Reactive Load and Power factor

Reactive load refers to the load that is in consequence of the impedance or the capacitance of the load. Thus when a capacitive or inductive load is connected to a power source a current flows through the load which does not produce any active power consumption (kW). This charging current is called the reactive current (I .Sin φ).

The power caused by this current is called the reactive power. It is denoted by Q .

Q= V x I x cos φ

The reactive power is measured by kVAr (Reactive Kilo Volt ampere). The higher the value of the reactive load, the lower the power factor. For example, as a motor consumes more reactive power its power factor decreases.  This is evident from the following diagram.

As the reactive power decreases, the power factor increases.

Alternatively, the power factor is the ratio between the Active power, P and the Apparent Power, S

Cos φ = P/S

Popular Posts