Sending a gooose message depend on parametrization of the IED. During the initial setup of IED you will define those packets or message for control and protection functions. Ussually this part is done in project. With project, you will define the parameter for question 1 and 2. Today and even in the future IED will be deployed across the distribution network. Modern and advanced functionality in IED will become nesessary for controling the distribution network with distribution resources.

Igor Ivankovic Thank you very much for your answer. What is 'project'? Can you tell me some realistic parameters that you set up for que. 1 and 2?

If you continue in this area, you will discover that the answer to all non-trivial questions begins "It depends, ..."

IEC 61850 itself defines a number of performance classes for different purposes. For protection functions inside transmission substations, a maximum data transfer time of 3 to 10ms (a quarter to a half cycle of 50 or 60Hz) is required. In distribution systems, the times are longer (e.g. five times longer) because of the differences in the design and requirements for protection in transmission and distribution. For SCADA functions reporting to an operator, 1 second is acceptable. File transfer (e.g. fault records) is even slower.

GOOSE is just one possible mechanism. It is appropriate for some functions (and was designed to meet high-speed process coordination needs of protection systems), but not for others. There is no single technology that is always a good way of meeting every requirement, and that applies to GOOSE as well as everything else.

You might think you are asking a simple question, but the answer depends on the context. To get a clearer answer, you also need to explain the background of the application you are asking about.

Your third question seems to ask "where are IEDs used". This is related to functions and has little or nothing to do with the communication protocol. Over time, the answer to this question will change as intelligent devices are used closer and closer to the "edge" of the grid. Once upon a time there were no IEDs: All protection and control devices in the grid were electromechanical. Over time, the centralized parts (e.g. transmission substation protection schemes) have been updated to IEDs. Now IEDs are used across the distribution grid (e.g. pole-top reclosers, fault passage indicators, etc.). In the future they will be in the consumer's home, office or factory. You can consider todays' smart meters and building automation systems as early kinds of consumer-level IEDs. Over time there will be an increasing number of intelligent devices in the grid, with different functions and different communication requirements.

All of this is part of the complex system of systems that is the power grid. There is almost unlimited potential to delve into the details of each part and consider the different ways that the parts can interact. You can build a career spanning decades to become expert in just a small area...

I wish you well in your studies.