Distribution bays : to PAC or not to PAC? : that's the question!

In 2010 Enexis investigated the possibilities how to equip their distribution bays in the 10kV substations with PAC-equipment. The substations are pretty simple (single busbar, no redundant DCsupply, etc.) so the PAC solution should also be simple. The functional need that has been specified is to collect measurement data and events from the substations and to control the bays from the control room. The paper will describe which choices are made and for what reason. Besides that it will explain how Enexis uses IEC-61850 in a kind of a light version. This because some benefits of IEC-61850 (standard data objects and high performance) are valuable in this situation but other typical characteristics of IEC61850, such as the way of engineering, the application of GOOSE messages, and possibilities for interlocking, are not required in this relatively simple substations. More and more automation is introduced in the distribution networks, also at a ‘lower level’. In these applications the required functionality is rather limited. Using only a limited part of IEC61850, as a kind of ‘IEC61850 light’ might probably also be interesting in these cases.