Electrical Engineering ⇒ Topic : By Phasor Algebra

By Phasor Algebra

In this method, voltages, currents and impedances are expressed in the complex form i.e. either in the rectangular or polar form. Since complex form includes both magnitude and phase angle, the solution of parallel-circuit problems can be obtained mathematically by using the rules of phasor algebra. This eliminates the need of phasor diagram. Referring back to the parallel circuit shown in Fig. (a), we have,

                                                                    figure (a)

The solution of I can be obtained in the standard form a ± jb by using the rules of phasor algebra.Then it is an easy task to find the magnitude and phase angle of I.

It may be noted that the phase angle of any current is the *conjugate of its impedance angle.This is an important point. The reader is strongly advised to use polar form for multiplication and division of complex quantities. However, for addition and subtraction, rectangular form should be preferred.