Final Thoughts

Make your choice

Every quarter we post a question on the PAC World web site and ask you to select an answer that will help your colleagues from around the world understand the trends in our industry.

No clear preference

For three months we had on the PAC World web site a simple question:

What redundant protection do you use on transmission lines?

The answers to the questions you can choose from and the percentage of responders that selected them are as follows:

  • Same type and same manufacturer: 34.9%
  • Same type and different manufacturer: 23.5%
  • Different type and same manufacturer: 21.1%
  • Different type and different manufacturer: 20.5%

The results from this non-scientific poll are shown in the chart to the right. As in the previous survey the number of people that decided to pick one of the four answers is relatively small - 166. I would like once again to say that it is not that difficult to take part in it, while by clicking on an answer that you select you will make an important contribution to our understanding of industry practices.

If we analyze the result it is clear that one thirds of the participants prefer to use both relays of the same type and same manufacturer. The remaining three options are evenly distributed - at about 20% each.

This is probably due to the fact that the decision for selection of redundant transmission line protection relays are based on many different factors, such as economics, training, maintenance, protection philosophy, etc.

The new question on the web site is related to the main subject of the Spring 2008 issue - power systems analysis:

What type analysis tools do you use related to protection and control?

The answers that you can choose from are:

  • Short circuit and protection coordination,
  • Electromagnetic transient simulation,
  • Both,
  • None.

Please take a minute, go to the web site page and click on your choice.
-- Alex Apostolov

PDF Version

Power. Flexible. Easergy.
BeijingSifang June 2016