Imagine removing all the Single Line Diagram information (CB, CT, VT ..) off all the conventional wiring diagrams for a substation and then combining all the wiring diagrams onto one huge drawing !!
Then come back 5 years later and add another bay for a new feeder .... what bit relates to a particular bay? We never started designing wire based systems by drawing wires between relays then adding a CT, circuit breaker and bay and then a voltage level. Yes we developed templates over time of the schemes related to a certain type of bay but we always start with the Single Line Diagram. It seems in the rush to be able to sell (their) boxes, the vendors have pushed the focus on the device configuration - I don't blame them - they have to make money after all the investment and there were very limited Specification Tools available previously. Binding of functions to the topology of the substation and the primary plant is a fundamental aspect of conventional wire based designs. Functions do not happen to appear 'somewhere in the substation". The ENTSO-E Statement and subsequent clone VLPGO Statement both indicate that attempts to augment existing IEC 61850 substations has proved virtually impossible.
The ENSTO-E Report then goes into their view on how to move forward. Perhaps these problems are at least partially because of the lack of Substation section in the SCL files associated with the projects. The Substation section is effectively defined by the creation of the SSD file by the System Specification Tool. Of course their statements are generalised and non specific, but in simple terms, if the SCD file is not constructed specifically based on the SSD as the starting point, there is no structure created in the final SCL files of a voltage level or a bay. It then becomes impossible to add another bay when a new feeder is added or a second transformer etc. since the "bay" simply doesn't exist in the XML structure - they are all just a bunch of IEDs connected to a LAN. The real meaning of "supports SSD" needs to be well understood in each case as it is equally as vague as saying "the IED complies to IEC 61850" Users need to know precisely in what respect. Does it create SSD, does it export them, does it do so totally independently of the subsequent choice of boxes, can you view the SLD from a SCD file with this structure ... and many more such questions |