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1 Practice oriented controls in company based training September 2018 Work-Based Learning in the Field of Cutting Mechanics
1
Practice oriented
controls in
company based
training
September 2018
Work-Based Learning in the Field of Cutting Mechanics
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To the extent possible under law, the person who associated CC0 with this
work has waived all copyright and related or neighboring rights to this work.
"The European Commission support for the production of this publication does not constitute an endorsement of the contents which reflects the views only of the authors, and the Commission cannot be held responsible for any use which may be made of the information contained therein."
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“Work-Based Learning in the Field of Cutting Mechanics:
Introducing VET Multipliers to Alternate Work-Based Learning in Romania and Slovakia”
2015-1-DE02-KA202-002514
Action Type: Strategic Partnerships for vocational education and training
Start Date: 01.09.2015 End Date: 31.08.2018 Project partners: Bildungswerk der Bayerischen Wirtschaft gGmbH - Coordinator Lisa Dräxlmaier GmbH DTR Draexlmaier Sisteme Tehnice Romania SRL Schaeffler Romania SRL SC Stabilus Romania SRL Scoala Profesionala Germana Kronstadt INA Kysuce spol. s r.o. Stredna odborna skola strojnicka
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Content
Core process model ........................................................................................ 5
Assessments ................................................................................................. 10
Bloom’s revised taxomony (English) .............................................................. 17
Taxonomiestufen nach Bloom (German) ....................................................... 18
Taxonomia revizuita a lui Bloom (Romanian) ................................................ 19
Taxonómia kognitívnych vzdelávacích cieľov podľa Blooma (Slovak) ........... 20
Example assesment method: worksheets ..................................................... 21
5
Core process model
In order for vocational education and training to have the desired results it has
to always take into account the development of business processes since it is
required to train the future workers which will have to be agile in these pro-
cesses.
Not only do the trainees need to understand how a business process works,
they also have to be able to adapt it to the needs of the market or other con-
straints.
At the same time, just like any production process in the world of labour,
training in a VET system also has different process component which need to
be taken into consideration when developing practice oriented assesments.
This is the reason why the assessment of the learning progress during com-
pany-based-training throughout the whole training period has to be done prac-
tice oriented.
The whole company environment and its processes have an influence on
company-based vocation education and training. At the same time the
different process of VET depend on each toher.
These dependencies are depicted in the following images.
6
The influence of company environment on the core processes of VET
7
The interdependecies of the VET core processes
8
Examples of VET core process elements
Marketing public/private
events print media
school fairs and visits
online media ...
Recruiting applications job postings interview,
assesment contract ...
Training places organisation
within company
callibration theory - practice
planing within VET center
health and safety
instruction ...
Start of apprenticeship
forming classes
internal organization regulation
signing contract
schedule ...
Vocational school
parent teacher meeting
registration teacher traner
meeting
health and safety
instruction ...
Lectures preparation selecting subjects
setting objectives
selecting media
...
Examination preparation setting
objectives implementation reexamination ...
9
Examples of VET core process elements – continuation
Evaluation feedback from teachers
feedback from students
education records
feedback from trainer
...
End of apprenticeship
recommendation job offer returning work
items ceremony ...
Trainer qualification
leadership training
conflict management
quality management
training of instructors
...
Leadership parent teacher meetings
absenteesm communication conflict
management ...
Maintenance facilities
maintenance waste
management facility
audit/inspection housekeeping ...
Procurement masterials tools equipment hardware/
software ...
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Assessments
What are assessments used for?
The most obvious use for assessment is to determine whether someone is
competent and has the specific skills and knowledge to do the job; which
would lead to the attainment of a qualification. However, because the compe-
tency standards described in training packages are industry-agreed bench-
marks, assessment can be used for other purposes on the job. For example,
classifications in industrial awards are sometimes linked to competency stand-
ards. Assessments may also be used to determine whether or not a person
can get a licence to work in a specific job role.
Who can conduct assessments?
Only qualified trainers or teachers with educational certificates can conduct
assessments leading to a national qualification or statement of attainment.
The assessors must have the relevant vocational competencies at least to the
level being assessed, and continue developing their vocational training and
assessment competencies.
If a person does not have the assessment competencies as outlined and the
relevant vocational competencies at least to the level being assessed, one
person with all the necessary assessment competencies or the relevant voca-
tional competencies at least to the level being assessed may work together to
conduct the assessments.
11
How are assessments conducted?
Assessment quite different from the formal examinations and tests most peo-
ple remember from their school days.
Evidences gathered to demonstrate competence in the skills and knowledge
required by the units of competency contained in training packages or accred-
ited courses.
Common types of assessment methods used by assessors to gather evidence
include:
Direct:
• direct observation
• oral questioning
• demonstration of specific skills.
Indirect:
• assessment of qualities of a final product
• review of previous work undertaken
• written tests of underpinning knowledge.
Third party:
• Testimonials from Employers
• Reports from Supervisors
• Work diary or log book
• Work reports or documents.
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The evidence used in assessment depends on the requirements of the particu-
lar units of competency or learning outcomes of a curriculum from the training
package or accredited course, and the preferences or needs of the person be-
ing assessed. Each case is unique.
The responsible for assessing people's competencies should devise an as-
sessment plan for each student, apprentice or trainee. Students and, where
appropriate, industry should be involved in the development of the assessment
plan. The plan should incorporate recognition of prior learning and any rea-
sonable adjustment that may be required.
Because work activities draw on the skills described in a number of units of
competency, teachers and trainers can use holistic assessment methods to
assess a range of units simultaneously.
Assessment can take place on the job or off the job. However, as applying
skills in the workplace is a key fact of VET, most evidence should ideally be
gathered as the student performs work duties, whether in the workplace or in a
simulated work environment.
What is meant by assessing a learner in a simulated work environment?
Simulation is a form of evidence gathering that involves the candidate com-
pleting or dealing with a task, activity or problem in an off-the-job situation that
replicates the workplace context. Simulations vary from recreating realistic
workplace situations such as in the use of flight simulators, through the crea-
tion of role plays based on workplace scenarios, to the reconstruction of a
business situation on a worksheet.
In developing simulations, the emphasis is not so much on reproducing the
external circumstance but on creating situations in which candidates are able
to demonstrate:
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1. Technical skills
2. Underpinning knowledge
3. Generic skills such as decision making and problem solving
4. Workplace practices such as effective communication.
Content within the range statement of each unit of competency in the relevant
training package will help the assessor determine the conditions of a valid
simulated work environment.
NOTE: In some instances a training package may state that certain compe-
tency standards can only be assessed in an actual workplace setting.
What is moderation?
Moderation is a process which involves assessors discussing and reaching
agreement about assessment processes and assessment outcomes in a par-
ticular industry or industry sector.
This process enables assessors to develop a shared understanding of the re-
quirements of specific training packages, including the relevant units of com-
petency and assessment guidelines, the nature of evidence, how evidence is
collected and the basis upon which assessment decisions are made to ensure
that assessments are valid, fair, reliable, and flexible.
There is no single model for moderation. Moderation involves assessors work-
ing in collaboration to review, compare and evaluate their assessment process
and their assessment outcomes, in relation to the same units of competency.
This includes validating assessment methods/tools, the evidence that was col-
lected using these assessment methods/tools and the interpretation of that ev-
idence to make a judgement of competence.
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There may be variation in assessors' judgments, but moderation works to en-
sure that the margins of variation are minimal.
The VET system is a national system, based on nationally developed qualifica-
tions and units of competency. Moderation is important to ensure that the out-
comes of these qualifications and units of competency are consistent.
This will assist to ensure that industry has confidence in the training and as-
sessment outcomes from the VET system.
Moderation also provides the opportunity for professional development of as-
sessors and the improvement of assessment products and services.
Range statement/range of variables
The range statement defines the boundaries within which a given unit of com-
petency and its associated performance criteria apply. By suggesting the
range of contexts and conditions, it also provides a focus.
The range statement can also be used to provide additional guidance and in-
formation to interpret the performance criteria. Many performance criteria use
words, terms or phrases that may mean different things in different contexts.
The performance criteria can’t list all these, but the words, terms or phrases
used in the performance criteria can be further defined or explained in the
range statement.
Evidence guide
The evidence guide helps you to interpret the assessment requirements of the
elements and performance criteria. It provides information about what evi-
dence can be used to demonstrate the defined competency.
15
The evidence guide includes any variables related to the assessment context
such as:
• conditions under which competency must be assessed including varia-
bles such as the assessment environment or necessary equipment
• relationships with the assessment of any other units of competency
• suitable methodologies for conducting assessment including the poten-
tial for workplace simulation
• resource implications, for example access to particular equipment, infra-
structure or situations
• how consistency in performance can be assessed over time, various
contexts and with a range of evidence
• critical aspects for assessment and evidence.
Graphically the assessment process can be seen as follows:
Certification
Verification of evidence
Judgement of evidence
Collecting of evidence
Generation of evidence
By the student
By the turor/assessor
By the internal/external verifier
By the awarding body
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In the following table different types of assessment methods and their possible uses are presented:
Assessment Type Possible Uses
Multiple Choice Measurement of a variety of learning outcomes such as vocabulary, facts, explana-tions and applications. Providing diagnostic assessment of entry behaviour or to as-sess objectives quickly at the end of a session.
Matching Block Testing of lower level knowledge (matching dates with events and symbols with units). When associations between things are to be identified, i.e. show or identify the right object/part on a table or picture or real object
Short Answer/ Com-pletion
When the learning outcome is to recall rather than to recognise information.
Structured and Ex-tended Essay
When the objectives specify writing or recall rather than recognition of information. When the sorting and presenting of an argument is required.
Practical When the assessment of skills is necessary
Self Assessment Especially useful for adults where affective and high level cognitive assessment is re-quired.
Profile For recording on-going assessment during a course to give and negotiate specific feedback to students.
Observation Particularly for psychomotor and affective domain objectives, like competences.
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As shown in the table above the different types of assessments can prove
useful in different situation based on what exactly we want to asses.
Bloom’s revised taxomony (English)
According to the revised version of Bloom’s Taxonomy there are six levels of
cognitive learning. The levels remembering, understanding, applying, analyz-
ing, evaluating, and creating are all conceptually different.
Remembering Recalling information
Recognising, listing, describ-ing, naming, finding
Understanding Explaining ideas or concepts
Interpreting, summarising, paraphrasing, classifying, ex-
plaining
Applying Using information in another
familiar situation Implementing, carrying out,
using, executing
Analysing Breaking information into
parts to explore understand-ings and relationships
Comparing, organising, de-constructing, interrogating,
finding
Evaluating Justifying a decision or course
of action Checking, hypothesising, cri-
tiquing, experimenting, judging
Creating Generating new ideas, prod-
ucts, or ways of viewing things Designing, constructing, plan-
ning, producing, inventing.
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Taxonomiestufen nach Bloom (German)
Nach der überarbeiteten Version der Bloom's Taxonomy gibt es sechs Ebenen
des kognitiven Lernens. Die Ebenen, die sich erinnern, verstehen, anwenden,
analysieren, bewerten und erschaffen, sind alle konzeptionell unterschiedlich.
Erinnern Abrufen von Informationen
Erkennen, Auflisten, Beschreiben, Benennen, Finden, Benennen, Auf-
finden
Verstehen Erläuterung von Ideen / Konzepten Interpretieren, Zusammenfassen,
Umschreiben, Klassifizieren, Erklä-
ren
Anwenden Verwendung von Informationen in einer anderen vertrauten Situation Implementierung, Durchführung,
Verwendung, Nutzung, Ausführung
Analysieren Brechen von Informationen in Teile, um Verständnis und Beziehungen
zu erforschen. Vergleichen, Organisieren, Dekon-
struieren, Verhören, Finden
Evaluieren Begründung einer Entscheidung
oder Vorgehensweise Überprüfen, Hypothesen stellen,
Krümmen, Experimentieren, Urtei-len, Beurteilen
Erschaffen Generierung neuer Ideen, Produkte
oder Sichtweisen auf die Dinge Entwerfen, konstruieren, planen,
produzieren, erfinden.
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Taxonomia revizuita a lui Bloom (Romanian)
Versiunea revizuita a taxonomiei lui Bloom descrie sase capacitati ale invata-
rii cognitive. Aceste capacitati conceptional diferite sunt: amintirea, intelege-
rea, aplicarea, analiza, evaluarea si crearea.
(Re)Amintirea Reproducerea de informatii
Recunoastere, listare, reamintire, redare, identificare
Intelegerea Formarea intelesului
Interpretare, rezumare, reformulare, clasificare, deducere, exemplificare
Aplicarea Folosirea de informatii in alte situatii Implementarea, folosirea, executia
Analiza Desconpunerea unui concept si descrierea relatiei dintre parti si
intreg Compararea, organizarea, des-
compunerea, diferentierea, atribui-rea
Evaluarea Motivarea unei decizii
Verificarea, crearea de ipoteye, ex-periemntarea, analiza critica
Crearea Generarea de idei, produse sau perspective noi asupra lucrurilor Generare, planificare, producere,
descoperire
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Taxonómia kognitívnych vzdelávacích cieľov podľa Blooma (Slovak)
Podľa prepracovanej verzie Bloomovej Taxonómie existuje 6 úrovní kognitív-
neho procesu. Sú to: pamätať, porozumieť, aplikovať, analyzovať, ohodnotiť a
tvoriť. Tieto úrovne sú konceptuálne rozdielne.
Pamätať Vyvolanie informácie
Rozpoznať, rozpísať, opísať, pome-
novať, nájsť.
Porozumieť Vysvetlenie myšlienok / konceptov Interpretovať, sumarizovať, opísať,
klasifikovať, vysvetliť.
Aplikovať Použitie informácií v inej, ale zná-
mej situácií Implementovať, uskutočniť, použiť,
vykonať.
Analyzovať Rozloženie informácií na časti, s cieľom skúmať porozumenie a
vzťahy. Porovnávať, organizovať, rozobe-
rať, vypočúvať, nachádzať.
Ohodnotiť Odôvodnenie rozhodnutia alebo
postupu Overiť, vytvárať hypotézy, experi-
mentovať, (po)súdiť
Tvoriť Vytváranie nových myšlienok, pro-
duktov alebo náhľadov na veci Navrhnúť, skonštruovať, plánovať,
produkovať, vynájsť.
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Example assesment method: worksheets
Topic: Fuel Cell
In this example, the module has been developed according to the ToT (Train-
ing of Trainers) manual.
1. action-oriented
2. with worksheets
3. with result sheets
4. with a lesson consisting of Learning Outcomes LOs, and Assessment
The "alternative energies" are a current topic of the energy industry.
The alternative wind and solar energy, however, cannot yet cover the entire
energy supply
The currently available energy sources of petroleum and natural gas will be
exhausted in about 60 years, the main energy sources of coal can still be used
for around 200 years and the uranium deposits have already been consumed
in 40 years.
For 20 years, the sun and the wind have been increasingly used as a source
of energy, but the problems of storage have not yet been solved with these
energies.
Practical experiments on the understanding of fuel cell technology are carried
out step by step in 7 worksheets.
22
Planning the module
1. Information
The physical principle of a fuel cell is easy to understand and consists of only
3 elements.
H
An anode A
A cathode B O
And an electron membrane C
The anode and cathode are made of metal (coated with platinum). The mem-
brane consists of a 0.1 mm thick plastic film, which separates the anodes gas-
tight from the cathode.
The fuel is hydrogen (combustible gas), the hydrogen "H" is supplied to the
anode, the oxygen "O" of the cathode. On the platinum-coated anode the hy-
drogen is split into the proton H + and the electron e. The positive proton can
migrate through the membrane to the negative cathode and connect there with
the oxygen to form H2O (water).
The electrons accumulate at the anode and, with a sufficient amount of elec-
trons, the charge will be sufficient to produce a voltage difference to the oppo-
site cathode such that a current flows from A to B.
This current is sufficient to operate an electric motor.
23
This process can be reversed by using the fuel cell to produce hydrogen (H +)
from water (H2O). In this operation, one speaks of an electrolyzer.
The core statement of fuel technology is:
A. If hydrogen is added to the anode of a fuel cell 2H2, electrical energy
can be generated.
B. If a voltage (for example the voltage of solar cells) is applied between
the cathode and the anode of a fuel cell, water (H2O) can be separated
into hydrogen (H2) and oxygen (O). In this case one speaks of an elec-
trolyzer.
24
2. Teaching materials are provided:
solar cells
fuel cells
25
Instruction plan for the fuel cell module
Estimated duration approx. 10 hours
Trainer: Date: Place:
Module: Alternative
energies
Topic / Project: Solar
Cell / Fuel Cell
Task: Record and evaluate
characteristics
Brief description of the target group
The module can be used for an in-plant training or as a module in the train-
ing.
Precondition is the measurement of current and voltage with the multimeter
and the knowledge of the program Office / Excel.
Module description:
This module serves to understand the function and importance of the fuel
cell as an energy carrier and energy generator.
In this module, electrical circuits are set up to carry out measurements on
solar cells, electrolyzers and fuel cells.
The handling of small volumes of hydrogen (5 to 100 cm3) is safe.
LO1: The production of solar power
Contents:
Measuring current and
voltage of the solar
cell;
Determine the charac-
Method / Media:
The mode of operation
of a solar cell,
Create tables and
graphs using Excel;
Resources / Material:
Multimeters, solar cells
Worksheets 1 to 3
26
teristics of the solar
cell.
Calculate the efficien-
cy
The measurements
and exercises are car-
ried out in groups
LO2: Function and characteristics of the electrolyzer
Contents:
Generation of hydro-
gen
Record the character-
istic
efficiency
Method / Media:
Understand the func-
tion of the electrolyzer
through experimenta-
tion
Create tables and
graphs using Excel;
The measurements
and exercises are car-
ried out in groups
Resources / Material:
Multimeter, electrolysis,
Worksheet 4 and 5
LO3: Function and characteristics of the fuel cell
Contents:
Collect the character-
istics,
Efficiency determine
power generation with
the fuel cell
Method / Media:
Experiment with the
fuel cell
Create tables and
graphs using Excel;
The measurements
and exercises are per-
formed and evaluated
in groups
Resources /Material:
fuel cell,
Worksheet 6 and 7
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LO4: Use the fuel cell as an electrical energy source
Contents:
Connect the consumer
to the fuel cell
Method / Media:
Experimentation in
groups
Resources / Material:
fuel cell,
electrical direct current mo-
tors
Assessment:
After the specified
worksheets 1 to 7
measurements have to
be carried out, results
have to be document-
ed, calculations have
to be carried out and
characteristics have to
be created with the
program Excel. The
results are stored in
the form of tables and
formulas (Excel
sheets)
The results are pre-
sented, interpreted
and evaluated.
Each member of the
group individually de-
clares its results in
their meaning.
Performance Criteria:
The tables and the re-
sults from the experi-
ments are evaluated
qualitatively according
to the> standards of
the given worksheets.
The test results are
the results of the
group.
Individual services are
determined in an oral
interview.
The competences are
observed during the
test and recorded in a
matrix.
Range Statement:
The measurements (exper-
iments) can be performed
in a laboratory or in a
classroom.
The materials are provid-
ed. A PC / group is availa-
ble.
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3. The worksheets are attached
worksheets 1 to 3 solar cells
worksheet 4 experiment with the electrolyzer
worksheet 5 Determine the efficiency of the electrolyzer
worksheet 6 experiment with the fuel cell
worksheet 7 Determine the efficiency of the fuel cell
29
Worksheet 1
Construction of the circuit:
Install the circuit as shown in the diagram below.
30
Worksheet 2
Execution of the experiment:
Use the resistor decade to set the resistances in the following table and
measure the voltage and current. Measure short-circuit current and open-
circuit voltage.
Calculate the respective power P = U ∙ I
R/Ohm U/V I/mA P/mW
∞
330,00
220,00
100,00
33,00
10,00
3,30
1,00
0,33
0,10
0,00
31
Use the measured value table to plot the dependency of the current on the
voltage graphically:
Isc = ____ mA Voc = ___ V
32
Worksheet 3
Determine the efficiency
Graph the performance as a function of voltage:
The point of the maximum output electric power is an extreme point of the
power curve. It is located where the product of voltage and current is the larg-
est: PMPP = UMPP ∙ IMPP
In this example, it is: PMPP = ____ V ∙ ____ A = ____ W
Calculation of the efficiency:
The efficiency η can be calculated with the measured values and the data of
the solar cell.
SolarModul:
Pmax = 1000 W/m2
UMPP= 2V
Ikmax = 380 mA
ModulFläche: 4 Zellen 25mm x 50 mm, A = 5 10-3 m2
33
The efficiency η is defined as the ratio of the irradiated power Pin and the elec-
trical power Pout delivered by the solar cell at the point of maximum power.
The short-circuit current is proportional to the irradiated light output.
The short-circuit current must be multiplied by a factor to obtain a quantitative
estimate of the light output. This factor depends on the maximum value
Of the short-circuit current of the solar cell. The factor F is calculated accord-
ing to the following formula:
For the calculation, use the following formulas:
34
Worksheet 4
Current-voltage characteristic of the PEM electrolyzer
Background:
The PEM electrolyzer decomposes water into hydrogen and oxygen, but the
voltage applied to the electrolyzer must exceed a certain value, the decom-
position voltage of the water. No decomposition occurs below this voltage.
In the following experiment we will investigate how large this voltage is.
Materials:
• PEM electrolyzer
• Power supply
• PEM fuel cell
• Circuit board with resistor decade
• Amperemeter
• Voltmeter
• Various cables with plug-in connectors
• Distilled water for refilling the PEM electrolyzer
35
Construction of the circuit:
Install the circuit as shown in the diagram below.
36
Execution of the experiment:
Use the power supply to adjust the voltages in the table and measure the cor-
responding current.
U/V I/A
0,0
0,5
1,0
1,2
1,3
1,4
1,5
1,6
1,7
1,8
1,9
2,0
37
Use the measured value table to graphically depict the dependency of the cur-
rent on the voltage:
After the decomposition voltage U = 1.5 V has been reached, the current rises
very sharply.
Never operate the electrolyzer or the reversible fuel cell more than 2 volts!
38
Worksheet 5
Efficiency of the PEM electrolyzer
Background:
In the electrolyzer, the electrical energy supplied is converted to hydrogen.
The calorific value of hydrogen HH2 indicates the amount of energy that can
be used for a combustion of 1 m3 of hydrogen. The following characteristic
values and formulas are known for determining the efficiency of the electrolyz-
er:
Efficiency η:
Benefit energy:
Eout = VH2 ∙ HH2
Energy input:
Ein = U∙I∙T
Remarks:
Heizwert HH2 = 10,8 106 𝐽
𝑚3
39
Required equipment and materials:
• PEM fuel cell
• Syringe
• Amperemeter
• Voltmeter
• Various cables with plug-in connectors
• distilled water
Construction of the circuit:
40
Execution of the experiment:
Switch on the lab power supply and select a voltage of U = 1,8 V.
VH2/cm3 t/s U/V I/mA
0
1
2
3
4
5
Display the measurement series in a diagram.
41
Calculate the efficiency of the electrolyzer. Use the specified characteristic
values and formulas as well as your table values.
HH2 = calorific value of the hydrogen = 10.8 106
VH2 = generated amount of hydrogen in m3
U = mean value of the voltage in V
I = mean value of the current in A
T = time in s
42
Worksheet 6
Current-voltage characteristic and power curve of the PEM fuel cell
Background:
In the fuel cell, the hydrogen and oxygen supplied from the outside react to
water, this being done by supplying electricity and heat. The power of the fuel
cell depends on the load resistance.
In the following experiment, the aim is to investigate the resistance and current
strength of the power output.
Required equipment and materials:
• PEM fuel cell
• Resistance decade
• Amperemeter
• Voltmeter
• Various cables with plug-in connectors
• distilled water
• Hydrogen source
43
Implementation:
Connect the electrolyzer to the power source to produce hydrogen and oxy-
gen. Produce. 5 cm3 of hydrogen gas. Start the tabulated recording of the cur-
rent-voltage characteristic with the open-circuit voltage (R = ∞.). Switch the
resistor decade from larger to smaller resistors and write down the voltage and
current values. Wait 10 seconds between each measurement for representa-
tive results.
R/Ohm U/V I/mA P/mW
∞
330,00
220,00
100,00
33,00
10,00
3,30
1,00
0,33
0,10
44
Evaluation:
Display the voltage-current characteristic in a diagram.
Display the power-current characteristic in a diagram.
45
Worksheet 7
Efficiency of the PEM fuel cell
Background:
The efficiency η provides a statement about the efficiency of energy convert-
ers and can assume values between 0 and 1 or in percent notation values be-
tween 0% and 100%. The greater the efficiency, the more efficient the tech-
nical system. In the following experiment, the efficiency of the fuel cell is de-
termined. The required quantities for calculating the energy (hydrogen) and
the useful energy (electric current) are provided by the test. Use the following
formulas and characteristic values to determine the efficiency:
Efficiency η:
Benefit energy:
Eout = U ∙ I ∙ t
Energy input:
Ein = VH2∙ HH2
46
Remarks:
Calorific value
HH2 = = 10,8 106 𝐽
𝑚3
Required equipment and materials:
• PEM fuel cell
• Resistance decade
• Amperemeter
• Voltmeter
• Various cables with plug-in connectors
• distilled water
• Hydrogen source
Construction of the circuit:
47
Carrying out the experiment:
t/s VH2/cm3 U/V I/mA P/mW
0
60
120
180
Mittelwert
Calculate the efficiency η.
48
Solutions to the experiments
Current-voltage characteristic, power curve and efficiency of the solar module
Sample solution for the trainer
U/V I/mA P/mW
2,3 9,6 22,2
2,3 10,8 24,8
2,3 23,0 51,8
2,2 33,4 73,5
2,1 52,5 110,3
2,0 73,3 146,6
1,8 107,5 193,5
1,6 140,0 224,0
1,0 191,0 191,0
0,0 195,0 7,8
49
Isc = 195 mA Voc = 2,33 V
50
Calculation of the efficiency:
Complete the table:
Peak power Pmax
224
mW
Open-circuit voltage Voc 2,33 V
Short-circuit current Isc 195 mA
Current at maximum
power Impp 140 mA
Voltage at maximum
power Vmpp 1,6 V
Modul efficiency 12 %
51
Current-voltage characteristic of the PEM electrolyzer
Sample solution for the trainer
U/V I/A
0 0
0,5 0
1 0
1,2 0,01
1,3 0,01
1,4 0,02
1,5 0,07
1,6 0,31
1,7 0,66
1,8 0,98
1,9 1,2
2 1,46
52
Efficiency of the PEM electrolyzer
Sample solution for the trainer
VH2/cm3 t/s
0 0
1 25
2 45
3 60
4 75
5 90
53
U = 1,9 V
I = 0,49 A
VH2 = 5 10-6 m3
t = 90 s
HH2 = Calorific value of the hydrogen =
HH2 = Calorific value of the hydrogen = 10,8 106 𝐽
𝑚3
VH2 = Generated amount of hydrogen in m3
U = Mean value of the voltage in V
I = Mean value of the current in A
t = Time in s
54
Current-voltage characteristic and power curve of the PEM fuel cell
R/Ohm U/V I/mA P/mW
∞ 0,94 0,00 0,00
330,00 0,93 0,80 0,74
220,00 0,91 4,70 4,28
100,00 0,89 8,50 7,57
33,00 0,84 22,60 18,98
10,00 0,78 55,70 43,45
3,30 0,70 94,10 65,87
1,00 0,69 130,00 89,70
0,33 0,52 140,00 72,80
0,10
0,00
55
56
Efficiency of the PEM fuel cell
t/s VH2/cm3 U/V I/mA P/mW
0 5 0,74 150 111,0
60 4
120 3
180 2 0,59 120 70,8
Average 0,67 135,00 90,9
