Best slides for Power Factor, the ppt containing best examples which makes the concept easy to understand and descriptive video is also attached.

1. Power Factor
Generation of DC
Generation of AC
Resistive Load with AC
Capacitive Load with AC
Different value of PF
Conclusion
Inductive Load with AC
ф
P=V I Cos ф

2. Power Factor
Generation of DC
Generation of AC
Resistive Load with AC
Capacitive Load with AC
Different value of PF
Conclusion
Inductive Load with AC
• Most popular method to generate Direct Current (DC) is by using a Photo voltaic cell (solar cell).
• Solar cell is similar in construction with PN diode but it has large x section then the length.

3. Power Factor
Generation of DC
Generation of AC
Different value of PF
Conclusion
• When sun light falls on N-Layer its majority charge carrier i.e. electrons get excited and feels
attraction from P-layer, crosses the junction and comes in to the P-layer.
• Due to the change in electron concentration in P-Layer and N-layer, potential difference appears
across cell.
Resistive Load with AC
Capacitive Load with AC
Inductive Load with AC

4. Power Factor
Generation of DC
Generation of AC
Different value of PF
Conclusion
• This potential difference i.e. voltage always has same polarity i.e “Positive potential” at N-side and
“Negative potential” at P-side and almost of constant magnitude as sunlight cannot vary suddenly and
this voltage is said to be “Direct Voltage”.
• When electric load for example a bulb is connected across the cell an electric current of same nature
as voltage flows through the load and the current is said to be “Direct Current”
Resistive Load with AC
Capacitive Load with AC
Inductive Load with AC

5. Power Factor
Generation of DC
Generation of AC
Different value of PF
Conclusion
• Wave form of Direct Voltage and Direct Current is shown in fig.
• In case of DC, the voltage and current never changes its direction although magnitude can vary (not
sudden)
P = V I P = I2 Ror or
DC source and Resistive Load
Resistive Load with AC
Capacitive Load with AC
Inductive Load with AC

6. Power Factor
Generation of DC
Generation of AC
Different value of PF
Conclusion
• Although Solar cells are getting popular these days, but still maximum part of world’s electrical energy
produced through alternating current generators (Alternators).
• Alternators uses very common phenomenon to produce electric voltage i.e by moving a magnetic
field against stationary electrical conductor (in form of multi-turn winding). Thus the voltage
produced varies in sinusoidal fashion
Generation of Alternating Voltage Waveform of Alternating voltage
Resistive Load with AC
Capacitive Load with AC
Inductive Load with AC

7. Power Factor
Generation of DC
Generation of AC
Resistive Load with AC
Capacitive Load
Different value of PF
Conclusion
Inductive Load with AC
• Although Solar cells are getting popular these days, but still maximum part of world’s electrical energy
produced through alternating current generators (Alternators).
• Alternators uses very common phenomenon to produce electric voltage i.e by moving a magnetic
field against stationary electrical conductor (in form of multi-turn winding). Thus the voltage
produced varies in sinusoidal fashion
DC source and Resistive Load

8. Power Factor
Generation of DC
Generation of AC
Resistive Load with AC
Different value of PF
Conclusion
• When an alternating voltage (waveform shown in blue color fig 2) is applied across an electrical load
of pure resistive nature (symbolically represented in fig 1) such as electric bulb or electric iron etc.
Then, current will have the same nature (waveform shown in red color fig 2).
• There is no phase difference between Voltage and Current as both attend Positive, negative and zero
value at same time i.e. both the oscillating quantities, oscillate in same phase and power always
attend positive value which signifies
AC source and Resistive load
Power, Voltage and Current waveform for Resistive load
Capacitive Load with AC
Inductive Load with AC

9. Power Factor
Generation of DC
Generation of AC
Different value of PF
Conclusion
• Practically many electrical loads comprise of slight inductive nature due to presence of winding or
coils: like electrical fan, tube light with chock coil, washing machine and most of the industrial
equipments.
• In case of inductive load; current lags in phase with voltage due to which average useful power is less
as compare to if it would be only resistive load. Due to, some part of power get returned as can be
seen form waveform (yellow color).
AC source and Resistive-Capacitive (RC) load
Voltage and Current waveform for Resistive-Capacitive (RC) load
Resistive Load with AC
Capacitive Load with AC
Inductive Load with AC

10. Power Factor
Generation of DC
Generation of AC
Different value of PF
Conclusion
• Few special loads can posses capacitive nature due to presence of parallel plates, due to capacitance
the load oppose change in voltage and hence voltage lags behind current in phase.
• Again due to phase difference the average power decreases. As, a part of it get returned which can be
seen from waveform (yellow color)
AC source and Resistive load
Voltage and Current waveform for Resistive load
Resistive Load with AC
Capacitive Load with AC
Inductive Load with AC

11. Power Factor
Generation of DC
Generation of AC
Different value of PF
Conclusion
Resistive Load with AC
Capacitive Load with AC
Inductive Load with AC
Resistive load
Voltage and current In
same phase
Ɵ = 0°
P = V I cos 0°
P = V I
Inductive Load
Current Lags Voltage
by 90°
Ɵ = 90° (lagging)
P = V I cos 90°
P = 0
Capacitive
load
Current lead Voltage
by 90°
Ɵ = 90° (lead)
P = V I cos 90°
P = 0

12. Power Factor
Generation of DC
Generation of AC
Different value of PF
Conclusion
Resistive Load with AC
Capacitive Load with AC
Inductive Load with AC
Resistive-Inductive
Load (R-L Load)
Current lags
voltage by angle Ɵ
0° < Ɵ < 90°
P = V I cos Ɵ
Resistive-Capacitive
Load (R-C Load)
Current lead
voltage by angle Ɵ
0° < Ɵ < 90°
P = V I cos Ɵ