Phasor

A phasor is a complex number that represents a sinusoidal function whose amplitude (magnitude), angular frequency, and initial phase are time-invariant.

The common example can be thought of in the context of Laplace Transforms, where a sinusoidal signal can be represented as a rotating vector in the complex plane. The projection of this vector onto the real axis gives the instantaneous value of the sinusoidal function.

Usually represented in the form:

$$P=A{e}^{j(\omega t+\varphi )}$$

Where:

• $A$ is the amplitude of the sinusoid.
• $\omega$ is the angular frequency (in radians per second).
• $\varphi$ is the phase angle (in radians).
• $j$ or $i$ is the imaginary unit.