PV String Monitoring Solution
Electronic Cards for use in PV Combiner Box Applications
Mersen PV String Monitoring Solution
The goals of PV String Monitoring
– For the investor: to measure energy produced and forecasted
revenues
– For the operator: to detect defects for maintenance
 But most existing systems have huge limitations
• Precision is not good enough at inverter level
• Monitoring systems are proprietary
• Data interpretation is not easy
 Need for high quality universal monitoring systems
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Mersen PV String Monitoring Solution
The advantages of string level monitoring
– Detection of problems as soon as they appear
– Precise localization of problems in the PV installation
Pro-active maintenance
Optimized PV installation performance
Secured ROI, predictive revenues and reduced OPEX
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Mersen PV String Monitoring Solution
Performance Ratio
Monitoring of instantaneous
electrical parameters
Energy produced over time T
Performance Ratio =
Energy expected over time T
Monitoring of operating
conditions: T°, sun,…
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Mersen PV String Monitoring Solution
A precise control of the installation from the PV field to the
inverter
String Monitoring
in the combiner box
Communication Gateway
(GPRS, Ethernet, …)
2000
800,0
CurrentMean-PVString1
1800
CurrentMean-PVString2
700,0
CurrentMean-PVString3
1600
CurrentMean-PVString4
600,0
Pyranomètre
Ens Modbus
1400
Temp ext Modbus
Temp Cellule Modbus
1200
Monitoring
Software
Monitoring
Software
500,0
400,0 W/m²
°C
mA 1000
800
300,0
600
200,0
400
100,0
200
0
6:00
5
7:12
8:24
9:36
10:48
12:00
13:12
14:24
15:36
16:48
0,0
18:00
Mersen PV String Monitoring Solution
Product Offering
– Flexible, High Performance Solution
– Three Electronic Cards
• MAIN Card
• AUX Card
• PROBE Card
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Mersen PV String Monitoring Solution
Monitor 6 to 30 strings by connecting up to (4) AUX Cards to
the MAIN Card
Monitor up to 8 external inputs (7 analog + 1 digital) by
connecting the PROBE Card
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Diagnostic & control:
 4 digital inputs
 3 external relay control
Communication: MODBUS on
isolated RS485 (1.2km cable)
Aux Card extension:
 up to 4 Aux. cards in parallel
 6 strings monitored per card
 6, 12, 18, 24 or 30 strings can be
monitored by one single box
32bits microcontrollers
 Modbus Communication
 Measurement & data
processing
 16Mbit memory (6 months
data storage worse case)
Probe Card extension:
 1 digital sensor
 7 analog sensors:
• 4-20mA, ±1% precision
• 1-10V, ±1% precision
6 PV string inputs
 Max voltage: ± 1000 Vdc
 Max current: ± 25 A
 Precision:
± 0.5%
Autonomous power supply from PV strings
 250Vdc to 1000Vdc string voltage
 Low power consumption: 4W @1000Vdc
Reliable operating range
 -40°C to +70°C operating temperature
Integrated Bus Bar
 150A combined output (two output
 onboard temperature sensors (-40°C to +100°C ±2°C)
terminals, 75A each)
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Mersen PV String Monitoring Solution
Features and Benefits
– Built-in Power Supply – Take power directly from the PV string.
Eliminates the need to purchase and install a separate power
supply to power the monitoring device
– Accuracy – 0.5% precision
– Voltage and Current Measurement – Additional voltage
measurement provides a greater level of detail and is required by
some integrators
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Mersen PV String Monitoring Solution
Features and Benefits
– Flexible 6-String Device – Allows for greater flexibility (can be
configured for 6, 12, 18, 24 or 30 string boxes)
– Integrated Bus Bar – Combines strings into 1 or 2 outputs based
on ampere rating. Eliminates the need for separate comb bus bar
– Increased Functionality – Option to connect up to 8 external
sensors (anemometer, thermometer, sun sensor, etc…)
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Mersen PV String Monitoring Solution
Available Resources and Tools
ep-us.mersen.com
Installation Guide
Data Sheet
Tech Topics
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PowerPoint
PROBE Card
MAIN Card
ep-us.mersen.com
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AUX Card