Oscillography Data Collection

Whenever a substation protection relé generates a new oscillography file due to an electrical system disturbance, through a report the existence of the new file will be signaled and the local SCADA will collect this file using the IEC61850 protocol directives and arrange for it to be sent to the CCO UCI.

The protocol IEC61850 second edition SCADA Action˳NET was approved by the DNV-GL (Netherlands) supporting function 14 that implements the transfer of oscillography files from IEDs servers IEC61850.

In the section of NODES configuration, the Primary station can be seen the parameterization window of a node (IED) of an IEC61850 channel where it is reported:

• Comtrade file Reading mode: download or Download & Delete;

• Comtrade files Comtrade folder: destination directory where the file will be stored;

• Comtrade files download pooling rate: if greater than zero sets the frequency of checking the existence of Comtrade files;

• Download Comtrade files when receiving a report: Download from the on-demand file. A report is inserted signaling the existence of a new file.

Reading and Writing

The driver will scan the IED file directories in search of files with the *extensions. HDR, *. CFG, *. DAT and *. INF. This scan will be done by MMS or FTP, every X period and saved to a computer directory according to settings set on the node.
If the file already exists in the directory, it will have its name and last modification date compared to that of the file in the IED, and this defines whether the file should be transferred or deleted if this option is enabled in the node configuration.
Operations are recorded at the DEBUG level in the LOG file. And they will be recorded if the log level in the channel configuration is set to DEBUG. For cases where FTP is used, a new LOG file named FTP.log is generated within the folder of each channel. It has been separated to have a better debugging organization when the operation uses FTP to read the COMTRADE files.