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  2. Per-unit system - Wikipedia

    en.wikipedia.org/wiki/Per-unit_system

    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.

  3. 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, =

  4. 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]

  5. Orders of magnitude (current) - Wikipedia

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

    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 ...

  6. Power factor - Wikipedia

    en.wikipedia.org/wiki/Power_factor

    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

  7. Electric power - Wikipedia

    en.wikipedia.org/wiki/Electric_power

    Electric power is the rate of transfer of electrical energy within a circuit.Its SI unit is the watt, the general unit of power, defined as one joule per second.Standard prefixes apply to watts as with other SI units: thousands, millions and billions of watts are called kilowatts, megawatts and gigawatts respectively.

  8. Electric motor - Wikipedia

    en.wikipedia.org/wiki/Electric_motor

    An industrial electric motor . An electric motor is a machine that converts electrical energy into mechanical energy.Most electric motors operate through the interaction between the motor's magnetic field and electric current in a wire winding to generate force in the form of torque applied on the motor's shaft.

  9. Capacitive power supply - Wikipedia

    en.wikipedia.org/wiki/Capacitive_power_supply

    A lamp that has 48 LEDs - 3 W/230 V. By changing the value of the example in the diagram by a capacitor with a value of 330 nF, a current of approximately 20 mA can be provided, as the reactance of the 330 nF capacitor at 50 Hz calculates to = and applying Ohm's law, that limits the current to .