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  2. Volt-ampere - Wikipedia

    en.wikipedia.org/wiki/Volt-ampere

    The volt-ampere (SI symbol: VA, [1] sometimes V⋅A or V A) is the unit of measurement for apparent power in an electrical circuit.It is the product of the root mean square voltage (in volts) and the root mean square current (in amperes). [2]

  3. Per-unit system - Wikipedia

    en.wikipedia.org/wiki/Per-unit_system

    In the power systems analysis field of electrical engineering, a per-unit system is the expression of system quantities as fractions of a defined base unit quantity. . Calculations are simplified because quantities expressed as per-unit do not change when they are referred from one side of a transformer to t

  4. Mathematics of three-phase electric power - Wikipedia

    en.wikipedia.org/wiki/Mathematics_of_three-phase...

    An important property of three-phase power is that the instantaneous power available to a resistive load, = =, is constant at all times.Indeed, let = = To simplify the mathematics, we define a nondimensionalized power for intermediate calculations, =

  5. AC power - Wikipedia

    en.wikipedia.org/wiki/AC_power

    The formula for complex power (units: VA) ... Other forms of complex power (units in volt-amps, VA) are derived from Z, the load impedance (units in ohms, Ω).

  6. Orders of magnitude (current) - Wikipedia

    en.wikipedia.org/wiki/Orders_of_magnitude_(current)

    10.5 kV secondary side from an electrical substation with primary 115 kV; 63 MVA [8] 9.3 kA 2.7V, Ultracapacitor short circuit current [9] 10 4: 25 kA Lorentz force can crusher pinch [10] 30 kA Typical lightning strike 10 5: 100 kA Low range of Birkeland current that creates Earth's aurorae 140 kA

  7. Motor constants - Wikipedia

    en.wikipedia.org/wiki/Motor_constants

    This is exactly the value estimated by the formula stated earlier. EXAMPLE: Torque applied at different diameters , K v (rpm/V) {\displaystyle K_{\text{v (rpm/V)}}} = 3600 rpm/V ≈ 377 rad/s/V , K T {\displaystyle K_{\text{T}}} ≈ 0.00265 N.m/A (each calculatable if one is known) , V = 2 v, I a {\displaystyle I_{\text{a}}} = 2 A, P = 4 W ...

  8. Mean value analysis - Wikipedia

    en.wikipedia.org/wiki/Mean_value_analysis

    In queueing theory, a discipline within the mathematical theory of probability, mean value analysis (MVA) is a recursive technique for computing expected queue lengths, waiting time at queueing nodes and throughput in equilibrium for a closed separable system of queues.

  9. Capability curve - Wikipedia

    en.wikipedia.org/wiki/Capability_curve

    Hydrogen-cooled turbo generator's cooling can be improved by increasing the hydrogen pressure, larger generators, from 300 MVA, use more efficient water cooling. [3] Capability curve of a synchronous generator with minimum load. The practical D-curve of a typical synchronous generator has one more limitation, minimum load. The minimum real ...