Download Highly efficient digitally-controlled AC-DC Converter

Faculty of Engineering
List of Experiment / Activity
Department:
Electrical and Computer Engineering
S/N
Location/Project
1
Location: Location: WS2-05-10
Electrical Machines and Drives Lab
Project : Highly Efficient Digitally
Controlled AC-DC Converter with PFC
Capability And Output Voltage
Regulation
[RS : Lim Shu Fan]
[PI: A/P Ashwin M. Khambadkone]
Last updated: 29 Feb 2008
Lab Supervisor
Work Experiment / Activities (Routine /
Non-Routine)
Building and testing of AC-DC converter
A/P SK Panda
Priority
Normal
Target Date for
Assessment
Ready to
assessment
Faculty of Engineering
Activity Sequence List - Activity or Experiment-Based Risk Assessment
Experiment / Activity Steps
Department:
ECE
No.
Experiment / Activity
1
Building and testing of AC-DC
converter
Location:
WS2-05-10
Laboratory:
Electrical Machines and Drives Lab
Workable Sequence/Task
Solder components to build AC-DC converter
Connect the converter to the AC and DC power supplies
Turn on the power supplies to the converter
Switching load for generating transients for functional verification
Faculty of Engineering
Activity or Experiment-Based Risk Assessment Form
Department:
ECE
Name of Experiment/Activity:
Building and testing of AC-DC converter
Location:
WS2-05-10
Name of Person in-charge:
Lim Shu Fan
Last Review Date:
29 June 2009
Next Review Date:
29 June 2012
1. Hazard Identification
No.
1
Task
Solder
Hazards
Mishandling
Possible
Consequences
Burns
is allowed to do
build AC-DC
soldering
Toxic
lung problem
 Smoke absorber
S
L
R
1
1
1
2
1
2
1
1
1
1
2
2
 Use the lead free
solder
2
Connect the
Over current / short
converter to the
circuit
Burns
External On / OFF
switch, circuit
AC and DC power
breakers trip
supplies
3
Turn on the
power supplies to
the converter
Over Current
Over heating
Burns
 Limit the
maximum current
in the power
supply control
panel
 To avoid large
current transients
in DC power
Last updated: 29 Feb 2008
A/P Ashwin M. Khambadkone
2. Risk Evaluation & Control
Existing Risk
Control
(if any)
Only trained person
components to
converter
Name of PI:
Additional /
New Risk
Control
S
L
R
Action By
Deadline
Faculty of Engineering
supplies,
increase the
voltage slowly to
the desired value
 Use external fan
to dissipate the
heat in the
semiconductor
devices
Current leakage
Burns
Ensure all earths
1
2
2
1
2
2
and terminals are
good, RCCB trips
4
Switching load for
Over Current
Burns
Limit the maximum
generating
current in the
transients for
power supply
functional
control panel
verification
Note: Please refer to the attached SOP for details
Conducted by: (Name, designation)
Lim Shu Fan (RS),
A/P Ashwin M. Khambadkone
Signature:
Date:
Approved by: (Name, designation)
A/P Ashwin M. Khambadkone
(Project supervisor)
Signature:
29 Sept 2009
Date:
29 Sept 2009
Risk Assessment Matrix
Likelihood
Severity
Minor
Moderate
Major
Remote (1)
Occasional (2)
Frequent (3)
1
2
3
2
4
6
3
6
9
(1)
(2)
(3)
Severity Categories
Level
Human (Impact to
Physical Being)
Biological Impact
Environmental
Damage
Property Damage (S$)
(1) Minor
No Injury or light injury
requiring only first aid
treatment (MC < 4 days
MC)
Any injury/ill health
leading to ≥ 4 days MC or
≥ 1 day hospitalisation or
leads to temporary
disability
May not cause human disease, if does, the disease
is unlikely to spread to the community and there is
usually effective prophylaxis or treatment available;
Reversible
Up to $5,000
Can cause severe human disease, not ordinarily
spread by casual contact from one individual to
another; it may spread to the community, but there
is usually effective prophylaxis or treatment
available
Reversible but takes
years
$5,001 to $50,000
Fatality, permanent
Disability or life
threatening disease
Can cause lethal human disease, may be readily
transmitted from one individual to another, or from
animal to human or vice-versa directly or indirectly,
or casual contact, it may spread to the community;
usually no effective prophylaxis or treatment
available
Irreversible
More than $50,000
(2) Moderate
(3) Major
Likelihood Categories
Level
(1) Remote
(2) Possible
(3) Frequent
Events Frequency
Undesired event which may occur but unlikely, once in 5 years
Undesired event which is probable, once in a year
Undesired event which probably occur in most circumstances, once or more in a month
Risk Level and Acceptability Criteria
Risk Score
Risk Level
Acceptability
of Risk
<3
Low Risk
Acceptable
3–4
>4
Medium Risk
High Risk
Last updated: 29 Feb 2008
Moderately
Acceptable
Not Acceptable
Recommended Actions
No additional risk control measures required. To continue to monitor to ensure risk do not escalate to higher level.
Acceptable to carry out the work activity; however, task need to be reviewed to bring risk level to As Low As Reasonably
Practicable.
Interim control measures such as administrative controls can be implemented. Supervisory oversight required.
Job must not be carried out until risk level is brought to at least medium risk level.
Faculty of Engineering
Risk controls should not be overly dependant on personal protective equipment. Controls measures should focus on
Elimination, substitution and engineering controls.
Immediate Management intervention required to ensure risk being brought down to at least medium level before work can
be commenced.
Safe Operating Procedure (SOP)
Project : Highly Efficient Digitally Controlled AC-DC Converter with PFC
Capability and Output Voltage Regulation
Name : Lim Shu Fan
e-mail : [email protected]
Tel : 6516-5257 / 6516-2106
Turn on setup
1. Make sure that the external switches connecting the eload and AC source to the DUT are off.
2. Switch on the main power to the DC source, eload and the AC source.
3. Turn on the power of DC source, eload, and AC source with output/input off.
4. Tune the eload (mode CC) and AC source (mode AC) with the required settings of voltage,
frequency and current with output/input off.
5. Turn on the external switches connecting the eload and AC source to the DUT.
6. Turn on the output of the DC source.
7. Tune the DC source to above 12.5V.
8. Turn on the output of the AC source.
9. Turn on the input of the eload.
Changing load setup
1. Press the knob once to enter the resistance setting mode.
2. Key in required resistance value.
3. Press ENT key.
Remember to increase or decrease the resistance in small steps to avoid voltage and current
overshoot or undershoot.
UNR refers to unregulated state and can be removed once Vin/Iin=R.
Changing input AC voltage
1. Turn off the output of the AC source.
2. Press V key to enter voltage setting mode from the home position.
3. Key in the required voltage value and press ENT to confirm.
4. Press ESC key to exit voltage setting mode.
5. Turn on the output of the AC source.
To protect the load, it is recommended that the output voltage be set with OUTPUT OFF.
Turn off setup
1. Turn off the output of the AC source.
2. Tune the DC source to 0V.
3. Wait till the Vout across bulk capacitor to discharge across the eload resistance till 0V.
4. Turn off the output of the eload.
5. Turn off the external switches connecting the eload and AC source to the DUT.
6. Turn off the output of the DC source.
7. Turn off the power of the AC source, eload and the DC source.
8. Switch off the main power to the AC source, eload and the DC source.
June 2009