AC supply what does reactive power in ac supply liberate?

Question

In AC supply there are real power and reactive power. Real power is consumed by heat meaning it liberate heat.Now my question is what does Reactive Power consume(liberate)?

Answer 1

You need to look at the type of load that creates reactive power. A heater is a resistive load and hence the power factor (PF) is 1 there is no reactive element. Power = W = A x V or W = I x I x R or I^2 R

In a 3 phase Induction motor that contains windings the power available at the shaft ouput is given by W = 1.7321 x V x A x PF this in known as the Real power the apparent power is given by VA = 1.7321 x V x A and the difference is the reactive power = W - VA or more commonly KW - KVA = KVAR

In a reactive load only part of the current is converted into mechanical power the rest is liberated as heat in the body of the motor

In a resistive load all of the current is conveted into useful power or heat    

Answer 2

In normal sense, the reactive power is not dissipated & hence must return unchanged.

Usually it goes to creating, maintaining, a magnetic field which then returns power to the source with each cycle.

Sometimes the actual work is done to move mass rather than create a field: for example in machines running as synchronous capacitors. The idea is the same, though as power absorbed during part of the cycle is returned during the other part.

I think, maybe it is not that real power liberates heat, but maybe that real power describes that part of the power that is lost, some to heat.  That power that oscillates into & out of the load, system is termed reactive. The distinction in perspective is small, but maybe significant.

Answer 3

Reactive power does not 'liberate' (transform) energy.

Reactive power is the way in how electricity change from and electrical current into space distributed fields. You must remember that electricity in composed from electromagnetic field; the electric field is 'accumulated' in capacitors, and the magnetic field is accumulated in a coil. When you applied and AC current, some of the electricity would be store in the capacitor, as and electric field, and some in a coil, as a magnetic field, as long as current flows. When current cease the fields will return as currents into the circuit.

This 'things' depends on capacitors and coils value, as well as AC frequencies, and is the base for telecommunications and signal processing.  

The reactive nature of electricity is represented as and 'imaginary vector' when you use complex numbers. All dissipative energy (the energy that left electricity and transform to other kind of energy are in the 'real' vector, and all the reactive part, (the energy that remain as electricity but stored as fields) are in the 'imaginaryy' vector.