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The base value should only be a magnitude, while the per-unit value is a phasor. The phase angles of complex power, voltage, current, impedance, etc., are not affected by the conversion to per unit values. The purpose of using a per-unit system is to simplify conversion between different transformers.
400 V low voltage secondary side distribution transformer with primary 12 kV; 200 kVA (up to 1000 kVA also common) [7] 10 3: 2 kA 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 ...
is the motor velocity, or motor speed, [2] constant (not to be confused with kV, the symbol for kilovolt), measured in revolutions per minute (RPM) per volt or radians per volt second, rad/V·s: [3]
In the case of devices that output a different voltage than the battery, it is the battery voltage (typically 3.7 V for Li-ion) that must be used to calculate rather than the device output (for example, usually 5.0 V for USB portable chargers). This results in a 500 mA USB device running for about 3.7 hours on a 2,500 mAh battery, not five hours.
In electrical engineering, the power factor of an AC power system is defined as the ratio of the real power absorbed by the load to the apparent power flowing in the circuit. . Real power is the average of the instantaneous product of voltage and current and represents the capacity of the electricity for performing
kVA—One thousand volt Ampere (measurement) kvar—one thousand vars (measurement) kW—Kilowatt (one thousand watts) (measurement) kWE—kilowatt electric (measurement) kWh—Kilowatt hour (one thousand watt hours) (measurement)
See Weight for detail of mass/weight distinction and conversion. Avoirdupois is a system of mass based on a pound of 16 ounces, while Troy weight is the system of mass where 12 troy ounces equals one troy pound. The symbol g 0 is used to denote standard gravity in order to avoid confusion with the (upright) g symbol for gram.
The in-rush current during re-closure will depend on many factors, however. As an example, a 250 kVA motor–generator operating at 300 ampere of full load current will require 1550 ampere of in-rush current during a re-closure after 5 seconds. This example used a fixed mounted flywheel sized to result in a 1 ⁄ 2 Hz per second slew rate. The ...