OPERATION MAINTENANCE OF A Japen Gor
SOLAR PV PLANT
APPROACHES TO O & M
Approaches
Corrective Preventive Predictive
O&M PARTS
Solar PV Field/ plant monitoring
Energy Generation monitoring
Fault occurrence data recording on daily basis
Replacement of the faulty parts
Solar PV module cleaning
Drawing records of each equipment
Maintenance of earthing Systems
Plant management, billing of energy, etc
Vegetation and Gardening
Water drainage management
TOPIC : OPERATION & MAINTENANCE
CHALLENGES
Cleaning time before 11 AM and after 5 PM
Plant monitoring in night hours
Auxiliary consumption of the plant must be
<1% for ground mounted plants
<0.25% for rooftop solar PV
Guarantee & Warranty of equipments
Degradation of PV modules should be <1%/Annum
Find out Mismatch loss
Metering
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TOPIC : OPERATION & MAINTENANCE
ASPECTS OF O&M
Electrical
Mechanical
O&M
Civil
Communication
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TOPIC : OPERATION & MAINTENANCE
DC SYSTEM
PV Module
String Junction Box
DC Cable
Inverter
DC Disconnector
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MAINTENANCE OF A PV PLANT
Compared to most other power generating technologies, Pv plants have low
maintenance and servicing requirements. However, suitable maintenance of a Pv plant
is essential to optimise energy yield and maximize the life of the system.
Maintenance consists of:
Scheduled or preventative maintenance – planned in advance and aimed to prevent
faults from occurring, as well as to keep the plant operating at its optimum level.
Unscheduled maintenance – carried out in response to failures.
SCHEDULE MAINTENANCE
Module cleaning.
Checking module connection integrity.
Checking junction / string combiner boxes.
Thermographic detection of faults.
Inverter servicing.
Inspecting mechanical integrity of mounting structures.
vegetation control.
Routine balance of plant servicing / inspection
UNSCHEDULED MAINTENANCE
Tightening cable connections that have loosened.
Replacing blown fuses.
Repairing lightning damage.
Repairing equipment damaged by intruders or during module cleaning.
Rectifying supervisory control and data acquisition (SCADA) faults.
Repairing mounting structure faults.
Rectifying tracking system faults.
1. MODULE CLEANING
Module cleaning is a simple but important task. It can produce significant and
immediate benefits in terms of energy yield.
The frequency of module cleaning will depend on local site conditions (for example,
prevalence of dust or rain) and the time of year.
As the soiling of modules is site – specific, the duration between clean-ups is likely to
vary between sites. However, it is generally recommended to clean the modules at
least twice annually. Figure 25 shows the solar panel covered with dust.
1. MODULE CLEANING
When scheduling module cleaning, consideration should be given to the following:
Environmental and human factors (for instance, autumn fall debris and soiling from
local agricultural activities).
Weather patterns: cleaning during rainy periods is less likely to be required.
Site accessibility based upon weather predictions.
Availability of water and cleaning materials.
1. MODULE CLEANING
2. MODULE CONNECTION INTEGRITY
Checking module connection integrity is important for systems that do not have string
level monitoring.
This is more likely for central inverter systems for which no string monitoring at the
junction/combiner boxes has been designed.
In such cases, faults within each string of modules may be difficult to detect.
Therefore, the connections between modules within each string should be checked
periodically (this may include measuring the string current
3. JUNCTION OR STRING COMBINER BOX
All junction boxes or string combiner boxes should be checked periodically for water
ingress, dirt or dust accumulation and integrity of the connections within the boxes.
Loose connections could affect the overall performance of the PV plant.
Any accumulation of water, dirt or dust could cause corrosion or short circuit within the
junction box.
Where string level monitoring is not used, periodic checks on the integrity of the fuses
in the junction boxes, combiner boxes and, in some cases, the module connection box
should be conducted.
4. HOT SPOTS
Potential faults across the PV plant can often be detected
through thermography. This technique helps identify weak and loose connections in
junction boxes and inverter connections.
It can also detect hot spots within inverter components and along strings of modules
that are not performing as expected.
Thermography should be conducted by a trained specialist using a thermographic
camera.
5. INVERTER SERVICING
Generally, inverter faults are the most common cause of system downtime in PV power plants.
Therefore, the scheduled maintenance of inverters should be treated as a centrally important part
of the O&M strategy.
The maintenance requirements of inverters vary with size, type and manufacturer. The specific
requirements of any particular inverter should be confirmed by the manufacturer and used as the
basis for planning the maintenance schedule
The annual preventative maintenance for an inverter should, as a minimum, include:
• Visual inspections.
• Cleaning/replacing cooling fan filters.
• Removal of dust from electronic components.
• Tightening of any loose connections.
• Any additional analysis and diagnostics recommended by the manufacturer
6. STRUCTURAL INTEGRITY
The module mounting assembly, cable conduits and any other structures built for the
PV plant should be checked periodically for mechanical integrity and signs of
corrosion.
This will include an inspection of support structure foundations for evidence of erosion
from water run-off
7. TRACKER SERVICING
Similarly, tracking systems also require maintenance checks.
These checks will be outlined in the manufacturers’ documentation and defined within
the warranty conditions.
In general, the checks will include inspection for wear and tear on the moving parts,
servicing of the motors or actuators, checks on the integrity of the control and power
cables, servicing of the gearboxes and ensuring that the levels of lubricating fluids
are suitable.
The alignment and positioning of the tracking system should also be checked to
ensure that it is functioning optimally. Sensors and controllers should be checked
periodically for calibration and alignment
8. BALANCE OF PLANT
The remaining systems within a PV power plant, including the monitoring and
security systems, auxiliary power supplies, and communication systems should be
checked and serviced regularly.
Communications systems within the PV power plant and to the power plant should
be checked for signal strength and connection.
9. VEGETATION CONTROL
Vegetation control and ground keeping are important scheduled tasks for solar PV
power plants since there is a strong likelihood for vegetation (for example, long
grass, trees or shrubs) to shade the modules.
The ground keeping can also reduce the risk of soiling (from leaves, pollen or dust) on
the modules.
TOPIC : OPERATION & MAINTENANCE
PV MODULES (UL RECOMMENDATION)
For any maintenance purpose
do not lift the module by grasping
the module’s junction box
or electrical leads
Do not stand or step on
the module
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Topic: Operation & Maintenance
PV MODULES (UL RECOMMENDATION)
Do not drop the module or allow objects to fall on the modules
To avoid glass breakage, do not place any heavy objects on the module
Be cautious when setting the module down on to a surface
Inappropriate transport and installation may break the module
TOPIC : OPERATION & MAINTENANCE 22
Topic: Operation & Maintenance
PV MODULES (UL RECOMMENDATION)
Do not attempt to disassemble
the modules, and do not
remove any attached nameplates
or components from the modules
Remove paint or adhesive
to the module top surface
TOPIC 23
Topic: Operation & Maintenance
PV MODULES (UL RECOMMENDATION)
To avoid damage to the back sheet, do not scratch or hit the back sheet
Do not drill holes in the frame. This may compromise the frame strength and cause
corrosion of the frame
Do not scratch the anodized coating of the frame (except for grounding connection).
It may cause corrosion of the frame or compromise the frame strength
TOPIC : OPERATION & MAINTENANCE 24
Topic: Operation & Maintenance
PV MODULES (UL RECOMMENDATION)
A panel with broken glass or torn back sheet cannot be repaired and must
not be used since contact with any panel surface or the frame can cause a
electric shock
Work only under dry conditions, and use only dry tools, Do not handle
panels when they are wet unless wearing appropriate protective equipment
When storing uninstalled panels outdoors for any period of time, always
cover the panels and ensure that the glass faces down to stop water from
collecting inside the panel and causing damage to exposed connectors
TOPIC 25
Topic: Operation & Maintenance
TOPIC : OPERATION & MAINTENANCE 26
Topic: Operation & Maintenance
SJB
➢Before starting inspection, Check the earthing of SJB and Wear insulating safety
materials, O&M person should check if SJB is not following defects
➢Broken, cracked, misaligned or torn external surfaces
➢Corrosion of any part of the component, inside or outside
➢Dust, water into the electrically active interior of the component loss of mechanical
integrity
➢Check the gaskets of the SJB.
TOPIC 27
Topic: Operation & Maintenance
SJB
Check the gland plates of the SJB one by one
Check the Cable glands of the SJB, if found loose then it needs to be tightened
Check the vermin proofing of the SJB, so that no insects, mice, and snakes can harm
SJB
Use thermal imager to find out hot spot and loose electrical connection in the SJB
The loose connection may burn the contact assembly and can generate other fatal
damages, the ractification of same should be done as early as possible
TOPIC 28
Topic: Operation & Maintenance
TOPIC : OPERATION & MAINTENANCE 29
Topic: Operation & Maintenance
SJB
Replace the protection fuses used for strings, If found blown away, to increase the
plant availability
Routine check the protection used for the SJB
TOPIC 30
Topic: Operation & Maintenance
CABLE
There are several standards needs to be followed IS 8130, IS
694, IS 5831, IS 7098, IS 3975,
IEC 60228-5, IEC-60332-1, IEC 61034,
IEC 60754-1, IEC 60216, IEC 60811,UL 4703
TOPIC : OPERATION & MAINTENANCE 31
Topic: Operation & Maintenance
CABLE
PV module cables are generally tied with ‘Cable tie’
The cable tie life span is very short and may get damage
shortly
Check and replace all damage cable tie so that cable may not
in hanging condition
Check cable insulation where it is exposed to sunlight
TOPIC 32
UNSCHEDULED MAINTENANCE
The majority of unscheduled maintenance issues are related to the inverters.
This can be attributed to their complex internal electronics, which are under constant operation.
Depending on the nature of the fault, it may be possible to rectify the failure remotely – this option is clearly preferable if
possible.
Other common unscheduled maintenance requirements include:
• Tightening cable connections that have loosened.
• Replacing blown fuses.
• Repairing lightning damage.
• Repairing equipment damaged by intruders or during module cleaning.
• Rectifying SCADA faults.
• Repairing mounting structure faults.
• Rectifying tracking system faults.
SPARE PARTS
In order to facilitate a rapid response, a suitably stocked spares inventory is essential. The
numbers of spares required will depend on the size of the plant and site-specific parameters.
Adequate supplies of the following components should be held:
• Mounting structure pieces.
• Junction/combiner boxes.
• Fuses.
• DC and AC cabling components.
• Communications equipment.
• Modules (in case of module damage).
• Spare inverters (if string inverters are being used).
• Spare motors, actuators and sensors should also be kept where tracking systems are used
O&M CONTRACTORS
It is common for the O&M of PV plants to be • Site substation.
carried out by specialist O&M contractors. The
contractor will be responsible for the operation • Site fencing and security system.
and maintenance of the whole plant. This is likely • Auxiliary power supply.
to include:
• Site access routes and internal site roads.
• Modules and mounting frames or tracking system.
• Site building and containers.
• Inverters.
• Vegetation control.
• DC and AC cabling.
• Maintenance of fire-fighting equipment or
• String combiner or junction boxes. reservoirs.
• Site SCADA system, remote monitoring and
communication systems.
PERFORMANCE OPTIMISATION STRATEGIES
PERFORMANCE OPTIMISATION STRATEGIES
