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IEEE 1344
IEEE 1344 is a standard that defines parameters for synchrophasors for power systems. The standard added extension to the IRIG-B time code to cover year, time quality, daylight saving time, local time offset and leap second information. IEEE 1344 was superseded by IEEE C37.118 in 2005 and the time extensions were adopted as part of the IRIG timing standard in the 2004 edition. IRIG-B timecode consists of 100 bits, repeated each second. Every tenth bit is a "position identifier", and most of the remainder encode the current time (date, hour, minute and second). Bits 60–68 and 70–78 are reserved for other uses; IEEE 1344 is such a use. It defines the bits as follows: The DST and leap warning bits are set no more than 59 seconds before the indicated change, and indicate the change at the end of the minute. During a leap second, the warning bit should be set, the seconds field should show "60", and the Straight Binary Seconds field should equal 60 + 60 × minutes + 3600 × ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Synchrophasors
A phasor measurement unit (PMU) is a device used to estimate the magnitude and phase angle of an electrical phasor quantity (such as voltage or current) in the electricity grid using a common time source for synchronization. Time synchronization is usually provided by GPS or IEEE 1588 Precision Time Protocol, which allows synchronized real-time measurements of multiple remote points on the grid. PMUs are capable of capturing samples from a waveform in quick succession and reconstructing the phasor quantity, made up of an angle measurement and a magnitude measurement. The resulting measurement is known as a synchrophasor. These time synchronized measurements are important because if the grid’s supply and demand are not perfectly matched, frequency imbalances can cause stress on the grid, which is a potential cause for power outages. PMUs can also be used to measure the frequency in the power grid. A typical commercial PMU can report measurements with very high temporal resolution, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IRIG Timecode
Inter-range instrumentation group timecodes, commonly known as IRIG timecode, are standard formats for transferring timing information. Atomic frequency standards and GPS receivers designed for precision timing are often equipped with an IRIG output. The standards were created by the Tele Communications Working Group of the U.S. military's Inter-Range Instrumentation Group (IRIG), the standards body of the Range Commanders Council. Work on these standards started in October 1956, and the original standards were accepted in 1960. The original formats were described in IRIG Document 104-60, later revised and reissued in August 1970 as IRIG Document 104-70, upgraded later that year as the IRIG Document to the status of a Standard, IRIG Standard 200-70. The latest version of the Standard is IRIG Standard 200-16 from August 2016. Timecodes The different timecodes defined in the Standard have alphabetic designations. A, B, D, E, G, and H are the standards currently defined by IRIG S ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IEEE C37
The Institute of Electrical and Electronics Engineers (IEEE) is a 501(c)(3) professional association for electronic engineering and electrical engineering (and associated disciplines) with its corporate office in New York City and its operations center in Piscataway, New Jersey. The mission of the IEEE is ''advancing technology for the benefit of humanity''. The IEEE was formed from the amalgamation of the American Institute of Electrical Engineers and the Institute of Radio Engineers in 1963. Due to its expansion of scope into so many related fields, it is simply referred to by the letters I-E-E-E (pronounced I-triple-E), except on legal business documents. , it is the world's largest association of technical professionals with more than 423,000 members in over 160 countries around the world. Its objectives are the educational and technical advancement of electrical and electronic engineering, telecommunications, computer engineering and similar disciplines. History Origins ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Daylight Saving Time
Daylight saving time (DST), also referred to as daylight savings time or simply daylight time (United States, Canada, and Australia), and summer time (United Kingdom, European Union, and others), is the practice of advancing clocks (typically by one hour) during warmer months so that darkness falls at a later clock time. The typical implementation of DST is to set clocks forward by one hour in the spring ("spring forward"), and to set clocks back by one hour in the fall ("fall back") to return to standard time. As a result, there is one 23-hour day in early spring and one 25-hour day in the middle of autumn. The idea of aligning waking hours to daylight hours to conserve candles was first proposed in 1784 by U.S. polymath Benjamin Franklin. In a satirical letter to the editor of ''The Journal of Paris'', Franklin suggested that waking up earlier in the summer would economize on candle usage; and calculated considerable savings. In 1895, New Zealand entomologist and astronome ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Even Parity
A parity bit, or check bit, is a bit added to a string of binary code. Parity bits are a simple form of error detecting code. Parity bits are generally applied to the smallest units of a communication protocol, typically 8-bit octets (bytes), although they can also be applied separately to an entire message string of bits. The parity bit ensures that the total number of 1-bits in the string is even or odd. Accordingly, there are two variants of parity bits: even parity bit and odd parity bit. In the case of even parity, for a given set of bits, the bits whose value is 1 are counted. If that count is odd, the parity bit value is set to 1, making the total count of occurrences of 1s in the whole set (including the parity bit) an even number. If the count of 1s in a given set of bits is already even, the parity bit's value is 0. In the case of odd parity, the coding is reversed. For a given set of bits, if the count of bits with a value of 1 is even, the parity bit value is set ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IEEE Standards
The Institute of Electrical and Electronics Engineers (IEEE) is a 501(c)(3) professional association for electronic engineering and electrical engineering (and associated disciplines) with its corporate office in New York City and its operations center in Piscataway, New Jersey. The mission of the IEEE is ''advancing technology for the benefit of humanity''. The IEEE was formed from the amalgamation of the American Institute of Electrical Engineers and the Institute of Radio Engineers in 1963. Due to its expansion of scope into so many related fields, it is simply referred to by the letters I-E-E-E (pronounced I-triple-E), except on legal business documents. , it is the world's largest association of technical professionals with more than 423,000 members in over 160 countries around the world. Its objectives are the educational and technical advancement of electrical and electronic engineering, telecommunications, computer engineering and similar disciplines. History Origins ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
