What is the formula to find the Reactive Power (Q) in a 3 Phase System?

The formula for Reactive Power (Q) in a 3 Phase System is expressed as Q = sqrt(3) * Vl * Il * sin(θ). This equation arises from the definition of power in alternating current (AC) systems, where power components are broken down into real power (measured in watts), reactive power (measured in VARs), and apparent power.

In a three-phase system, the total reactive power is calculated by taking into account the phase shift between the current and voltage, represented by the sine of the angle θ. The 'sqrt(3)' factor accounts for the three-phase nature of the current and voltage components, amplifying the overall reactive power derived from a single phase.

The variable Vl represents the line-to-neutral voltage and Il represents the line current. The sine function reflects the contribution of the reactive power, which is associated with the magnetic fields in inductive loads or the electric fields in capacitive loads. This is critical in understanding how much of the power is 'used' in creating reactive fields as opposed to doing useful work.

Overall, when analyzing reactive power in a three-phase system, the correct application of these variables and the specific factors—particularly the use of the sine function for the phase angle—is essential