What is the physical significance of KVAR (reactive power), KWH (active power). How is KVAR generated & how does it effect the system? But if KVAR is not considered a real power then why do we call it power?
Both current and voltage waveforms are assumed to be IDEAL SINUSOIDAL waveforms. If the phase difference between the input voltage and the current waveforms is defined as the phase lag angle or displacement angle.
Many electrical devices are working under the principle of electromagnetic induction, such as distribution transformers, motors, and they are relying on to establish an alternating magnetic field to the energy conversion and transfer. For the establishment of an alternating magnetic field and induced magnetic flux and electric power reactive power is required , therefore, the so-called "reactive" is not "useless" electrical power, but reactive power does not translate into mechanical energy, heat only; Therefore, in addition to the need for active electrical power to supply system, it also needs reactive power.
Physical Analogies of Reactive Power:
Suppose I want to fill a water tank with water, one bucket at a time. Only way is to climb a ladder, carrying a bucket of water and pouring the water into the tank. Once I fill up the tank, then I have to go down the ladder to get more water. In this one cycle of going up the ladder and coming down I have done some work or the energy required to go up is more than the energy required for coming down.
If I had climbed the ladder with an empty bucket, and I had come down with the same bucket I am not doing any work. The energy for upward and downward motion is the same. Though I have not done any work - worth paying for- I require some energy.
That is, the energy that it takes to go up and down a ladder carrying nothing either way requires reactive power, but no real power. The energy that it takes to go up a ladder carrying something and come down without carrying anything requires both real power and reactive power.
The analogy can be extended for explaining 3 phase system if If we put 3 ladders going up to the tank and 3 people climb up in sequence such that there is always a steady flow.
Reactive power is produced when the current waveform is out of phase with the voltage waveform due to inductive or capacitive loads. Current lags voltage with an
inductive load, and leads voltage with a capacitive load. Only the component of current in phase with voltage produces real or active power that does real work.
KVAR & KWH
Re: KVAR & KWH
