For a small view of reactive power, consider a motor in your window fan. You plug its electrical cord into a wall socket and electricity flows into the fan motor when you turn it on.
That electricity does three things.
- It produces current in the motor.
- It produces magnetism in the motor to react with the current to make the motor rotate and spin the fan.
- It makes the motor hot.
Parts 1 and 3 are considered real power because it produces effects such as speed, torque and temperature that you can directly measure. It is also the part that the power company charges you for.
Part 2 is the reactive power. It puts the motor in a condition to do work but does no work itself. It’s analogous to us having ‘attitude’. If we have an attitude to do some work, things get done. If there is no attitude we are just couch potatoes.
For you to do anything useful with this concept, you would have to understand the mathematics that are used to describe electric power.
Electrical engineers and technicians learn about volts and amps, inductive and capacitive reactance, frequency and complex numbers.
Most of the load on the system is inductive in nature where current lags voltage. Now if you use a capacitor where current leads voltage you can reduce the angle between current and voltage in the resultant diagram. Remember that power factor is the cos of angle between the two which means the lesser is the value of angle more will be the value of power factor.