Gandhinagar Institute Of Technology

Topic : Analysis of Phasor Diagram Guided By :

Branch : Batch :

MR. RAHISH SIR

Active Learning Assignment

Electrical F1

Elements Of Electrical Engineering (2110005)

Name ENROLLMENT NO. Abhishek Chokshi 140120109005 Raj Shah Adnan Vohra

PREPARED BY:-

140120109054140120109063

Series R-C circuit

Circuit contain a pure resistance R ohms connected in series with pure capacitor C farads.

It is known as R-C circuit.

Voltage across resistance V=IR.

Voltage across capacitor V=IC.

Vr remain in same phase.Vc lag behind current

6

Kirchhoff’s voltage law:

Or;

0 CR VVEV

CR VVE

R-C

in such circuits the voltage across each of the components is the same and it is the currents that are of interest

Phasor analysis of parallel circuits

Phasor analysis of an RC circuit

Series R-L circuit

Circuit contains a pure resistance R ohms connected in series with a pure inductance L henry .

It known as R-L circuit

Phasor analysis of an RL circuit

Voltage across resistor :V=IR.

Voltage across inductor:V=IL.

Vr is in same phase.Vl leads by 90’.

From the phasor diagram it is clear that that the magnitude of the voltage across the arrangement V is

where Z is the magnitude of the impedance, so Z =|Z|

IZXRI

IXIR

VVV

L

L

LR

22

22

22

)()(

22LXRZ

In this case ,when only inductor current leads the voltage by 90’.

But when we combine Resistance and inductance the phase angle is between 0’ to 90’.

Phasor diagram:

Series R-L-C circuit

Circuit which contains a pure resistance of R ohms.

A pure inductor of L henry.A pure capacitor of capacitance C farads.

It is known as R-L-C series circuit.

Voltage drop across resistance:Vr=IR in phase with current I.

Voltage drop across inductance:VL=IXL leadin by 90 ‘

Voltage drop across capacitance:Vc=Ixc lagging behind by 90’.

Phasor analysis of an RLC circuit

Three possible cases: (1)VL >VC that is XL>XC:

According to case(1):

The phase angle is positive .

Behave as R-L circuit.Current lag behind voltage Power factor is lagging

According to case(2):Phase angle is negative.Behave as a R-C circuit.Current leads the voltage.Power factor is leading.

According to case(3):Phase angle is zero.Circuit is purely resistive circuit.

Current is in phase with applied voltage.

Power factor is unity.

Thank You