Docsity
Docsity
Prepare for your exams
Prepare for your exams

Study with the several resources on Docsity

Earn points to download
Earn points to download

Earn points by helping other students or get them with a premium plan

Guidelines and tips
Guidelines and tips
Sell on Docsity
Sell on Docsity
Docsity AI
Docsity AI
Log inSign up

Prepare for your exams

Study with the several resources on Docsity

Find documents

Prepare for your exams with the study notes shared by other students like you on Docsity

Search for your university

Find the specific documents for your university's exams

Docsity AINEW

Summarize your documents, ask them questions, convert them into quizzes and concept maps

Explore questions

Clear up your doubts by reading the answers to questions asked by your fellow students

Earn points to download

Earn points by helping other students or get them with a premium plan

Share documents
download point icon20 Points

For each uploaded document

Answer questions
download point icon5 Points

For each given answer (max 1 per day)

All the ways to get free points
Get points immediately

Choose a premium plan with all the points you need

Study Opportunities

Choose your next study program

Get in touch with the best universities in the world. Search through thousands of universities and official partners

Community

Ask the community

Ask the community for help and clear up your study doubts

Free resources

Our save-the-student-ebooks!

Download our free guides on studying techniques, anxiety management strategies, and thesis advice from Docsity tutors

Three Phase Rectifier-Power Electronics-Assignment, Exercises of Power Electronics

Bengal Engineering & Science UniversityPower Electronics

This assignment was assigned by Prof. Asad Mirza at Bengal Engineering and Science University for Power Electronics course. It includes: Power, Electronics, Full-Wave, Rectifier, Circuit, Transformer, Leakage, Inductance, Commutation, Interval, Input

Typology: Exercises

2011/2012

Uploaded on 07/23/2012

gangadatt
gangadatt 🇮🇳

3.2

(9)

71 documents

1 / 4

Toggle sidebar

This page cannot be seen from the preview

Don't miss anything!

bg1
EE 4303 – POWER ELECTRONICS
2nd Assignment
Problem 1:
Consider the full-wave rectifier circuit shown in the attached figure. The 50H inductors are
representing line inductance due to transformer leakage and cables. The converter is
operating with a firing delay angle
45
. Determine:
a. The average output voltage o
vwith zero line
inductance;
b. The load current value in amperes;
c. The commutation interval in s;
d. Plot the output voltage, o
vwith 50H line
inductance;
e. Determine the new value of average output
voltage o
vwith 50H line inductance;
f. Determine the output power
g. Accurately plot the current through the two thyristors.
Problem 2
For a three-phase full-bridge rectifier using six thyristors, the input voltages are specified as

tva
cos100,
120cos100 tvb
and
120cos100 tva
a. Determine the firing sequence of the thyristors.
b. For a firing delay angle =30o, plot gate pulses for thyristor T1.
c. Plot the current through T4.
d. Plot the voltage across T4.
e. Plot the output voltage.
f. Plot the voltage across 100mH load inductor.
g. Determine the peak and average current in T4.
h. Determine the rms value of line current.
i. Determine the real input power (Watts).
j. Determine the apparent input power (VA).
k. Determine the power factor.
vo
V1=220VRMS
100 mH
2 ohm
V2=220VRMS
+
+Line
Inductance
50 microH
Line
Inductance
50 microH
docsity.com
pf3
pf4

Partial preview of the text

Download Three Phase Rectifier-Power Electronics-Assignment and more Exercises Power Electronics in PDF only on Docsity!

EE 4303 – POWER ELECTRONICS

2 nd^ Assignment

Problem 1:

Consider the full-wave rectifier circuit shown in the attached figure. The 50H inductors are representing line inductance due to transformer leakage and cables. The converter is

operating with a firing delay angle   45 . Determine:

a. The average output voltage vo with zero line inductance; b. The load current value in amperes; c. The commutation interval in s; d. Plot the output voltage, vo with 50H line inductance; e. Determine the new value of average output voltage vo with 50H line inductance; f. Determine the output power g. Accurately plot the current through the two thyristors.

Problem 2

For a three-phase full-bridge rectifier using six thyristors, the input voltages are specified as

v a  100 cos   t , vb  100 cos  t  120 and v a  100 cos  t  120 

a. Determine the firing sequence of the thyristors. b. For a firing delay angle =30o^ , plot gate pulses for thyristor T1. c. Plot the current through T4. d. Plot the voltage across T4. e. Plot the output voltage. f. Plot the voltage across 100mH load inductor. g. Determine the peak and average current in T4. h. Determine the rms value of line current. i. Determine the real input power (Watts). j. Determine the apparent input power (VA). k. Determine the power factor.

v^ o

V 1 =220VRMS

100 mH

2 ohm

V 2 =220VRMS

  • Line Inductance 50 microH

Line Inductance 50 microH

Problem 3:

( a ) Consider the diode bridge shown in the adjacent figure. The DC sources in series with the diodes are used to model the forward voltage drop of the diode. Plot the load resistor ‘R’ voltage waveform. Determine the rms of this resistor voltage.

(b) The same diode bridge is feeding a 3V DC source and a resistive load. All resistors are in ohms. Plot the resistor voltage waveform. Determine the power delivered to the 3V source.

Problem 4:

The waveform shown on the right is typical line current in a three-phase diode rectifier bridge.

  1. Determine the RMS value of the current
  2. Determine the THD of this waveform.
  3. Determine the average input power if the input phase voltage is 100 cos ( t ) (in phase with the current).
  4. Determine the rectifier input power factor.

Problem 5:

Compute the load regulation for the dc/dc converter operating at 20 kHz, shown in the adjacent figure; given that the load resistance can vary from open (∞) to 50 For this calculation, use 100V input voltage. The duty ratio is fixed at D = 0.5 for all cases. Also determine line regulation with Rs = 0 and given that Vin can vary between 90 to 100V. Neglect the ripple in the output voltage.

100μH

100 μF 90 50 to 100V

Rs=

disadvantage of PWM method compared with fundamental frequency switching VSI.

Problem 9:

a. Draw complete power circuit of a voltage sourced, three-phase PWM bridge inverter using IGBT switches. Include any diodes that may be required. b. What is the purpose of the reverse parallel diodes usually included in the same package with the IGBT? c. What are the constraints on the switching functions for the two switches forming a phase- leg? Plot the switching functions of the two switches in a phase leg. d. How many states this three-phase inverter bridge may be placed in? e. Graphically draw these possible switching states as phasors. f. At a specific instant in time, the inverter is to synthesize a voltage phasor described by the triplet ( Va = 0.2; Vb = 0.2 and Vc = -0.4). Determine the two switching states that the inverter must be placed into and the respective switching times ( T 1, T 2, T 0) for synthesizing this voltage. The switching frequency is 10kHz. Draw the actual switching functions for the phase legs.