by Alex Apostolov, Editor-in-Chief

It is a Whole New World

The electric power industry is in the process of transition from protection relays with a limited exchange of binary signals between them to intelligent protection, automation and control systems based on exchange of data sets between multifunctional Intelligent Electronic Devices (IEDs) over communication networks. This requires a change in the mindset and the knowledge base of PAC specialists.

The goal of this issue of the PAC World magazine is to open a discussion on the many questions that this transition is raising. There is a lot of fear, and as usual the fear is of the unknown.
To a great extent this is due to the fact that communications in general and communication networks in particular are something new to most of the specialists in our industry.

At the same time they play a key role being in the center of any PAC system. Which leads to questions such as:

  • What technology should we use?
  • What network architecture should we use?
  • Will it meet the functional specification requirements?
  • Will it meet the performance requirements?
  • How reliable is it?
  • Is it protected from cyber attacks?

And there are many, many more questions that each of us can ask.

Our task will be much easier if we live in a simple world with an electric power grid like the one we had in the last century - a grid with a limited number of small, medium and large electric power stations connected to a transmission system delivering power to the users through a radial distribution system supplied only through the substation’s power transformers. Such a grid can reasonably be protected and controlled by devices with limited functionality and communications capabilities.
The price to pay for the large scale penetration of renewable resources at all levels of the electric power grid is that it changes dramatically the behavior of the system under normal and abnormal conditions and requires the use of distributed adaptive PAC systems.

Considering that we need to perform functions of different types and with different performance requirements, we need to develop a system that can meet them in the most efficient way. In the core of such efficient solutions is the communication network.
Developing a communication network is not a simple task. It can ensure that the system will be reliable and secure, while at the same time fast and efficient.

The articles in the magazine cover several important issues that need to be considered when designing, implementing or maintaining a communications based PAC system. They look at communications based digital substations, analyze the communication alternatives for a line differential protection, describe the use of routable IEC 61850 GOOSE messages or talk about the monitoring and testing of communication networks, 
They demonstrate that state-of-the-art communication technology can be used to meet any goals specified by the users of today’s PAC systems.

"A system is a network of interdependent components that work together to try to accomplish the aim of the system. A system must have an aim. Without the aim, there is no system."

W. Edwards Deming


BeijingSifang June 2016