FAQ
What is the difference between input power and oscillating power (sometimes referred to as output power)?
Input power (Kw) is the product of the input voltage and current. Output Power or oscillating power (Kva) is a product of the output voltage and current in addition to reactive power (Kvar).
What is reactive power (var)?
Reactive power exists in an AC circuit when the current and voltage are not in phase, var is the unit in which reactive power is expressed in an AC power system
Reactive power is the difference between va (apparent power) and w (true power), it is the imaginary component of apparent power that does not contribute to the work load. var = va - w : (volt amp reactive = volt amp - watts)
Reactive power Q, which is a measure of the rate of energy that is sloshing back and forth between an AC source and a reactive (capacitive or inductive) load. It is measured as the product of the RMS voltage, current and the sin of the angle of difference between voltage and current (+ or - 90 degrees). Q = Vrms * Irms * sin(phase angle between the current and voltage)
In the beer analogy below real power that flows to the load and does work (Kw) is expressed as the beer. The imaginary or reactive power (Kvar) is represented by the foam. The apparent power in the circuit that the system must be able to handle (Kva) is represented by the beer + the foam.
What is Power Factor?
Power Factor is the unit used to describe the ratio of real to apparent power in an AC circuit.
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