Types of AC powers

Electric power is the rate/unit time, at which electrical energy is transferred in an electrical system. the S.I unit of power is the watt. In the DC system, the power is obtained by-product of voltage and current. but in the AC system, things are different because of the effect of reactance.

Types of AC powers

1. Real power
2. Reactive power
3. Apparent power

Real power (P)

As clear from name real power or true power that is responsible for energy dissipation in the circuit. the S.I unit is the watt(W). this type of is works in pure resistive loads where current and voltage are in the same phase and varies sinusoidally with each other. So energy dissipation over an AC cycle is true power.

                         P=VIcosΦ

the phase difference Φ in resistive load is 0 so the power=VI watt

Reactive Power(Q)

The power phasor diagram of components like inductors and capacitors is divided into four quarters. In two-quarters energy is stored and for two-quarters energy is released, due to this, the total power over a complete cycle is zero. Inductor stores energy in the form of magnetic flux and the capacitor stores energy in the form of an electric field. also, the phase difference between current and voltage is π/2.

                       

                        P=VIcosΦ

                        P=0

this means both inductor and capacitor consumes 0 real energy. But Inductors and Capacitors are not pure and to calculate the power we use Reactive power.

                        Q=VIsinΦ

The unit of reactive power is Var(volt-ampere reactive)

Complex Power(S)

I reality both real and reactive power have their combined role in the AC system. so complex power is the sum of real power and imaginary reactive power.

                            

                        S=P+jQ

Apparent power(|S|)

The exact value of the complex value or the magnitude of complex value is called Apparent power. the unit of apparent power in VA. both Var and VA are not approved S.I unit.

                        |S|= √P^2+Q^2