power electronics lab manual_with_cover

L A B M A N U A L

Power Electronics Lab Manual Version 1.0 – 11 November 2014

Preliminary Content – This document may not include the latest updates and may

contain errors.

Power Electronics Lab Manual This introductory lab series was

created in collaboration with Dr. Afshin Izadian of the Indiana University – Purdue University Indianapolis. It introduces students to basic power electronics circuits and the analysis techniques used to characterize them.

Power Electronics Lab Manual 2

Worldwide Technical Support and Product Information ni.com

National Instruments Corporate Headquarters

11500 N Mopac Expwy Austin, Texas 78759-3504 USA Tel: 512 683 0100

Worldwide Offices

Visit ni.com/global for the latest contact information.

Andean and Caribbean +58 212 503-5310, Argentina 0800 666 0037, Australia 1800 300 800, Austria 43 662 45 79 90 0, Belgium 32 0 2 757 00 20, Brazil 55 11 3262 3599, Canada 800 433 3488, Chile 800 532 951, China 86 21 5050 9800, Czech Republic/Slovakia 420 224 235 774, Denmark 45 45 76 26 00, Finland 358 0 9 725 725 11, France 33 0 1 48 14 24 24, Germany 49 89 741 31 30, Hungary 36 23 501 580, India 1 800 425 7070, Ireland 353 0 1867 4374, Israel 972 3 6393737, Italy 39 02 413091, Japan 81 3 5472 2970, Korea 82 02 3451 3400, Lebanon 961 0 1 33 28 28, Malaysia 1800 887710, Mexico 01 800 010 0793, Netherlands 31 0 348 433 466, New Zealand 0800 553 322, Norway 47 0 66 90 76 60, Poland 48 22 3390150, Portugal 351 210 311 210, Russia 7 495 783 68 51, Singapore 1800 226 5886, Slovenia/Croatia, Bosnia/Herzegovina, Serbia/Montenegro, Macedonia 386 3 425 42 00, South Africa 27 0 11 805 8197, Spain 34 91 640 0085, Sweden 46 0 8 587 895 00, Switzerland 41 56 200 51 51, Taiwan 886 2 2377 2222, Thailand 662 278 6777, Turkey 90 212 279 3031, U.K. 44 0 1635 523545, Uruguay 0004 055 114

© 2014 National Instruments. All rights reserved.

Important Information

Warranty

The media on which you receive National Instruments software are warranted not to fail to execute programming instructions, due to defects in materials and workmanship, for a period of 90 days from date of shipment, as evidenced by receipts or other documentation. National Instruments will, at its option, repair or replace software media that do not execute programming instructions if National Instruments receives notice of such defects during the warranty period. National Instruments does not warrant that the operation of the software shall be uninterrupted or error free. A Return Material Authorization (RMA) number must be obtained from the factory and clearly marked on the outside of the package before any equipment will be accepted for warranty work. National Instruments will pay the shipping costs of returning to the owner parts, which are covered by warranty. National Instruments believes that the information in this document is accurate. The document has been carefully reviewed for technical accuracy. In the event that technical or typographical errors exist, National Instruments reserves the right to make changes to subsequent editions of this document without prior notice to holders of this edition. The reader should consult National Instruments if errors are suspected. In no event shall National Instruments be liable for any damages arising out of or related to this document or the information contained in it. EXCEPT AS SPECIFIED HEREIN, NATIONAL INSTRUMENTS MAKES NO WARRANTIES, EXPRESS OR IMPLIED, AND SPECIFICALLY DISCLAIMS ANY WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. CUSTOMER’S RIGHT TO RECOVER DAMAGES CAUSED

BY FAULT OR NEGLIGENCE ON THE PART OF NATIONAL INSTRUMENTS SHALL BE LIMITED TO THE AMOUNT THERETOFORE PAID BY THE CUSTOMER. NATIONAL INSTRUMENTS WILL NOT BE LIABLE FOR DAMAGES RESULTING FROM LOSS OF DATA, PROFITS, USE OF PRODUCTS, OR INCIDENTAL OR CONSEQUENTIAL DAMAGES, EVEN IF ADVISED OF THE POSSIBILITY THEREOF. This limitation of the liability of National

Instruments will apply regardless of the form of action, whether in contract or tort, including negligence. Any action against National Instruments must be brought within one year after the cause of action accrues. National Instruments shall not be liable for any delay in performance due to causes beyond its reasonable control. The warranty provided herein does not cover damages, defects, malfunctions, or service failures caused by owner’s failure to follow the National Instruments installation, operation, or maintenance instructions; owner’s modification of the product; owner’s abuse, misuse, or negligent acts; and power failure or surges, fire, flood, accident, actions of third parties, or other events outside reasonable control.


Copyright

Under the copyright laws, this publication may not be reproduced or transmitted in any form, electronic or mechanical, including photocopying, recording, storing in an information retrieval system, or translating, in whole or in part, without the prior written consent of National Instruments Corporation. National Instruments respects the intellectual property of others, and we ask our users to do the same. NI software is protected by copyright and other intellectual property laws. Where NI software may be used to reproduce software or other materials belonging to others, you may use NI software only to reproduce materials that you may reproduce in accordance with the terms of any applicable license or other legal restriction.

Trademarks

LabVIEW, National Instruments, NI, ni.com, and NI-DAQ are trademarks of National Instruments. Refer to the Terms of Use section on ni.com/legal for more information about National Instruments trademarks. Other product and company names mentioned herein are trademarks or trade names of their respective companies

Patents

For patents covering National Instruments products, refer to ni.com/patents.

Some portions of this product are protected under United States Patent No. 6,560,572.

WARNING REGARDING USE OF NATIONAL INSTRUMENTS PRODUCTS

(1) NATIONAL INSTRUMENTS PRODUCTS ARE NOT DESIGNED WITH COMPONENTS AND TESTING FOR A LEVEL OF RELIABILITY SUITABLE FOR USE IN OR IN CONNECTION WITH SURGICAL IMPLANTS OR AS CRITICAL COMPONENTS IN ANY LIFE SUPPORT SYSTEMS WHOSE FAILURE TO PERFORM CAN REASONABLY BE EXPECTED TO CAUSE SIGNIFICANT INJURY TO A HUMAN.

(2) IN ANY APPLICATION, INCLUDING THE ABOVE, RELIABILITY OF OPERATION OF THE SOFTWARE PRODUCTS CAN BE IMPAIRED BY ADVERSE FACTORS, INCLUDING BUT NOT LIMITED TO FLUCTUATIONS IN ELECTRICAL POWER SUPPLY, COMPUTER HARDWARE MALFUNCTIONS, COMPUTER OPERATING SYSTEM SOFTWARE FITNESS, FITNESS OF COMPILERS AND DEVELOPMENT SOFTWARE USED TO DEVELOP AN APPLICATION, INSTALLATION ERRORS, SOFTWARE AND HARDWARE COMPATIBILITY PROBLEMS, MALFUNCTIONS OR FAILURES OF ELECTRONIC MONITORING OR CONTROL DEVICES, TRANSIENT FAILURES OF ELECTRONIC SYSTEMS (HARDWARE AND/OR SOFTWARE), UNANTICIPATED USES OR MISUSES, OR ERRORS ON THE PART OF THE USER OR APPLICATIONS DESIGNER (ADVERSE FACTORS SUCH AS THESE ARE HEREAFTER COLLECTIVELY TERMED “SYSTEM FAILURES”). ANY APPLICATION WHERE A SYSTEM FAILURE WOULD CREATE A RISK OF HARM TO PROPERTY OR PERSONS (INCLUDING THE RISK OF BODILY INJURY AND DEATH) SHOULD NOT BE RELIANT SOLELY UPON ONE FORM OF ELECTRONIC SYSTEM DUE TO THE RISK OF SYSTEM FAILURE. TO AVOID DAMAGE, INJURY, OR DEATH, THE USER OR APPLICATION DESIGNER MUST TAKE REASONABLY PRUDENT STEPS TO PROTECT AGAINST SYSTEM FAILURES, INCLUDING BUT NOT LIMITED TO BACK-UP OR SHUT DOWN MECHANISMS. BECAUSE EACH END-USER SYSTEM IS CUSTOMIZED AND DIFFERS FROM NATIONAL INSTRUMENTS' TESTING PLATFORMS AND BECAUSE A USER OR APPLICATION DESIGNER MAY USE NATIONAL INSTRUMENTS PRODUCTS IN COMBINATION WITH OTHER PRODUCTS IN A MANNER NOT EVALUATED OR CONTEMPLATED BY NATIONAL INSTRUMENTS, THE USER OR APPLICATION DESIGNER IS ULTIMATELY RESPONSIBLE FOR VERIFYING AND VALIDATING THE SUITABILITY OF NATIONAL INSTRUMENTS PRODUCTS WHENEVER NATIONAL INSTRUMENTS PRODUCTS ARE INCORPORATED IN A SYSTEM OR APPLICATION, INCLUDING, WITHOUT LIMITATION, THE APPROPRIATE DESIGN, PROCESS AND SAFETY LEVEL OF SUCH SYSTEM OR APPLICATION.


Contents Lab at a Glance .................................................................................................................... 7

What You Will Do ................................................................................................................ 7

Time Required ..................................................................................................................... 7

Background Knowledge ....................................................................................................... 8

Gate Driver Lab ........................................................................................................................ 9

1.1 Goal ............................................................................................................................. 10

1.2 Objectives .................................................................................................................... 10

1.3 Pre-Lab Activities .......................................................................................................... 10

1.3a Get to Know the Topics ........................................................................................................................ 10

1.3b Pre-Assessment Quiz ............................................................................................................................ 11

1.4 Lab Procedure ............................................................................................................... 12

1.4a Design the Circuit in Multisim .............................................................................................................. 12

1.4b Perform an Oscilloscope Analysis ......................................................................................................... 13

1.4c Simulate a Power Transistor with Gate Drive ....................................................................................... 14

1.4d Build the Gate Driver Circuit on a myProto Breadboard ....................................................................... 16

1.5 Create a Lab Report ....................................................................................................... 17

1.6 Final Observations ........................................................................................................ 17

Buck Converter Lab ................................................................................................................. 19

2.1 Goal ............................................................................................................................. 20

2.2 Objectives .................................................................................................................... 20



2.3b Pre-Assessment Quiz ........................................................................................................................... 21

2.4 Lab Procedure ............................................................................................................... 21


2.4b Perform a Transient Analysis ............................................................................................................... 22

2.4c Perform a Parameter Sweep (Resistive Load) ...................................................................................... 24

2.4d Perform a Parameter Sweep (Corner Frequency) ................................................................................ 26

2.4e Perform a Parameter Sweep (Inductive Load) ......................................................................................27

2.4f Build and Explore the Buck Converter on a myProto Breadboard ..........................................................27


2.5 Create a Lab Report ...................................................................................................... 29

2.6 Final Observations ....................................................................................................... 29

Boost Converter Lab ............................................................................................................... 31

3.1 Goal ............................................................................................................................. 32

3.2 Objectives .................................................................................................................... 32




3.4 Lab Procedure ............................................................................................................... 33

3.4a Design the Circuit in Multisim ............................................................................................................... 33



3.4d Perform a Parameter Sweep (Corner Frequency)................................................................................. 38

3.4e Perform a Parameter Sweep (Inductive Load) ..................................................................................... 39

3.4f Build and Explore the Boost Converter on a myProto Breadboard ........................................................ 39



Buck Boost Converter Lab ....................................................................................................... 43

4.1 Goal ............................................................................................................................ 44

4.2 Objectives ................................................................................................................... 44

4.3 Pre-Lab Activities ......................................................................................................... 44


4.3b Pre-Assessment Quiz ........................................................................................................................... 45

4.4 Lab Procedure............................................................................................................... 45




4.4d Perform a Parameter Sweep (Corner Frequency) ................................................................................ 50

4.4e Perform a Parameter Sweep (Inductive Load) ...................................................................................... 51

4.4f Build and Explore the Buck Boost Converter on a myProto Breadboard ................................................ 51

4.5 Create a Lab Report ....................................................................................................... 52



Full Bridge Inverter Lab .......................................................................................................... 55

5.1 Goal .............................................................................................................................56

5.2 Objectives ....................................................................................................................56

5.3 Pre-Lab Activities ..........................................................................................................56



5.4 Lab Procedures ............................................................................................................ 58

5.4a Design a Multisim Circuit ..................................................................................................................... 58


5.4c Perform a Parameter Sweep ................................................................................................................ 61

5.4d Build the Full Bridge Inverter on a myProto Breadboard ...................................................................... 62

5.5 Lab Report ....................................................................................................................63

5.6 Final Observations ........................................................................................................63

Rectifier Lab ........................................................................................................................... 65

6.1 Goal ............................................................................................................................ 66

6.2 Objectives ................................................................................................................... 66

6.3 Pre-Lab Activities ......................................................................................................... 66


6.3b Pre-Assessment Quiz........................................................................................................................... 67

6.4 Lab Procedure Part 1: Half and Full Wave Uncontrolled Rectifiers ......................................67



6.4c Perform a Parameter Sweep (Half Wave Rectifier) ...............................................................................70

6.4d Perform a Parameter Sweep (Full Wave Rectifier) ................................................................................72

6.4e Build and Explore the Uncontrolled Rectifier on a myProto Breadboard ............................................... 73

6.5 Lab Procedure Part 2: Phase Controlled Full Bridge Rectifier ............................................. 74

6.5a Multisim SCR Simulation ..................................................................................................................... 74

6.5b SCR Transient analysis ......................................................................................................................... 75


6.7 Final Observations ........................................................................................................76


Lab at a Glance

What You Will Do Throughout these labs you will use NI myDAQ and LabVIEW and Multisim to simulate and test basic

Power Electronics circuits. These labs will allow students to quickly see the differences between ideal

and real circuits. Students will learn the importance of the additional circuitry needed to drive power

transistors as well as how to test various component values on these circuits to decide how to optimize

the output.

Time Required The labs should take around three (2-3) hours, but this can vary depending on your prior knowledge and

rate of learning.

Lab Overview

Gate Driver Discover power transistors and the importance of the gate driver

circuit

Buck Converter Simulate, build and experiment with a DC-DC step down

converter

Boost Converter Simulate, build and experiment with a DC-DC step up converter

Buck Boost Converter Simulate, build and experiment with a DC-DC step up and step

down converter

Full Bridge Inverter Simulate, build and experiment with a DC – AC converter

Rectifier Simulate, build and experiment with a Half, Full bridge and

controlled rectifier


Background Knowledge It is recommended that you have some exposure to LabVIEW, but it is not required. The instructions for

the exercises cover all necessary steps to complete the task. Note that you are expected to learn basic

tasks as you progress, and the instructions become less detailed and require that you retain some of the

knowledge.

You are expected to be familiar with using a computer, mouse, and keyboard.


L A B 1

Gate Driver Lab One Hour


1.1 Goal To understand the importance of using a gate driver when controlling power transistors and to become

familiar with National Instruments hardware

1.2 Objectives In this lab you will:

Simulate a circuit in Multisim software.

Build and interact with a gate driver circuit. You will design the circuit to sweep various

frequencies of square waves to output to an insulated Gate Bipolar Transistor (IGBT).

Create a lab report to present your data, observations, and conclusions.

1.3 Pre-Lab Activities

1.3a Get to Know the Topics

Review the following resources to familiarize yourself with the topics listed before you begin

the lab:

Textbook References:

Hart, Daniel W. Power Electronics. New York, NY: McGraw-Hill, 2011. Section: 10.

Mohan, Ned, Undeland, Tore M, Robbins, William P. Power Electronics: Converters Applications and Design. Danvers, MA: John Wiley and Sons, 2003. Sections: 28.1 – 28.3

myDAQ References:

Get Started Using NI myDAQ with LabVIEW for Education

https://www.youtube.com/watch?v=RsD2tHbuAF4

DAQ Lesson 1 https://decibel.ni.com/content/docs/DOC-11624


https://decibel.ni.com/content/docs/DOC-11624


1.3b Pre-Assessment Quiz

Complete the following quiz to check your understanding of the relevant topics before you

begin the lab.

a. What is meant when a circuit is Unipolar or Bipolar? List the benefits of each.

b. Draw a MOSFET front view and label each of the following parts:

a) Gate – Metal

b) Gate – Oxide

c) Drain

d) Source

e) Body

b. Explain how the MOS capacitor contributes to the need for gate drive circuitry in 3-5

sentences. Include information on charging and discharging capacitors and suggest

different ways to charge and discharge at different rates.

c. Draw and label a transistor with a gate drive circuit. Draw the path for current to and from

the gate when the control circuit produces a high and another when the control circuit

produces a low.

d. List the different regions of operation for a BJT and MOSFET. Using the data sheet for your

Insulated Gate Bipolar Transistor (IGBT), list the voltages needed to put the transistor into

its different regions.

e. What are the voltage and current specifications of the analog output channels of the

myDAQ? What region of operation do you estimate the myDAQ can drive the IGBT into

without a drive circuit?


1.4 Lab Procedure

1.4a Design the Circuit in Multisim

Designing the circuit in Multisim allows you to gain an understanding of the circuit you will

prototype on a breadboard later.

Simulate a Power Transistor with No Gate Drive

Step 1: Design the following circuit in Multisim

Figure 1 Transistor Circuit with No Gate Drive

Finding Components in Multisim

V1/V2 – DC voltage sources, V2 is being used as a reference voltage for the PWM signal being

generated while V1 is the voltage source of the switching circuit. Found in Group: Sources;

Family: Power_Sources.

U1 – PWM function used to generate the square wave signal for the transistor, found in Group:

Power; Family: Power_Controllers.

IRF520 – Power transistor used to switch the DC supply based on the square wave signal from

the PWM function. Found in Group: Transistors; Family: Power_Mos_N.


XSC1 – Oscilloscope used to monitor runtime signals from the circuit.

You can use wires or on-page connectors to wire up the circuit.

For more information about working in Multisim, visit:

https://www.youtube.com/user/ntspress/search?query=multisim.

1.4b Perform an Oscilloscope Analysis

An oscilloscope allows you to probe different portions of your circuit and gain an

understanding of the inputs and outputs of your circuit during simulation runtime. You will

observe the output of an IGBT as you apply higher frequency square waves to the input.

Step 2: Double click on the PWM function and enter the following configuration settings:

Reference signal frequency: 250 kHz

Reference Signal minimum voltage: 0V

Reference Signal maximum voltage: 1V

Output voltage amplitude: 5V

Output rise/fall time: 1ns

This will allow the PWM function to output a signal based on the comparison between the

input voltage provided by “V2” and the sawtooth wave used as a reference. The function will

output a high when the input voltage is higher than the reference and a low when it is lower.

Since the input is a constant, the output signal will maintain a constant ratio between time

spent high and low. The input voltage is set to 0.5 which makes it so that it is high higher than

the reference sawtooth voltage (set to 1V) for half the time. This ratio will remain the same

even as the frequency of the sawtooth reference signal is changed.

Click “Ok” to accept the settings you entered.

Step 3: Double Click on the Oscilloscope function to open the graph panel as seen in Figure 2.

Click on the green arrow in the main Multisim window to let the simulation run for a few

seconds, and then stop it by pressing on the red stop square in the main Multisim window. On

the Oscilloscope panel, increase the Timebase: Scale field to 100ns/Div and use the scroll bar

to move to a point on the graph where there is a rising edge for Signal A.


Note: You will need to change the Scale of channel A and B in order to see all of the signals

you are simulating.

Figure 2 Oscilloscope graph panel

Step 4: Move cursor T2, using the left and right arrow buttons, to the point on signal A that is

approximately 90% of signal A’s maximum amplitude. Move cursor T1 to approximately the

10% point. Record the time for T2-T1 as “Rise Time” and take a screen shot of the graph for

your lab report.

Note: The cursor controls are right below the scroll bar on the oscilloscope panel.

Step 5: Using the scroll bar again, move to a location where there is a falling edge of signal A

and repeat the process you followed from step 4, this time with T2 being the 10% point and T1

being the 90% point. Record the time for T2-T1 as “Fall Time” and take a screen shot for your

lab report.

Step 6: Change the Timebase: Scale in order to see multiple periods of signal A. Take a screen

shot of this for your lab report and record the maximum amplitude of signal A.

1.4c Simulate a Power Transistor with Gate Drive

Step 7: Modify your current circuit to match the following.


The additional components can be found in Group: Transistors: Family: BJT_NPN and BJT_PNP.

You can search for them by the model numbers listed in the figure. The additional power

supply provides a higher voltage and current signal that can be switched by the control signal.

Figure 3 Create Measurement Expression

Step 8: Repeat steps 3-6 on the new circuit to accumulate information to use for comparison

between the power transistor output with and without the gate driver.

Challenge Question 1: Explain in detail why the output rise and fall times are so different

between the two circuits.

Challenge Question 2: Go back and calculate the power dissipated in the transistor in both

cases. Explain why there is a difference between the two and reference the regions that the

transistor is in.


1.4d Build the Gate Driver Circuit on a myProto Breadboard

The circuit you built in Multisim utilized power transistors in its design, these will be replaced with

Insulated Gate Bipolar Transistors in the breadboard design, and two integrated chips will be used

to provide isolation and gate drive.

Step 9: Using the schematic provided in Figure 4, build the gate driver circuit on a myProto and

wire the appropriate lines from the circuit to the breakout bank of the myProto. Connect the

myProto to the myDAQ, and plug the myDAQ into your computer using the USB connector.

Figure 4 Isolation and gate drive integrated chips

Step 10: Open the Gate Driver Lab.vi, select the appropriate myDAQ from the “Devices” drop

down, and run the VI. Observe the output waveform and comment on the amplitude and rise and

fall times of the signal. Vary the frequency of the output square wave and observe the change in the

output waveform.

Step 11 (Optional): Directly connect the myDAQ control signal to the gate of the IGBT and rerun

the Gate Driver Lab.vi. Vary the signal frequency and examine the output waveform for any

changes. Comment on the influence of the gate driver in your lab report.

Boost Converter Lab 17

1.5 Create a Lab Report Complete a 3-5 page report which includes all pictures, observations and answers to questions

presented in the lab. Label all pictures with descriptive captions that relate them back to content in

your lab report. Include an introduction, conclusion and 3-5 sentences that talk about the effects of

a gate driver on a power circuit. Discuss how the circuit can be improved to allow for less power

dissipation and suggest ways to maintain performance at even higher frequencies.

1.6 Final Observations Record other thoughts and observations you made throughout the lab and connect them to something

you have observed or experienced in the real world.

Challenge: Explore PCB Design

Attached are schematics for the gate driver circuit. These can either be used to add to the lab

experience with an additional PCB design section or help reduce prototyping time for students if

boards are created before the lab by lab assistants.


L A B 2

Buck Converter Lab One Hour


2.1 Goal To understand the basics of a buck converter circuit, common transistors used in power electronics, and

National Instruments hardware


Simulate a buck converter circuit in Multisim software.

Build and interact with a step down, DC to DC converter circuit, commonly known as a buck

converter. You will design the circuit to output a switch DC voltage that varies according to

switch frequency and duty cycle.





the lab.


Hart, Daniel W. Power Electronics. New York, NY: McGraw-Hill 2011. Print Sections: 1.4, 8.1-8.4 Mohan, Ned, Undeland, Tore M, Robbins, William P. Power Electronics: Converters Applications and Design. Danvers, MA: John Wiley and Sons 2003 Sections: 2.1-2.8, 7.2-7.4 myDAQ References: Get Started Using NI myDAQ with LabVIEW for Education

https://www.youtube.com/watch?v=RsD2tHbuAF4 DAQ Lesson 1 https://decibel.ni.com/content/docs/DOC-11624





Complete the following quiz to check your understanding of the relevant topics before you begin the

lab.

a. Create a table that compares at least four transistors and provides a ranking of the

transistors based on power capability and switching speed.

b. Describe at least one method for reducing power loss in your circuit. Explain how the

method can be implemented in a practical application.

c. Draw the two modes of operation for the buck converter. Label the flow of current for each

mode. Write the expression for duty ratio and comment on what makes the duty ratio so

important

d. Write the equation for output voltage ripple for a buck converter. Comment on what this

equation implies about switching frequency and the corner frequency of the low pass filter

in the buck converter.

e. List all the steps and I/O lines needed to generate a continuous pulse train from the

myDAQ using the on-board counter.

2.4 Lab Procedure



prototype on the breadboard later. Note that MOSFET Power transistors are used in the

simulation instead of the IGBTs used in prototyping, and the gate driver circuit from Lab 0

Gate Driver has been purposely removed in order to emphasize the buck converter

configuration.

Design the following circuit in Multisim.


Figure 5 Buck (Step Down) Converter Circuit


DC_Source – DC voltage source found in Group: Sources; Family: Power_Sources.

PWM_Generator – PWM function used to generate the buck converter control signal, found in

Group: Power; Family: Power_Controllers.

DC_PWM_Controller – DC signal used as a reference for the PWM generation. See DC_Source

for location.

VCVS– Voltage Controlled Voltage Source used to provide a constant voltage regardless of the

current requirements of the load, in this case the MOSFET. Found in Group: Sources; Family:

Controlled_Voltage_Sources.

Power_MOSFET Q1– Power transistor used to switch the DC supply in order to provide an

alternating signal for the buck converter. Found in Group: Transistors; Family: Power_Mos_N.


https://www.youtube.com/user/ntspress/search?query=multisim

2.4b Perform a Transient Analysis

A transient analysis gives you an idea of how your circuit will respond over a set period of time.

It allows you to apply some input and observe an output through simulation.


Step 2: Label the wire at the top of the resister branch by right clicking on it and choosing

“Properties”. Then under the “Net name” tab, update “Preferred net name” with a descriptive

name of your choice, and click “Ok”.

Figure 6 Wire Properties

Step 3: Click “Simulate” on the top toolbar and navigate to Analyses>>Transient Analysis. In

the pop up configuration window, choose the “Analysis parameters” tab and set the following

parameters:

Initial Conditions: Set to zero

Start time (TSTART): 0

End time (TSTOP): 0.05s

Step 4: Navigate to the “Output” tab, click on the descriptive name you just made to select

that node to monitor from the “Variables in circuit” field and click “Add”. Select anything that

may be in the “Selected variable for analysis” field that you are not monitoring and click

“Remove”.



Step 5: Click “Simulate” to run the transient analysis. Take a screen shot of your results to

include in your lab report.

2.4c Perform a Parameter Sweep (Resistive Load)

A parameter sweep gives you an idea of how your circuit would respond with different values

for components such as resistors and capacitors. This sweep can be fine-tuned to allow you to

find the optimum point of operation for you circuit, so when you prototype your circuit with

real components you can have an idea of the range of component values you can use to

achieve a satisfactory output. In this lab you will perform parameter sweeps on the control

signal’s duty cycle, the buck converter capacitance, inductance, and load inductance.


Step 6: Click “Simulate” on the top toolbar and navigate to Analyses>> Parameter Sweep. In

the pop up configuration window, navigate to the “Analysis parameters” tab and set the

following parameters:

Sweep Parameter: Device Parameter

Device Type: Vsource

Name: vdc_pwm_controller (the name of the PWM_controller on your schematic)

Parameter: dc

Start: 100 mV

Stop: 950 mV

Number of points: 6

Analysis to sweep: Transient Analysis

Verify on the “Output” tab that the “Selected variables for analysis” field shows the resistor

load branch as selected for analysis, the same that was chosen for your transient analysis step.

Click “Simulate” to run the parameter sweep. This will create six instances of your buck

converter output, which correspond to the six different PWM duty cycles created from varying

the PWM_Controller voltage.

Take a screen shot of your results to include in your lab report. Find out what the PWM

switching frequency is from the PWM generator function (done by double clicking on the

function) and label the screenshot with the frequency where the analysis takes place.

Step 7: Pick five different frequencies evenly spaced out in the range from 50Hz to 20 kHz.

Change the PWM generator frequency to each of these values, and rerun your transient

analysis from steps 2 and 3 for each frequency value. Take a screen shot of all of these trials for

your lab report and comment on the effects you observed of changing the generator

frequency.


2.4d Perform a Parameter Sweep (Corner Frequency)

The corner frequency of your LC (inductor capacitor) lowpass filter can be increased or

decreased to change the high frequency content allowed through your buck converter. Next,

you will explore how you can change the response of the filter and its effects on the buck

converter DC output.

Step 8: Navigate to the “Parameter Sweep” analysis and select the following parameters to

perform a sweep of the inductance:


Device Type: Inductor

Name: L1

Parameter: inductance

Start: 1 mH

Stop: 100 mH

Number of points: 6


Step 9: Click “Simulate” to run the analysis. Take a screen shot of the output for your lab

report and comment on the impact of the inductance in your buck converter. Include in your

comment a theoretical explanation of the inductor and its response to change in voltage and

current.


perform a sweep of the capacitance:


Device Type: Capacitor

Name: C1

Parameter: capacitance

Start: 1 uF

Stop: 200 uF

Number of points: 12




report and comment on the impact of the capacitance in your buck converter. Include in your

comment a theoretical explanation of the capacitor and its response to change in voltage and

current.

2.4e Perform a Parameter Sweep (Inductive Load)

In most applications, your DC-DC converter will not be tied to just a resistor. Most hardware

includes some form of capacitance and inductance. You will now explore the effects of having

an inductive load in your circuit.

Step 12: Modify the 1k ohm resistor in the load to 50ohms. Add a 10mH inductor to your

circuit in series with your 500 ohm resistance (the resistor and inductor should still be in

parallel with the capacitor in your circuit).

Step 13: Click “Simulate” in the top toolbar and choose “Parameter sweep”. Use the same

configuration you had from your previous run and click “Simulate”. Take a screen shot of your

results for your lab report and comment on what changed in the resulting output and why.

Challenge Question 1: Voltage ripple relies heavily on the switching frequency and corner

frequency of your LC lowpass filter. Calculate the corner frequency of this buck converter,

determine a switching frequency that will increase V ripple, and modify the PWM generator

with your new switching frequency value. This can be done by double clicking on the PWM

function and changing the reference frequency. Rerun a transient analysis and comment on

whether the change gives the expected results.

Challenge Question 2: There is a significant amount of power lost in the buck converter diode.

Explain why this is the case and suggest ways to improve the efficiency of your buck converter.

For example, you might suggest additional circuitry.

2.4f Build and Explore the Buck Converter on a myProto Breadboard

The circuit built in Multisim utilized power transistors in its design, these will be replaced with

Insulated Gate Bipolar Transistors in the breadboard design and the gate driver from Lab 0 will be

used to control the transistors. Comment on how this will influence the results of the breadboard

circuit in your lab report. Also talk about the importance of the diodes placed across each transistor.


Step 14: Build the Buck converter on your myProto protoboard using Insulated Gate Bipolar

Transistors (IGBTs). The design should follow what you designed in Multisim, and you should build

the gate driver from Lab 0 to properly control the IGBTs. Use values for the resistor, capacitor and

inductor similar to that used in the initial Multisim design. The PWM generator will be replaced with

the Analog output 0 line from the myDAQ. You may use the block diagram in Figure 5 to assist in

building the buck converter circuit.

Figure 5 Buck Converter Block Diagram

Step 15: Connect the myProto to your myDAQ and plug the myDAQ into your computer.

Step 16: Open the myDAQBuckBoost.vi and modify the Frequency (Hz) and Duty Cycle (%)

controls to 1000Hz and 10% respectively. Run the code and observe the instantaneous signals. Use

the myDAQBuckBoost.vi to fill in the Table 1 (included at the end of the lab). Include this table

along with a screenshot of the instantaneous signals from the VI front panel in your lab report.

Step 17: Choose three other capacitor and three other inductor values to test in your circuit. The

capacitor and inductor values should fall in the same range as those used in the parameter sweep

with one value falling at the low end, the second at the high end, and the last in the middle of the

range. Swap pairs of these components into your circuit and fill out a copy of Table 1 for each using

the myDAQBuckBoost.vi. Include all of these tables as well as screenshots from the VI front panel

of the instantaneous signals that correspond to each table in your lab report. (You do not need to

have more than three tables for your lab report).

Step 18: Explore the block diagram of the myDAQBuckBoost.vi and gain an understanding of how

signals are generated and what form of analysis is being used.


2.5 Create a Lab Report Complete a 3-5 page report that includes all pictures, tables, observations and answers to questions


your lab report. Include an introduction, a results section, and a conclusion that also explains one

practical application of a Buck Converter.



Challenge: Explore the PCB Design

Attached are schematics for the buck converter circuit. These can either be used to add to the lab




Switching

Frequency(Hz)

Duty Cycle(%) Vout DC(V) Vout RMS(V) Iout DC(A) Iout RMS (A) DC Output

Power (W)

Inductance(mH)

Capacitance(uF)

Table 1 Experimental Observations


L A B 3

Boost Converter Lab One Hour


3.1 Goal To understand the basics of a boost converter circuit, common transistors used in power electronics,

and National Instruments hardware.


Simulate a boost converter circuit in Multisim software.

Build and interact with a step up, DC to DC converter circuit, commonly known as a boost

converter. You will design the circuit to output a switch DC voltage that varies according to

switch frequency and duty cycle.





the lab.


Hart, Daniel W. Power Electronics. New York, NY: McGraw-Hill 2011. Print Sections: 1.4, 6.4 Mohan, Ned, Undeland, Tore M, Robbins, William P. Power Electronics: Converters Applications and Design. Danvers, MA: John Wiley and Sons 2003 Sections: 2.1-2.8, 7.4 myDAQ References: Get Started Using NI myDAQ with LabVIEW for Education







begin the lab.

a. Explain the principles of voltage increment in a boost converter.

b. How is the PWM signal generated and applied to a transistor? Explain the switching

procedures in a turn-on and turn-off process.

c. What are advantages and disadvantages of a boost converter?

3.4 Lab Procedure





Gate Driver has been purposely removed in order to emphasize the boost converter

configuration.

Design the following circuit in Multisim. Double click the PWM_Generator and set a Reference

signal frequency of 5 kHz.

Figure 6 Boost (Step Up) Converter Circuit




PWM_Generator – PWM function used to generate the boost converter control signal, found in



for location.




Power_MOSFET– Power transistor used to switch the DC supply in order to provide an

alternating signal for the boost converter. Found in Group: Transistors; Family: Power_Mos_N.













parameters:







“Remove”.



include in your lab report. In this setup we have achieved a duty cycle ( ) of 40%, use the


following equation to calculate the expected output voltage then use the cursors in your

transient analysis to measure what the average voltage of you output is. In your lab report

document the calculated and simulated output voltages. Calculate the percent error of your

data and comment on why you believe there to be an error.

Equation 1 Boost converter output voltage equation







signal’s duty cycle, the boost converter capacitance, inductance, and load inductance.







Parameter: dc

Start: 100 mV

Stop: 950 mV

Number of points: 6




Click “Simulate” to run the parameter sweep. This will create six instances of your boost







Step 7: Pick five different frequencies evenly spaced out in the range from 50Hz to 20 kHz.




frequency.




decreased to change the high frequency content allowed through your boost converter. Next,

you will explore how you can change the response of the filter and its effects on the boost

converter DC output.





Name: L1


Start: 1 mH

Stop: 100 mH

Number of points: 6



report and comment on the impact of the inductance in your boost converter. Include in your


current.





Name: C1


Start: 1 uF

Stop: 200 uF





report and comment on the impact of the capacitance in your boost converter. Include in your

comment a theoretical explanation of the capacitor and its response to change in voltage and

current.











Challenge Question 1: Explain the critical values of a boost converter. Describe how the

frequency, inductance and capacitance values determine the operation modes.

Challenge Question 2: Explain the discontinuous current mode and continuous current mode

of operation. What differences are observed in each mode?

Challenge Question 3: Describe a 1-quadrant, 2-quadrant and 4-quadrant converter.

3.4f Build and Explore the Boost Converter on a myProto Breadboard





Step 14: Build the Boost converter on your myProto protoboard using Insulated Gate Bipolar






building the boost converter circuit.

Figure 9 Boost Converter Block Diagram


















practical application of a Boost Converter.





Attached are schematics for the boost converter circuit. These can either be used to add to the lab



Switching

Frequency(Hz)


Power (W)

Inductance(mH)

Capacitance(uF)



L A B 4

Buck Boost Converter Lab One Hour


4.1 Goal To understand the basics of a buck boost converter circuit, common transistors used in power

electronics, and National Instruments hardware


Simulate a buck boost converter circuit in Multisim software.

Build and interact with a step up step down, DC to DC converter circuit, commonly known as a

buck boost converter. You will design the circuit to output a switch DC voltage that varies

according to switch frequency and duty cycle.





the lab.


Hart, Daniel W. Power Electronics. New York, NY: McGraw-Hill 2011. Print Sections: 1.4, 8.1-8.4 Mohan, Ned, Undeland, Tore M, Robbins, William P. Power Electronics: Converters Applications and Design. Danvers, MA: John Wiley and Sons 2003 Sections: 2.1-2.8, 7.2-7.4 myDAQ References: Get Started Using NI myDAQ with LabVIEW for Education







begin the lab.

a) Obtain the relation of the output voltage, input voltage and duty cycle in a buck-boost

converter. Explain how the circuit operation reduces and boosts the voltage.

b) Explain the advantages and disadvantages of a buck-boost converter.

4.4 Lab Procedure





Gate Driver has been purposely removed in order to emphasize the buck converter

configuration.

Design the following circuit in Multisim. Double click the PWM_Generator and set a Reference

signal frequency of 5kHz.

Figure 10 Buck Boost Converter Circuit




PWM_Generator – PWM function used to generate the buck converter control signal, found in



for location.




Power_MOSFET– Power transistor used to switch the DC supply in order to provide an

alternating signal for the buck converter. Found in Group: Transistors; Family: Power_Mos_N.













parameters:







“Remove”.



include in your lab report. In this setup we have achieved a duty cycle ( ) of 40%, use the


following equation to calculate the expected output voltage then use the cursors in your

transient analysis to measure what the average voltage of you output is. In your lab report

document the calculated and simulated output voltages. Calculate the percent error of your

data and comment on why you believe there to be an error.

Equation 2 Buck Boost converter output voltage equation







signal’s duty cycle, the buck converter capacitance, inductance, and load inductance.







Parameter: dc

Start: 100 mV

Stop: 950 mV

Number of points: 6




Click “Simulate” to run the parameter sweep. This will create six instances of your buck boost







Step 7: Pick five different frequencies evenly spaced out in the range from 50Hz to 20kHz.




frequency.

Full Bridge Inverter 50



decreased to change the high frequency content allowed through your buck boost converter.

Next, you will explore how you can change the response of the filter and its effects on the buck

boost converter DC output.





Name: L1


Start: 1 mH

Stop: 100 mH

Number of points: 6



report and comment on the impact of the inductance in your buck converter. Include in your


current.





Name: C1


Start: 1 uF

Stop: 200 uF





report and comment on the impact of the capacitance in your buck boost converter. Include in

your comment a theoretical explanation of the capacitor and its response to change in voltage

and current.











Challenge Question 1: Draw a non-inverting buck-boost circuit, and illustrate the

circuit operation.

Challenge Question 2: Explain the technical issues of a transistor using a voltage

controlled voltage source.

4.4f Build and Explore the Buck Boost Converter on a myProto

Breadboard





Step 14: Build the Buck converter on your myProto protoboard using Insulated Gate Bipolar






building the buck boost converter circuit.

Figure 13 Buck Converter Block Diagram


















practical application of a Buck Boost Converter.








Switching

Frequency(Hz)


Power (W)

Inductance(mH)

Capacitance(uF)



L A B 5

Full Bridge Inverter Lab One Hour


5.1 Goal To understand the basics of a full bridge inverter, common transistors used in power electronics, and

National Instruments hardware.


Simulate a full bridge inverter circuit in Multisim software.

Build and interact with an inverter circuit on a myProto breadboard. You will design the circuit

to output a sinusoidal voltage that you will then observe under different load conditions.




Review the following resources to familiarize yourself with the topics listed before you begin the

lab.

Textbook References: Hart, Daniel W. Power Electronics. New York, NY: McGraw-Hill 2011. Print Sections: 1.4, 8.1-8.4 Mohan, Ned, Undeland, Tore M, Robbins, William P. Power Electronics: Converters Applications and Design. Danvers, MA: John Wiley and Sons 2003 Sections: 2.1-2.8, 8.1-8.3 myDAQ References: Get Started Using NI myDAQ with LabVIEW for Education







Complete the following quiz to check your understanding of the relevant topics before you begin

the lab.

a. What are the desired characteristics of ideal controllable switches?

a) Block arbitrarily large forward and reverse voltages with zero current flow when

off.

b) Conduct arbitrarily large currents with zero voltage drop when on.

c) Instantaneously change between on and off state and vice versa.

d) Negligible power required to control the switch

b. List 3 controllable switches, draw and label their circuit symbol, and draw their i-v

characteristics curve.

a) Bipolar Junction Transistor

b) Metal Oxide Semiconductor Field Effect Transistor

c) Thyristor

d) Isolated Gate Bipolar Transistor

c. Draw a full bridge inverter circuit and label the path of current in the forward and reverse

states. Discuss where the load should be as well as how the direction of current is changed

during operation.

d. Draw the timing diagram that can be used to achieve the PWM signal needed to control

the full bridge inverter. Label the reference control signal and switching triangle signal

then, using the switching scheme, draw the resulting PWM signal.

e. List all the steps and I/O lines needed to acquire an analog signal and output that same

signal using myDAQ and LabVIEW express VIs.


5.4 Lab Procedures

5.4a Design a Multisim Circuit

Designing a circuit in Multisim allows you to gain an understanding of the circuit you will

prototype on a breadboard later. MOSFET power transistors are used in simulation instead of

the IGBTs used in prototyping, and the gate driver circuit from Lab 0 has been purposely

removed in order to place emphasis on the full bridge configuration.

Build the following circuit in Multisim.

Figure 14 Full Bridge Inverter Circuit



PWM_GeneratorA/B – PWM function used to generate the inverter control signals found in


Control_Signal/Control_Signal_Delayed – Reference sinusoidal signal used to generate PWM

control signals. The two are used in order to create control signals for the positive and negative

peaks of the output sinusoid. They are found in Group: Sources; Family:

Signal_Voltage_Sources.


VCVS_A/B – Voltage Controlled Voltage Source used to provide a constant voltage regardless

of the current requirements of the load, in this case the MOSFET. Found in Group: Sources;

Family: Controlled_Voltage_Sources.

Power_MOSFET_1-4 – Power transistor used to switch the DC supply in order to create an AC

output signal. Found in Group: Transistors; Family: Power_Mos_N.

You can use wires or on-page connectors to wire up the circuit.

For more information about working with Multisim, visit:

https://www.youtube.com/user/ntspress/search?query=multisim.




Step 2: Label the wire between your capacitor and inductor by right clicking on it and choosing

“Properties”. Then under the Net name tab, update the “Preferred net name” field with a

descriptive name of your choice and click “Ok”.


Step 3: Click on “Simulate” on the top toolbar and navigate to Analyses>>Transient Analysis.

In the pop up configuration window choose the “Analysis parameters” tab and set the






Navigate to the “Output” tab and click “Add expression”. In this configuration window, seen in

Figure 16, you can add variables that are signals from the diagram then you can use a function

step to carry out an operation. Double click on the signals to populate the Expression field. You

are trying to differentially read the voltage across the capacitor, this means you want to take

the voltage at the node between the capacitor and inductor and the node at the other end of

the capacitor and subtract those two values. Once completed, press “Ok”; the expression

should already be included in the “Selected Variables for analysis” window.


Click “Simulate” to run the transient analysis. Take a screen shot of your results to include in your lab

report.


5.4c Perform a Parameter Sweep

A parameter sweep gives you an idea of how your circuit will respond with different values for

components such as resistors and capacitors. This sweep can be fine-tuned to allow you to find

the optimum point of operation for you circuit, so when you prototype your circuit with real

components you can have an idea of the range of component values you can use to achieve a

satisfactory output.

Step 4: Click on “Simulate” on the top toolbar and navigate to Analyses>> Parameter Sweep.

In the Pop up window, navigate to the “Analysis parameters” tab and set the following

parameters:


Start: 1uF

Stop: 100uf

Number of points: 5


Verify on the “Output” tab that the “Selected variables for analysis” field shows the expression

you created during your transient analysis step. Click “Simulate to run the parameter sweep.

This will create five instances of your inverter output, which corresponds to the five different

capacitance values tested during the sweep. Take a screen shot of your results to include in

your lab report.

Challenge Question 1: The two sinusoidal reference signals, Control_Signal and

Control_Signal_Delayed, are out of phase. Explain why this is important then experiment with

different phase angles and see how the output changes. Include your explanation as well as

any observations you make when changing the phase angle between the two signals.

Challenge Question 2: The voltage controlled voltage sources in the inverter circuit are used

to supply a voltage regardless of the loads current requirement in the ideal case. Describe

another circuit that can be built as a voltage controlled voltage source. Include your

explanation in your lab report.

Rectifier Lab 62

5.4d Build the Full Bridge Inverter on a myProto Breadboard

The circuit built in Multisim utilized power transistors in its design. These will be replaced with

Insulated Gate Bipolar Transistors in the breadboard design, and the gate driver from Lab 0 will

be used to control the transistors. In your lab report, comment on how this will influence the

results of the breadboard circuit. Also talk about the importance of the diodes placed across

each transistor.

Step 5: Build the Full Bridge Inverter on your myProto using Insulated Gate Bipolar Transistors

(IGBTs). Follow the design you did in Multisim. The gate driver from Lab 0 should be built and

replicated four times in order to be used to properly control the IGBTs. Use values for the

resistor, capacitor, and inductor similar to that used in the initial Multisim design. The PWM

generators will be replaced with the Analog output 0 and 1 lines from the myDAQ. You may

use the block diagram in Figure 17 to assist in building the inverter circuit. Connect the

myProto to your myDAQ and plug the myDAQ into your computer.

Figure 17 Full Bridge Inverter block diagram

Step 6: Open and Run the Inverter Lab.vi and observe the output waveform. Comment on

whether this waveform matches the simulation waveform. Are there any factors that would

cause this signal to be different from the signal received in Multisim?

Step 7: Choose 3 other capacitance values to test in your circuit. The capacitor values should

fall in the same range as those used in the parameter sweep with one value falling at the low

end, the second at the high end, and the last in the middle of the range. Swap these capacitors

into your circuit, run the Inverter Lab.vi, and take screen shots of the results for your lab report.

Rectifier Lab 63

Step 8: Open and observe the PWM control signals.vi. The implementation purposely did not

follow the theoretical solution for the PWM signals. Devise a means of realizing the theoretical

solution in LabVIEW, implement it and run it without being connected to the inverter circuit.

Take a screen shot of your generated signals for your lab report.

5.5 Lab Report Complete a 3-5 page report that includes all pictures, tables, observations and answers to

questions presented in the lab. Label all pictures with descriptive captions that relate them

back to content in your lab report. Include an introduction, a results section, and a conclusion

that also explains one practical application of a Full Bridge Inverter.

5.6 Final Observations Record other thoughts and observations you made throughout the lab and connect them to

something you have observed or experienced in the real world.





Rectifier Lab 64

Rectifier Lab 65

L A B 6

Rectifier Lab One Hour

Rectifier Lab 66

6.1 Goal To understand the basics of an uncontrolled and controlled rectifier circuit, common transistors used in

power electronics, and National Instruments hardware


Simulate a half and full wave uncontrolled rectifier circuit in Multisim software.

Simulate a full wave controlled rectifier circuit in Multisim software.

Build and interact with a controlled rectifier circuit. You will reference the AC signal in the

control mechanism to determine when to switch transistors.





the lab.

Textbook References: Hart, Daniel W. Power Electronics. New York, NY: McGraw-Hill 2011. Print Sections: 1.4, Mohan, Ned, Undeland, Tore M, Robbins, William P. Power Electronics: Converters Applications and Design. Danvers, MA: John Wiley and Sons 2003 Sections: 2.1-2.8, 5.3-5.4, 6.2-6.3 myDAQ References: Get Started Using NI myDAQ with LabVIEW for Education





Rectifier Lab 67


Complete the following quiz to check your understanding of the relevant topics before you begin the

lab.

f. Explain the operation of a thyristor and its principle differences with a transistor and a

diode.

g. How does the line commutation stop the current in a thyristor?

h. What happens if a highly inductive load is connected to a phase-controlled rectifier?

6.4 Lab Procedure Part 1: Half and Full Wave

Uncontrolled Rectifiers





Gate Driver has been purposely removed in order to emphasize the boost converter

configuration.

Design the following half wave rectifier circuit in Multisim.

Figure 18 Boost (Step Up) Converter Circuit


V1 – AC Power source found in Group: Sources; Family: Power_Sources.

Rectifier Lab 68

The diode resistor and capacitor are fundamental components that can be found at the top

toolbar of Multisim. The two sections to look under are “Place Diode” and “Place Basic”.










parameters:







“Remove”.

Rectifier Lab 69

Figure 20 Selecting rectifier output


include in your lab report. Use the following equation to determine the ripple voltage of the

current circuit configuration. Compare and comment on how close the simulated data is to the

theoretical calculation. You can find the ripple voltage of your signal by using the cursors of

the parameter sweep display and setting one to measure the lowest point of the voltage signal

and one to measure the highest point then taking the difference. The cursors can be obtained

by selecting Cursor>>Show Cursor from the top toolbar of the simulation window. You can

then move the cursors on the graph to your desired points. Calculate the percent error of the

theoretical versus simulated data.

Equation 3 Half wave rectifier ripple voltage equation

Rectifier Lab 70

6.4c Perform a Parameter Sweep (Half Wave Rectifier)





achieve a satisfactory output.






Name: C1 (the name of the discrete capacitor you placed on your schematic)


Start: 1 uF

Stop: 10 uF

Number of points: 5




Click “Simulate” to run the parameter sweep. This will create five instances of your rectifier

output, which correspond to the five different capacitor values in your sweep.

Take a screen shot of your results to include in your lab report. Make a prediction as to what

the output will look like for the full wave rectifier state why you believe this will be the case.

Step 7: Design the following full wave rectifier circuit in Multisim.

Rectifier Lab 71

Figure 21 Full Bridge Rectifier

6.4d Perform a Parameter Sweep (Full Wave Rectifier)

The full wave rectifier has a load between its two diode branches. We will conduct the same parameter

sweep done in section 6.4 but now the output will be taken as the difference between the two points of

the load instead of just with reference to ground.

Step 8: Double click on the wires on either side of the capacitor and resistor as seen in Figure 22 and, in

properties, give them each a descriptive name.

Figure 22 Rectifier load labeling

Step 9: Navigate to the “Parameter Sweep” analysis and select the same parameters from the previous

parameter sweep this time still choosing the capacitor as the component you will be sweeping.

Step 10: Navigate to the “Output” tab and choose “Add Expression”. Double click on the name you

gave to the wire branch on the left of the load, double click on the subtraction function then double click

on the name you gave to the wire branch on the right of the load. Click “Ok” then click “Simulate”

Step 11: Click “Simulate” to run the analysis. Take a screen shot of the output for your lab report. Use

cursors on the signal with the largest swing, which corresponds to the 1uF capacitance test, and find the

difference between the lowest and highest point in the signal. Comment on how this compares to the

half wave rectifier ripple voltage. Comment on why this is the case making sure to provide equations to

support your answer in your lab report.

Rectifier Lab 73

Challenge Question 1: Draw the circuit for a three phase uncontrolled rectifier circuit and

provide and explanation on how it works and its benefit.

Challenge Question 2: Explain what would happen to the output signal if the frequency of the

input signal were to increase while everything else stayed the same

6.4e Build and Explore the Uncontrolled Rectifier on a myProto Breadboard

Step 12: Build the full bridge rectifier circuit following the design done in Multisim. You may follow the block

diagram in Figure 23 for a reference on connecting to your myDAQ.

Figure 23 Rectifier Block Diagram

Step 13: Connect the myProto to your myDAQ and plug the myDAQ into your computer. The NI ELVIS

Instrument launcher should appear on your desktop letting you know your device has been detected.

Step 14: Open the myDAQRectifier.vi, select your myDAQ device from the device drop down control and

run the VI. Navigate to the “Uncontrolled Rectifier” tab to observe the input and output waveform.

Comment on how this compares to the output signals from your simulation in your lab report.

Step 15: Vary the input signal frequency and note how this influences the output signal. Comment on this in

your lab report.

Rectifier Lab 74

6.5 Lab Procedure Part 2: Phase Controlled Full

Bridge Rectifier

6.5a Multisim SCR Simulation

Step 16: Design the following Silicon Controlled Rectifier (SCR) circuit in Multisim.

Figure 24 SCR circuit

Step 17: Double click on the pulsed voltage source V2 and set the following parameters:

o Initial Value: 0

o Pulsed Value: 5

o Delay Time: 5m

o Pulse Width: 5m

o Period: 20m

Step 18: Double click on the pulsed voltage source V3 and set the following parameters:

o Initial Value: -5

o Pulsed Value: 0

o Delay Time: 12m

o Pulse Width: 8m

o Period: 20m

Rectifier Lab 75

Setting these values for the two pulsed voltage sources creates two pulse trains, one for the positive half of the

AC input and one for the negative half. These pulse trains will trigger the SCRs at specific times in order to

control how much signal is transmitted to be filtered for the DC output.

6.5b SCR Transient analysis

Step 19: Label the wire branches on both ends of the resistor load with descriptive names. This will be used to

aid in creating an expression for these two branches.

Step 20: Click “Simulate” on the top toolbar and navigate to Analyses>>Transient Analysis. In the pop up

configuration window, choose the “Analysis parameters” tab and set the following parameters:




Step 21: Using the same technique from steps 9 and 10, create an expression that will take the voltage at the

load as the difference between the voltages at each end of the load.

Step 22: Click “Simulate” to run the analysis, comment on what happens when the output signal has a zero

crossing in your lab report. Also include how the output signal as seen here will influence the DC signal that will

be derived from this. Explain how changing where you trigger the SCR affects the DC output. Include a picture of

the output in your lab report.

Step 23: Vary the delay time and pulse width of both signals making sure that they always add to 10ms for V2

and 20ms for V3. Run the transient analysis again with the new delay and pulse width times and take a picture of

your new results to include in your lab report.


presented in the lab. Label all pictures with descriptive captions that relate them back to content in your lab

report. Include an introduction, a results section, and a conclusion that also explains one practical application

of a Boost Converter.

Rectifier Lab 76

6.7 Final Observations Record other thoughts and observations you made throughout the lab and connect them to something you

have observed or experienced in the real world.


Attached are schematics for the uncontrolled and controlled full wave rectifier circuit. These can either be

used to add to the lab experience with an additional PCB design section or help reduce prototyping time for

students if boards are created before the lab by lab assistants.

power electronics lab manual_with_cover

Documents

national instruments

important information

warranty period

product information

software media

warranty work

latest contact information

introductory lab series