dsp-based hands-on laboratory experiments for photovoltaic power systems

IEEE TRANSACTIONS ON EDUCATION, VOL. 58, NO. 1, FEBRUARY 2015 39

DSP-Based Hands-On Laboratory Experiments forPhotovoltaic Power Systems

Polycarp I. Muoka, Member, IEEE, Md. Enamul Haque, Senior Member, IEEE, Ameen Gargoom, Member, IEEE,and Michael Negnetvitsky, Senior Member, IEEE

Abstract—This paper presents a new photovoltaic (PV) powersystems laboratory module that was developed to experimentallyreinforce students' understanding of design principles, opera-tion, and control of photovoltaic power conversion systems. Thelaboratory module is project-based and is designed to support arenewable energy course. By using MATLAB real-time softwaretools in combination with digital signal processor (DSP) hardwaretools, the module enables students to: 1) design and build dc–dcand dc–ac power converters; 2) design and implement controlalgorithms for maximum power point tracking (MPPT) andvoltage and current regulation; and 3) design and fabricate aprinted circuit board for voltage and current sensing, isolation,and gate driving. In these hands-on experiments, by designing andbuilding their hardware and software integrated systems them-selves, students learn by doing and experience the engineeringtransformative process of building a product out of an idea. Thispaper is motivated by the dearth of literature on the applica-tion of project-based learning methodology to PV systems. Themodule description, the pedagogical and evaluation methodologiesadopted, and reflections on the implementations are discussed.

Index Terms—dc–dc power conversion, digital signal processors,energy conversion, photovoltaic power systems.

I. INTRODUCTION

T HERE is an exponential increase worldwide in the pen-etration level of photovoltaic (PV) generated energy into

the grid system. This increased penetration level offers uniquechallenges to systems operators. In addition to challenges of in-tegration, significant challenges remain in the areas of: 1) in-creasing the energy harvested from the sun; 2) lowering thecost of components needed for energy conversion to achieveparity with coal-fired electricity; and 3) improving reliability soas to reduce replacement cost during the life of the system [1].Solving these will require an extensive pool of well-trained andcompetent engineers to design, install, operate, and maintainsuch systems [2], [3].

Manuscript received October 14, 2013; revised February 27, 2014 and April16, 2014; accepted May 02, 2014. Date of publication May 29, 2014; date ofcurrent version January 30, 2015.The authors are with the Centre for Renewable Energy and Power Systems,

School of Engineering, University of Tasmania, Hobart, Tas. 7001, Australia(e-mail: [email protected]; [email protected]; [email protected]; [email protected]).Color versions of one or more of the figures in this paper are available online

at http://ieeexplore.ieee.org.Digital Object Identifier 10.1109/TE.2014.2323937

Fig. 1. Block diagram of PV power system as designed and built.

Currently, there is a dearth of such skilled engineers. Ad-dressing this requirement needs unique interventions and col-laborations among industry, government, and academia. Whilevarious initiatives by IEEE and the US Department of Energy(DOE) are inspiring and commendable, the onus lies with theuniversities [4]. There is a need for university-level ElectricalEngineering programs to review their curricula, especially thelaboratory aspects, so as to produce a generation of engineerscompetent both with their brains and their hands. This can ef-fectively be achieved by using an inspiring educational alterna-tive that is problem-based, project-based, and hands-on [5], [6].This paper describes a one-semester laboratory module

aimed at producing skilled, innovative, and career-ready en-gineers who are knowledgeable in PV energy systems. Inthis module, students design, build, and test a PV electricalenergy conversion system, shown in Fig. 1. Power electronicconverters are used to interface with, and efficiently use theenergy from, PV solar panels. Students design and build asingle-ended primary inductance converter (SEPIC) converterfor stepping up and regulating the variable dc output of the solarpanels, as well as a single phase dc–ac converter (inverter). Thedigital signal processor (DSP)-based control system ensures:1) operation at maximum power point (MPP); 2) voltage andcurrent regulation; and 3) system monitoring and protection.A number of papers [6]–[8] have discussed the applications

and advantages of the project-based laboratory (PBL) method-ology in undergraduate electrical engineering education. Whilepower electronics and motor drives have been the focus of suchpapers [9], [10], the present paper is unique in that, to the bestof the authors' knowledge, no papers in the literature apply PBLmethodology to the area of PV renewable energy systems.

0018-9359 © 2014 IEEE. Personal use is permitted, but republication/redistribution requires IEEE permission.See http://www.ieee.org/publications_standards/publications/rights/index.html for more information.

40 IEEE TRANSACTIONS ON EDUCATION, VOL. 58, NO. 1, FEBRUARY 2015

II. MOTIVATIONS, OBJECTIVES, AND DESIGN

A. Motivations

The development of the PV lab module to support the Re-newable Energy course KNE 343 at the University of Tasmania,Hobart, Australia, was motivated by the observed shortcomingsof some traditional—and even some modern—approaches toteaching laboratory classes to electrical engineering students.These approaches include the following.1) Demonstration by Instructor: In this approach the in-

structor demonstrates the experiment, while the students ob-serve and take notes. This approach is often used because ofhazards associated with high voltage or because of limited avail-ability of laboratory equipment. However justified this approachmay be, it fails to motivate or excite students, or to develop theirself-confidence [10].2) Prepared Lab Handout: In this traditional approach,

used in most universities to teach engineering, students workin groups, following the instructions of a lab handout to set upa circuit, take specified readings, and then analyze the results.However, this approach is also found to be ineffective in gener-ating students' enthusiasm and passion for learning [10], [11],mainly because they are never involved in the design andconstruction stages of setting up the initial experiment.3) Blue-Box Approach [12]: Students are provided with pre-

built circuits on which they take measurements, again withoutbeing involved in the design and construction processes. Thisapproach also fails to generate students' interest.4) Software-Based Approach [12]: This approach relies

on the use of computers and software packages for simulationand experimentation. Students use no physical componentsand instrumentation. They can do experiments with a modelof a MOSFET power switch, for example, without touching orseeing the switch physically.5) Web-Based Approach [12]: This relies on the Web for

teaching laboratory experiments. Despite being cheap and safeto operate, this approach deemphasizes the hands-on use ofphysical components and instruments.

B. Lab Module Learning Objectives

With the prime motivation of producing career-ready engi-neers, capable intellectually and practically, the teachers for-mulated a set of specific technical and nontechnical learningobjectives, intended to equip students with the skills to do thefollowing:• evaluate and analyze PV characterization and the interac-tions of PV subsystems;

• design and build capability of power converters used in PVenergy harvesting, conditioning, and interfacing;

• design, build, and analyze analog and digital control cir-cuits associated with PV power processing;

• design controllers for maximum power pointtracking (MPPT), voltage and current regulation,and system protection in PV systems;

• use test equipment and instruments proficiently in PV sys-tems applications;

• engage in teamwork, project management, and productdesign;

TABLE ILAB MODULE SCHEDULE

• communicate efficiently and write and present technicalreports and papers.

C. Module Details and Schedule

The semester-long laboratory module is intended for senior-level undergraduate electrical engineering students. They areexpected to have taken both a power electronics course andthe theoretical course on renewable energy systems. The courseinvolves using DSP controller hardware and software tools inconjunction with MATAB/Simulink software tools for the de-sign and control of power converters. The converters are imple-mented using insulated gate bipolar transistors (IGBTs).The module incorporates the following key tasks. Students

must: 1) design and build a 300-W dc–dc converter based oneither Boost converter or SEPIC converter topology to producean output voltage of 180 V dc; 2) design and build a 300-Winverter based on the H-bridge topology to produce a 240-V,50-Hz pure sine wave; 3) design and build a single-sidedprinted circuit board (PCB) for data acquisition, isolation, andgate drive; and 4) develop DSP-based control systems for theconstructed power circuits. The experimental schedule shownin Table I is provided as a guide to the students.

D. Key Design Decisions

In designing the lab module, major decisions were based onconsideration of the following key areas.• Contents and constraints: The learning objectives, dis-cussed earlier, were used as roadmaps to formulate thelaboratory module's contents. Other key questions werethe following:• What background did students have in power electronicsand control engineering?

MUOKA et al.: DSP-BASED HANDS-ON LABORATORY EXPERIMENTS FOR PHOTOVOLTAIC POWER SYSTEMS 41

• How measurable were the learning outcomes? What as-sessment strategies should be used?

• Which of the students' ancillary skills neededimprovement?

• Class size: What sized group should be used for effectiveactive learning? Three or at most four students per groupwere considered as optimal. Was there enough equipmentfor the number of groups dictated by this and by the classsize?

• Equipment cost and availability: Was the hardware costto-student ratio justifiable? How readily available were thekey components?

• Support structure: For effective management of the labmodule, what support staff in terms of teaching assistants,lab assistants, and IT support staff were available? Forreasons of cost and convenience, the team decided to useavailable postgraduates, departmental lab assistants, andIT personnel, rather than hire new personnel.

• Choice of controller technology: Should this be an analogsystem, a field-programmable gate array (FPGA) with itsassociated VHDL software, a DSP-based system, or anapplication-specific integrated circuit (ASIC)? The DSP-based platform was eventually chosen because it offers: 1)better optimization; 2) lower cost; 3) lower latency; and4) easier hardware/software integration work [13]. This isbecause of its reliance on the MATLAB/Simulink softwarethat is widely used.

III. PEDAGOGICAL APPROACHES

A. Pre-Lab Assignments

In a pre-laboratory exercise that precedes the constructionphase, students do analytical designs for the power and controlcircuitries, based on provided specifications, and then simulatetheir developed models in MATLAB/Simulink and SimPower-Systems software. Before proceeding to the construction phase,each three-student project group is expected to perform the sim-ulation studies using a provided working model of a solar panel.

B. Tutorials on Applicable Software and Hardware

The first 3 weeks of the semester are devoted to simulationstudies of the entire system and tutorials to familiarize the stu-dents with Altium and dSPACE ControlDesk software. The Al-tium software is needed for designing and building the PCBsfor data acquisition, and for the isolation and gating require-ments of the power switches. The tutorials on Altium centeron PCB design, manufacture, and board assembly. The Con-trolDesk software is used for interactions with the controller viathe graphical user interface (GUI); the tutorials on ControlDeskfamiliarize the students with how to: 1) implement their controlalgorithm on the DS1104 R&D system; 2) interface external de-vices and sensors to the DS1104 systems; and 3) build the re-quired GUI using the software. During this period, the studentsare also made aware of the assessment criteria to be used and thesafety rules to be followed in the implementation of the project.

Fig. 2. Sample schematic diagram of one channel of the sensing board showingvoltage sensing circuitry.

C. “Do-It-Yourself” Hands-On Fabrication

1) Experimental Setup: The major items in the experimentalsetup for each project group are: 1) a personal computer (PC)loaded with MATLAB, ControlDesk, and Altium software; 2) adigital oscilloscope; 3) bench top power supplies; 4) a DS 1104DSP controller hardware interface; 5) measuring and test instru-ments; 6) a soldering station; 7) a set of lab safety instructions;and 8) two BP 380 solar panels.The DS1104 R&D controller, made by dSPACE GmbH, is a

standard board that can be inserted into the peripheral compo-nent interconnect (PCI) slot of a host PC [14]. Designed for thedevelopment of high-speed multivariable digital controllers andfor real-time simulation, this DSP-based controller incorporatesthe following [14]:• a master DSP—603 PowerPC floating point pro-cessor—with a clock frequency of 250 MHz;

• a slave-DSP system based on the TMS320F240 DSPmicrocontroller;

• a 100-pin I/O connector for linking field signals, via anadapter cable;

• two different types of analog/digital converters (ADCs):1) one 16-bit ADC with four multiplexed input signals;2) four 12-bit parallel ADCs with one input signal each,used to acquire the various currents and voltages re-quired in the project;

• a digital/analog converter (DAC) with eight parallelDAC channels, used to output the pulse-width modula-tion (PWM) signals.

In addition, the interface connector CP1104 allows communi-cation between the controller board and external devices.2) PCB Construction: Each project group first implements

the schematic and layout design for the sensing, isolating, andgate driver PCB, using Altium software. The single-sided PCBsubsequently assembled has the following main components:1) Hall-effect voltage sensors (LV 25P) and current sensors(LA 55P); 2) instrument amplifiers: INA 118; 3) opto-couplers:HCPL-3120; and 4) IGBT gate driver ICs: IR2117. A sampleschematic diagram for one channel of the sensing board, illus-trated in Fig. 2, shows the voltage sensing and conditioning,and the layout design of a sample PCB produced by one groupis shown in Fig. 3.3) Construction of Power Converters: For the construction

of the SEPIC converter with 180 V dc output voltage, the IGBT


Fig. 3. Sample layout design of the PCB produced using Altium software.

with integrated freewheeling diode is mounted on a T0-220heatsink with thermal insulation in between the IGBT andheatsink. Once the marking and drilling of the mounting holesis done, the IGBT, the inductors, the diode, and the capacitorsare mounted on a 4-mm-thick perspex project box using bananasockets and 15-cm-long copper wire to facilitate componentretrievability and reusability.The SEPIC converter is popular with the students for its capa-

bility to step up and step down the input dc voltage to the desiredoutput voltage value based on the duty cycle. Other reasons forthe popularity of this converter topology include: 1) its outputbeing noninverted; 2) the input and output voltages being dcisolated by a coupling capacitor; 3) it having a true shutdownmode, in that when the power switch is turned off, the outputdrops to zero; and 3) it being operable within a wide voltagerange [15]. The governing equation for the SEPIC converter isgiven as [15]

(1)

where is the output voltage, is the input voltage fromthe solar panels, and is the duty cycle of the power switchgenerated by the DSP controller. From (1), the duty cycle isobtained as

(2)

From (2) it is seen that the magnitude of the output voltage of theconverter is controlled by the duty cycle generated by the con-troller. Thus, by controlling this parameter via the controller,the students can achieve their designed output voltage. To op-erate the power switch properly, one channel of the PCB fabri-cated earlier is used to provide the necessary isolation and drivecapability: 15 V dc from the low 5-V output of the controller.An example of the fabricated SEPIC converter with its perspexhousing is shown in Fig. 4.Similarly, the H-bridge-based inverter to produce 240 V ac

at 50 Hz is constructed using four IGBTs and housed in a sepa-rate perspex project box. The schematic circuit diagram of thissingle-phase H-bridge inverter is shown in Fig. 5. To turn onthe switches (Q1–Q4) properly, four channels of the PCB boardare used. This involves using four opto-coupler ICs and four

Fig. 4. Example of the fabricated 300-W SEPIC converter in perspex housing.

Fig. 5. Schematic diagram of the H-bridge-based inverter being constructed.

single-channel gate driver ICs for the high side switches (Q1and Q3) and the low side switches (Q2 and Q4).4) Control Algorithm Implementation: Using the pre-lab de-

veloped Simulink simulation model for the control system in-terfaced with real-time function blocks, the students are able toimplement control algorithms for: 1) MPPT; 2) voltage and cur-rent control for both converters; and 3) unipolar sinusoidal pulsewidth modulation (USPWM) for the inverter.To ensure the operation of the PV array at its highest effi-

ciency, whatever the weather conditions (constantly changinginsolation and temperature), an effective algorithm for MPPT isrequired. For this project, students have to design their MPPTcontrol using the incremental conductance technique (ICT),chosen for its unique advantages of high accuracy in rapidlychanging environmental conditions and moderate complexityof implementation [16], [17]. This technique tracks the MPPby comparing the incremental conductance to theinstantaneous conductance (I/V) of the PV array, as explainedin the flowchart of Fig. 6. Each project group must code thisflowchart into the control system.The automatic code generation feature of the Real Time

Workshop (RTW) subset of MATLAB enables easy conversionof these codes into the equivalent C codes. These C codesare subsequently compiled into executable codes, assembled,linked, and then downloaded to the DSP controller that isembedded in the host computer.With the code already downloaded into the embedded DSP

controller, the ControlDesk software on the host computer isthen used for the development of the graphical user interface


Fig. 6. Flowchart of the incremental conductance MPPT technique.

Fig. 7. Control signal flow block diagram of the DSP-controlled PV system.

(GUI). Part of the software development process for this lab re-quires the students to learn how to use the ControlDesk soft-ware to build the GUI for their control circuits designs. TheGUI enables real-time interaction with the embedded DSP con-troller and allows the students to change system parameters andto display and monitor waveforms on the host computer. Viathe GUI of the ControlDesk, the parameters of the various pro-portional-integral (PI) blocks are tuned in real time to achievethe desired output values. A switching frequency of 25 kHz ischosen for both converters, and a deadtime of 500 ns chosen forthe inverter.In this project, the students have to interface the feedback

control circuits via the ADC of the board. The outputs (PWMpulses) from the board are taken via the DAC and then fed viathe opto-coupler and the gate driver to the gate of the IGBTswitch. While the opto-coupler provides optical isolation be-tween the controller and the higher voltage, the gate driver con-ditions the 5-V pulse train of the controller to a 15-V pulse trainsuitable for driving the IGBT switches. Fig. 7 shows the blockdiagram of the signal flow for the system's control loop.5) Installation of Solar Panels: The two-panel solar array

is based on BP 380 solar panels, whose electrical parametersare given in Table II. The students have to find the optimal lo-cation for the array, near the laboratory to achieve optimumenergy harvesting from sunlight. Factors to consider are [18]:

TABLE IIELECTRICAL PARAMETERS OF BP 380 SOLAR MODULE@STC

1) proper orientation of the panels; 2) tilt angle from the hori-zontal; 3) shading issues from trees and buildings; 4) length ofthe dc cable from the array to the converter; and 5) the mete-orological data of the site. Students are provided with a KimoInstruments' SL 200 solarimeter with data logging functionalityfor irradiation/irradiance measurement and a clinometer for an-gular measurement.6) System Integration: The installation of the array of two

panels is followed by the integration of the filter network andthe 120/240-V step-up transformer provided, to realize the com-plete PV system as depicted in Fig. 1.

D. Experiments, Demonstrations, and Presentations

1) Experiments: Once the project group has verified that thevarious subsystems and the integrated system are working as ex-pected, they perform a range of testing andmeasurements, whensunlight is available, to investigate its behavior. In addition tothe investigations detailed in the grading rubric provided, viatheir ControlDesk-designed GUI the students are required to dothe following:• monitor and graph the analog inputs (currents and volt-ages) from the PV array and those of the converters usedin the feedback loops;

• investigate the effects of changes in reference setpoints andobserve the attendant changes in output as the input voltagechanges;

• tune the parameters of the PI controllers to understand howthese parameters influence the control response;

• observe and note how changes in input and load affect thesystem's performance.

Fig. 8 shows the effect on system performance of changingsolar radiation, looking at two different irradiance conditionsof 600 W/m at 20 C and 800 W/m at 20 C as recordedby one project group. The regulated voltage value of 180 V inboth Fig. 8(a) and (c) shows that the controller effectively regu-lates the output voltage of the SEPIC converter, despite differentoutput voltages of 30 and 40 V, respectively, coming from thePV array for these conditions. Also, the changing values of thetracked power with changes in solar intensity, Fig. 8(b) and (d),show the MPPT algorithm to be effective.2) Demonstrations and Presentations: During the last lab

session of the semester, each project group has to demonstrate


Fig. 8. Example of effects of changing solar radiation on system performance as displayed in ControlDesk. (a) dc link voltage (upper line) at 180 V and arrayvoltage (lower line) at 30 V for an irradiance of 600 W/m at 20 C for the BP 380 solar module-based array. (b) Extracted maximum power from the array at600 W/m at 20 C. (c) dc link voltage (upper line) at 180 V and array voltage (lower line) at 40 V for an irradiance of 800W/m at 20 C. (d) Extracted maximumpower from the array at 800 W/m at 2 0 C.

to the lecturer the operation of the system they built, showing thevarious waveforms generated. During these demonstrations, thelecturer poses questions to assess the contributions of individualmembers to the success of the project.The demonstration phase is followed by the presentation and

report submission phases, which play a large role in improvingstudents' nontechnical skills. In particular, the communicationskills of writing and oral presentation are the key targets of thiseffort.

IV. ASSESSMENT AND ANALYSIS

To assess the students' learning outcomes against a valid andreliable standard that is academically sound, transparent, andfair to all students, an assessment rubric based on the criteria ref-erence assessment (CRA) [19] was prepared, shown in Table III.The details of this assessment methodology, the surveys carriedout, and analyses of performance are discussed in this section.

A. Assessment Methodology

The learning outcomes were measured based on each group's:• formal report detailing their design approaches, diagrams,observations, and conclusions;

• PowerPoint-based presentation in which each membertakes turns to explain to peers and lecturers the operationof the entire PV system;

• demonstration of prototypes to supervisors and peers.

B. Student Survey

Post-activity surveys were administered in the penultimateweeks of the semesters for 2011 and 2012. The surveys used athree-part anonymous questionnaire. The first part of the ques-tionnaire was designed to find out if there had been an increasein students':• knowledge of PV systems;

TABLE IIIGRADING RUBRIC AND LEARNING OUTCOMES

• knowledge of power converters and control systems usedin PV systems;

• interest in PV systems;


TABLE IVSTUDENTS RATINGS OF THEIR ACQUIRED SKILLS

Fig. 9. Overall student rating of the lab module (a) year 2012 and (b) year 2011.

• confidence in designing an engineering product;• whether they had gained any transferrable skills in projectmanagement and teamwork.

The second part of the questionnaire asked students to rate thecourse on a scale of 0–10, where 0–4 was Unsatisfactory, 5–6was Neutral, 7–8 was Good, and 9–10 was Excellent.The third part of the questionnaire asked students their per-

spectives on the learning outcomes and their suggestions to im-prove the lab module in the future.

C. Analysis of Survey Results

All the 15 students who took part in the laboratory course in2012 participated in the survey. The results of the first part ofthe questionnaire, shown in Table IV, indicate that in general themodule achieved a favorable outcome. For the second part of thequestionnaire, requesting an overall rating of the module, eightof the 15 respondents (53.33%) rated it as being “excellent”; five(33.33%) rated it as being “good”; two of them (13.33%) wereneutral; and none of the respondents rated it as being “unsatis-factory.” Fig. 9(a) and (b) shows the distribution of this overallrating for 2012 and for the 12 respondents in 2011; the evalua-tions are seen to be very positive.Table V shows the questions posed and some students' re-

sponses in the third part of the questionnaire, which indicate

TABLE VSTUDENTS' COMMENTS

TABLE VISTUDENTS' SCORES IN % FOR THE GOALS IN 2012

that the lab module has to a great extent achieved some of theintended educational objectives.

D. Analysis of Performance Versus Goals

The main competencies the students have to acquire, basedon the learning objectives (Section II-B), are for the purposesof the analysis here grouped into six goals:• Goal 1: practical knowledge of PV systems componentsand characteristics;

• Goal 2: practical knowledge of PV-related converters;• Goal 3: skills in PV-related electronics andinstrumentation;

• Goal 4: skills in developing control algorithms for MPPT,voltage and current regulation, and system protection;

• Goal 5: teamwork and project management;• Goal 6: proficiency in communication.

Using the assessment rubric in Table III as a benchmark and inconjunction with the key assessment areas (report, PowerPointpresentation, and demonstration), the final marks for each goalfor 2012 are shown in Table VI. The marking is based on theAustralian educational grading system, which is explained asfollows: High Distinction (HD): 85%–100%; Distinction :75%–84%; Credit : 65%–74%; Pass : 50%–64%; andFail (FF): 0%–49%. Table VI gives the scores of the 2012 stu-dents in percentage. For instance, for the assessment of the stu-dents' performances in the Goal 1 competency group, one (7%)of the students scored aCredit grade, another (7%) scored aPassgrade, six (40%) scoredDistinction, while seven students (46%)scored High Distinction. Similar explanations are applicable tothe other competency groups shown in the table.Analyses of the goals show that the lowest marks (Pass

grade) were obtained by many of the students in the Goal 3competency, which deals with PV-related electronics and


Fig. 10. Overall average scores in the competency groups for 2011–2013.

TABLE VIISUMMARY OF REFLECTIONS ON METHODOLOGY

instrumentation—the fabrication of PCB for data acquisition.A similar observation was made for the 2011 lab session. Thisrelatively low performance had to do with the learning curveassociated with the Altium software used for the PCB design.Also, more students scored HD in the Goal 2 competencygroup compared to any other group because each project groupsuccessfully built functional power converters.Fig. 10 compares overall average performances for all goals

for 2011 (first year of course introduction), 2012, and 2013. Out-comes improved in 2012 and 2013, especially forGoal 6, whichdeals with communication skills. This is related to measurestaken by the teachers to ensure that students from non-English-

speaking backgrounds (mostly the international students) do not“cluster” in nationality-based groups as used to be the case. This“clustering” resulted not only in a relatively poor quality of re-port writing, but also in the oral presentation. Avoiding clus-tering by nationality improved outcomes by helping studentsto improve their language skills through interaction with nativeEnglish speakers.

E. Reflections

After 3 years of offering the module, a critical reflectionby the lecturers is summarized in Table VII. To keep abreastof technological changes and to minimize student plagiarism,the lab module contents, hardware, and software will be re-viewed every 3 years. The costs of IGBTs and other powerconverter components have recently come down, resulting ina low hardware-cost-to-student-number ratio for the project,given that four students can be assigned to a group. The 300-Wprototype boards are thus considered justifiable. In addition,the components are retrievable and reusable (Table VII), andthe designed converters can handle the power needs of the PVarray (two BP 380 panels) available in the lab irrespective ofthe array topology—parallel or series connection.

V. CONCLUSION

This paper has discussed a module that uses a vertically in-tegrated approach to hands-on laboratory experimentation forteaching PV systems. By designing and building the power con-verters and the data acquisition systems and developing the DSPcontrol systems in software, students experience the system-level context of their work and must consider the real-worldconstraints involved in developing a PV power system.Student feedback and assessment data indicate that the

learning objectives were achieved. It is hoped that the informa-tion presented here will assist electrical engineering educatorsdelivering courses in this area.

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Polycarp I. Muoka (S'10–M'13) received the B.E. degree in electrical engi-neering from the Ahmadu Bello University, Zaria, Nigeria, in 1988, and theMaster's degree in computer systems engineering from the University of SouthAustralia, Adelaide, Australia, in 2007, and is currently pursuing the Ph.D. de-gree in electrical engineering at the University of Tasmania, Hobart, Australia.He has many years of industrial working experience. His main research in-

terests include renewable energy systems, control systems, power electronics,and energy storage.

Md. Enamul Haque (M'97–SM'10) graduated in electrical and electronicengineering from Rajshahi University of Engineering Technology [formerlyBangladesh Institute of Technology (BIT)], Rajshahi, Bangladesh, in 1995,

and received the M.Eng. degree in electrical engineering from the Universityof Technology, Skudai, Malaysia, in 1998, and the Ph.D. degree in electricalengineering from the University of New South Wales, Sydney, Australia, in2002.He was an Assistant Professor with King Saud University, Saudi Arabia and

United Arab Emirates University for 4 years. He is currently working as a Se-nior Lecturer in renewable energy and power systems with the School of En-gineering, University of Tasmania, Hobart, Australia. His research interests in-clude smart energy systems, control and grid integration of renewable energysources and energy storage systems, microgrid systems with hybrid wind/solar/fuel cell systems, power electronics applications in smart-grids, and micro-gridand power system applications.

Ameen Gargoom (M'08) received the B.Sc. and M.Sc. degrees in electricaland electronic engineering from the University of Garyounis, Benghazi, Libya,in 1994 and 2001, respectively, and the Ph.D. degree in electrical power engi-neering from the University of Adelaide, Adelaide, Australia, in 2007.He worked as a Consultant Electrical Engineer designing commercial and

residential distribution systems for 6 years before starting his Ph.D. program. In2008, he joined the University of Tasmania, Hobart, Australia, where he workedas a Research Fellow for 2.5 years before accepting a Lecturer position with theSchool of Engineering in 2011. His present research interests include powerelectronics control, power quality monitoring techniques, application of signalsprocessing techniques to power systems, and renewable energy systems.

Michael Negnevitsky (M'95–SM'07) received the B.S.E.E. (Hons.) and Ph.D.degrees from the Byelorussian University of Technology, Minsk, Belarus, in1978 and 1983, respectively.Currently, he is Chair Professor in Power Engineering and Computational

Intelligence and Director of the Centre for Renewable Energy and Power Sys-tems with the University of Tasmania, Hobart, Australia. From 1984 to 1991,he was a Senior Research Fellow and Senior Lecturer with the Department ofElectrical Engineering, Byelorussian University of Technology. After arrivingin Australia, he was with Monash University, Melbourne, Australia. His inter-ests are in power system analysis, power quality, and intelligent systems appli-cations in power systems.Dr. Negnevitsky is a Chartered Professional Engineer and a Fellow of the

Institution of Engineers Australia.

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