In this article we are going to explain complex power, complex power is known as the sum of real power and reactive power.

 In other words, complex power is also called the representation of electrical power in the form of a complex number, which consists of the real and imaginary parts of power. The real power is called the action at the circuit and the imaginary power is the reactive power.

Power triangle

Power triangle
Power triangle
  • The significance of complex power starts at the power triangle, the power triangle can be easily constructed if the value of complex power is known.
  • Q will be represented with perpendicular portion, P with the base of the triangle, and S will represent with hypodense of power triangle.
  • The real power part gives the active power value and the imaginary power part gives us the reactive power value.
  • Apparent power = √P2 + Q2

Complex power formulas

  • The complex power formula will be the same as the normal power formula

S= P+jQ or S = VI

Apparent Power = √ (True power2 + Reactive Power2)

  • The complex power will be change with the load used with the circuit

At capacitive load, the complex formula will be like,

Z = R- jXC

I = Ip + jIQ

S = P-j Q

At inductive load, the complex power formula will be like,

Z = R + j XL

S = P + j Q


Complex power unit

The unit of complex power is kVAR or kilovolt amp, which is from S= P+Jq


Complex power equation

                                               S = √P2 + Q2 <Tan -1 (Q/P)

P = active power

Q = reactive power


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