Solar Energy Technology Science Summer Camp Session 9: Fri 9:00 AM - 12:00 N : Field trip to Energy...
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Transcript of Solar Energy Technology Science Summer Camp Session 9: Fri 9:00 AM - 12:00 N : Field trip to Energy...
Solar Energy TechnologySolar Energy TechnologyScience Summer CampScience Summer Camp
Session 9: Fri 9:00 AM - 12:00 N : Field trip to Energy Masters and
Installing/Commissioning the System
Day 3 Introduction Day 3 Introduction
• Description of Facilities – if needed
• Go Over Day 2 and rest of Course
• Handout Notes
• Review Safety Rules Safety Rules
– Safety first– Always follow safety rules
Session 9 TopicsSession 9 Topics
• Installing the System (Instructor TBD)– Utility Interconnection– Permitting and Inspection. Details of Role
Inverters
• Commissioning, Maintenance, and Troubleshooting
• Activities:
33
Getting Up and Running, Maintenance and Trouble shooting• Utility Interconnection
• * Permitting and Inspection. Details of Role Inverters
• * Commissioning, Maintenance, and Troubleshooting
• * Activities:
PV System Design and Installation
LO 10 Performance Analysis and Troubleshooting
Task/Skill
10.1. Describe typical system design errors
10.2. Describe typical system performance problems
10.3. Associate performance problems with typical causes
10.4. List equipment needed for typical system performance analysis
10.5. Compare actual system power output to expected
10.6. Identify typical locations for electrical/mechanical failure
Performance Analysis and Troubleshooting(7% of test questions)
Overall PV System Efficiencies
PV Array Input (DC) = 70 to 80%
AC Output (AC)
Reference 2
Typical Design Errors
General Issues
1. Not accounting for shading issues (trees, chimneys, inter-row spacing, etc.)
2. Inadequate structural support (wind, snow, seismic and dead loads)
Inverter Issues
1. Under/oversizing PV array relative to inverter capacity
2. Too many modules in a string (Voc x Temp Correction < Max Inverter DC input)
3. Too few modules in strings (Vmp with temp correction to make sure that do not drop below inverter cut-off voltage)
4. Under sizing wires for voltage drop (see voltage drop formula)
NEC Issues
1. Under sizing overcurrent protection devices (Isc - fuses and circuit breakers)
2. Under sizing wires for ampacity requirements (Isc – wire sizes, conduit fill and temperature correction factors, etc.)
3. Equipment labeling
Performance Analysis and Trouble Shooting Tools
1. Basic tool kit (screw drivers, etc)
2. Irradiance meter
3. Multimeters
DC Voltage
DC Current (Clamp-on / Hall Effect)
AC voltage (RMS)
AC current (RMS)
4. Hydrometer (battery systems)
PV System Problems from 1000 Solar Roof Project in Germany
Reference 2
Check Site Conditions
1. Module Condition
2. Array Condition
3. Roof condition
4. Array Shading
5. Inverter Condition (error messages, signs of charring, unusual noises, hot spots)
6. Wiring (connections, insulation abrasion, discoloration)
Check Performance
Inverter Efficiency = Displayed AC Power
Array Imp x Array Vmp
Array IV Curve
1. Take irradiance temperature and measurement.
2. Apply correction factors3. Measure Isc (current) and Voc (voltage)
being produced by the array4. Compare theoretical to practical
Check for Ground Faults
1. Possible signs
2. Voltage-to-ground from PV module frames, rack, inverter and other equipment.
3. Blown Ground Fault Fuse (> 1 amp fault)
4. Error code (minor fault)
5. Isolate and test individual module strings
Causes
Reference 3
1. Loose, broken or pinched wires
2. Loose connections
3. Rodent damage
Current Paths
Ground Fault Protection
Normal Operation
Current Paths
Positive Ground Fault
Current Paths
Negative Ground Fault