IEC 61850-7-4-2020 pdf free download

IEC 61850-7-4-2020 pdf free download.Communication networks and systems for power utility automation — Part 7-4: Basic communication structure — Compatible logical node classes and data object classes.
F.1 Statistical calculation basis
Here are some rules that have to be understood when implementing a calculation method.
• A statistical calculation transforms an “originals flow of data (indicated by ClcSrc) into ustatistical data with considered settings. These settings define the mathematical function
to apply, the condition for starting, the calculation interval duration and possible sliding, the rate of data refreshment.
• When a statistical calculation method is applied to a logical node, it is supposed to be applied independently to any ‘instMag’ value specified in the considered statistical LN (refer to Figure F.1).
• This also applies to complex CDC such as vectors CMV/DEL/WYE. If the statistical method also applies to angle per phase, then the sum of the 3 angles may be larger than
3600.
• The common data class of a statistical data, resulting from a statistical calculation, is exactly identical to the CDC of the original data it applies to (referenced by ClcSrc), then a calculation method does not change a vector into a scalar.
• The contents of a statistical LN can not include process related data objects which were not present in the original one.
• The CDC types are not allowed to add new process related attributes (fc=MX or fc=ST) except the range attribute. Other attributes, e.g. limit ranges, might be added.
• Vector time consistency supported by WYE, DEL common data class is not to be broken down but is extended to the full refreshment interval duration. Time consistency is then valid considering the refreshment interval duration (refer to Figure Fl).
• Statistical calculation may be chained. For example, a first LN can produce RMS value, then a second statistical LN can calculate an average of the considered RMS value on a certain period, then an other statistical LN can calculate the maximum of the calculated average since the last reset of this maximum value.
Example for a MAX calculation method:IEC 61850-7-4-2020 pdf free download.