IEEE C37.118.1-2011 pdf download IEEE Standard for Synchrophasor M easurements for Power Systems
2. Normative references
The following referenced documents are indispensable for the application of this document (i.e., thcy mustbe understood and used, so each referenced document is cited in text and its relationship to this document isexplained). For dated references, only the edition cited applies. For undated references, the latest edition of
the referenced document (including any amendments or corrigenda) applies.
IEEE Std 7541M-1985, IEEE Standard for Binary Floating-Point Arithmetic.2, 3
3. Definitions, acronyms, and abbreviations
For the purposes of this document, the following terms and definitions apply. The IEEE StandardsDictionary: Glossary of Terms & Definitions (B2] should be consulted for terms not defined in this clause.
31 Definitions
anti-aliasing: The process of filtering a signal before sampling to remove components of that signal whoscfrequency is equal to or greater than the Nyquist frequency (one-half the sample rate). If not removed, thescsignal components would appear as a lower frequency component (an alias).
Coordinated Universal Time (UTC): (Initials are ordcred based on French language.) The time of day atthe Earth’s prime meridian (0° longitude). It is distributed by various media, including the GlobalPositioning System (GPS) system.
data concentrator (DC): A device that combines data from several measurement devices.
frequency error (FE): The measure of error between the theoretical frequency and the measuredfrequency for the given instant of time.
Global Positioning System (GPS): A U.S. Department of Defense (DoD) navigation system that uses aconstellation of 24 satellites broadcasting a precision signal for location and time synchronization. Basictime synchronization accuracy is 土 0.2 microseconds (us).
IEEE floating point: A 32-bit representation ofa real numberNOTE-This definition is in accordance with IEEE Std 754-1985.
leap second: A positive or negative one-second adjustent to the Coordinated Universal Time (UTC) thatkeeps it close to mean solar time.
Nyquist frequency: A frequency that is one-half the sampling frequency of a discrete signal processingsystem.
Nyquist rate: A sampling rate that is twice the bandwidth of a band-limited signal. It is the minimunisample rate that will result in an alias-free representation of a signal. It must therefore be greater than twicethe highest frequency component in the signal.