IEEE 145-2000 pdf download IEEE Trial-Use Standard Denitions for the Measurement of Electric Power Quantities Under Sinusoidal, Nonsinusoidal, Balanced, or Unbalanced Conditions
1.Overview
This trial-use standard is divided into three clauses. Clause 1 lists the scope of this document, Clause 2 listsreferences to other standards that are useful in applying this trial-use standard. Clause 3 provides the definitions,among which there are several new expressions.
The preferred mathematical expressions recommended for the instrumentation design are marked with asign. The additional expressions are meant to reinforce the theoretical approach and facilitate a bettelunderstanding of the explained concepts.
1.1 Scope
This is a trial-use standard for definitions used for measurement of electric power quantities under sinusoidal, nonsinusoidal, balanced. or unbalanced conditions. It lists the mathematical expressions that were usedin the past, as well as new expressions, and explains the features of the new definitions.
1.2 Purpose
This trial-use standard is meant to provide organizations with criteria for designing and using meteringinstrumentation.
2. References
This trial-use standard shall be used in conjunction with the following publications. If the following publica-tions are superseded by an approved revision, the revision shall apply.
DIN 40110-1997,Quantities Used in Alternating Current Theory.IEEE Std 280-1985 (Reaff 1997), IEEE Standard Letter Symbols for Quantities Used in Electrical Scienceand Electrical Engineering.
ISO 31-5:1992.Ouantities and Units–Part 5: Electricity and Magnetism.
3. Definitions
Mathematical expressions that are considered appropriate for instrumentation design are marked with thesign . When the signappears on the right side, it means that the last expression that is listed isfavored. Each descriptor of a power type is followed by its measurement unit in parentheses.
3.1 Single-Phase
3.1.1 Single-Phase sinusoidal
A sinusoidal voltage source
v=2V sin(wt)
supplying a linear load, will produce a sinusoidal current of
i =21 sin(wt-0)
where
vis the rms value of the voltage (V)
is the rms value of the current (A)
is the angular frequency 2nf(rad/s)
is the frequency (Hz)
is the phase angle (rad)
is the time (s)
3.1.1.1 Instantaneous power (W)
The instantaneous power p is given by
lp = vi
p = Pa+Pq
where
Pa = VIcos日[1- cos(2wt)] = [1- cos(2r)]:P = VIcos日Pq =-VIsin0sin(2wr) = -Qsin(2wt):Q= VIsin0
NOTES
1–The instantaneous power is produced by the active component of the current, .e. the component that is in phase withthe voltage. It is the rate of flow of the energy
wa = fPadt = Pt-2sin(2wt)This energy flows unidirectionally from the source to the load. Its rate of fow is not negative, p,2 0.2–The instantaneous power p, is produced by the reactive component of the current, i.e., the component that is inquadrature with the voltage. It is the rate of flow of the energyw, = fp,d = cos(2w)
This type of energy oscillates between the source and inductances, capacitances, and moving masses pertaining to elec-tromechanical systems (motor and generator rotors, plungers, and armatures). The average value of this rate of fow iszero, and the net transfer of energy to the load is nil.
efn

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