Control systems and telecommunications. Components and infrastructure needed to control systems Monitoring and troubleshooting Management of information obtained by the control system Management and alarms. Sending information for maintenance purposes. Security of the Installation. Fundamental characteristics required in a surveillance system. Protection systems against theft. Anti‐intrusion systems. CCTV and video surveillance. e‐Rounds. Remote control systems. Security in PV roofs.

1. Photovoltaic Systems Training
Session 3 ‐ Plant Operation
Javier Relancio & Luis Recuero
Generalia Group
September 21st 2010
http://www.leonardo-energy.org/training-pv-systems-design-
construction-operation-and-maintenance

2. PHOTOVOLTAIC SYSTEM
Design, Execution, Operation & Maintenance
PLANT OPERATION
Javier Relancio. Generalia Group. 21/09/2010
www.generalia.es
2
http://www.leonardo-energy.org/training-pv-systems-design-construction-operation-and-maintenance

3. INDEX
Control & Telecommunication system
Control system components & infrastructures
Control system gathered data management
Plant security
Security systems
3
http://www.leonardo-energy.org/training-pv-systems-design-construction-operation-and-maintenance

4. INDEX
Control & Telecommunication system
Control system components & infrastructures
Control system gathered data management
Plant security
Security systems
4
http://www.leonardo-energy.org/training-pv-systems-design-construction-operation-and-maintenance

5. Control & Telecommunication Systems:
Introduction
Monitoring:
To control, using specially designed devices,
the state & evolution of one or various
physiologic (or others) parameters to detect
possible malfunctions
Remote control:
Group of devices which allow us to modify the state of the equipments and devices of the
plant, from a remote location
Reasons for monitoring & control:
1.- To invoice the produced energy
2.- To detect incidences & malfunctions
a) Availability
3.- To guarantee the plant owner b) Performance Ratio
c) Production (kWh./kWp)
5

6. Control & Telecommunication Systems:
Introduction
This presentation is based in Grid Connected PV Facilities
Both the meters and the inverters have communications outputs to allow the monitoring
of their parameters
We can also use: calibrated cells, temperature sensors, etc
Energy Transformer
Photovoltaic DC / AC Meter
Array Inverter Electricity
Grid
The remote control and monitoring depend on the available mechanisms.
Both in grid connected and stand alone PV facilities, electronic devices with communication
ports and dataloggers are used in order to gather the information from the different
equipment more important parameters
6
http://www.leonardo-energy.org/training-pv-systems-design-construction-operation-and-maintenance

7. Monitoring System
The monitoring system features will depend on the capability for
each plant to afford its cost
Requirements:
Reliability: redundancy. Stable communications (wire)
Robustness: gathering errors, incidences & alarms
Solutions:
To be found in the market
Already developed.
From each manufacturer or generic (Many inverter & meter
manufacturers)
Customized solutions
They are more scalable and can be updated
7
http://www.leonardo-energy.org/training-pv-systems-design-construction-operation-and-maintenance

8. INDEX
Control & Telecommunication system
Control system components & infrastructures
Control system gathered data management
Plant security
Security systems
8
http://www.leonardo-energy.org/training-pv-systems-design-construction-operation-and-maintenance

9. PV Facility main elements
Element Parameters Incidences
Panels ‐ String current ‐ Module malfunctioning
‐ Irradiance ‐ Isolating error
Inverter ‐ Instant power ‐ Electronic failure (low
‐ Produced energy performance)
‐ CO2 Emissions ‐ Electric failure (stop)
Meter ‐ Produced kWh ‐ Meter stop
‐ Load profile
Transformer ‐ Phase voltage ‐ grid out of range
grid ‐ Frequency

10. Other elements within a PV facility
Element Parameter Alerts / Warnings
Calibrated cell ‐ Radiation ‐ Low production, when high
radiation
Meteo Station ‐ Wind speed ‐ High wind speed
‐ Temperature
Current sensors ‐ Current ‐ Overvoltage
‐ Voltage ‐ System breakdown
Protections ‐ State (ON / OFF) ‐ Trigger
http://www.leonardo-energy.org/training-pv-systems-design-construction-operation-and-maintenance

11. Monitoring System. Topology
Sensors Communications Control Room Alarms
Options: Server 1. Locals:
Siren
1.Data gathering
1. Design
2. SMS
2.Data Analysis
- Wire
3.Alert 3. E-mail
Inverter - Wireless
generation
Internet
Datalogger 2. Logic 4.Internet
RS232/485 - Without logic: communication
1. BBDD
Ethernet Converter 5.Logs
2. Web
Meter - With logic: 3. Tunnel
Datalogger 1. VPN
Display
RS232/485
Visualization 2. VNC
http://www.leonardo-energy.org/training-pv-systems-design-construction-operation-and-maintenance

12. Monitoring system: Routine
Data gathering & Analysis
Performance:
Performance: lightly Performance: lower than
average or
lower than average average
higher than
average
Failure
Parameter analysis Alarm
diagnosis
Actions/Modifications on the system
- In situ or by Remote control
Include modifications in - Report generation
preventive maintenance - Corrective maintenance order
Correct Incidences &
parameters log
12
http://www.leonardo-energy.org/training-pv-systems-design-construction-operation-and-maintenance

13. Remote control system. Basic topology
ON/OFF switches for system reclosing (i.e. in case of breakdown)
REMOTE PC
Tracker Control
INTERNET
Monitoring System
Gateway Server
Security system
13
http://www.leonardo-energy.org/training-pv-systems-design-construction-operation-and-maintenance

14. Remote control system. Advanced topology
An advanced remote control system requires larger bandwidth and robustness
- Updates
Tracker - Modifications
PC
REMOTO - Configurations
INTERNET - Updates
Monitoring - Modifications
system - Configuration
- New meters &
inverters
Gateway Server
- Updates
Security
- Modifications
System
- Configuration
14
http://www.leonardo-energy.org/training-pv-systems-design-construction-operation-and-maintenance

15. Communications
Internal communications
Data transference between devices, dataloggers, Server & Gateway.
Topology:
Wireless: Bluetooth, wifi, GSM/GPRS/UMTS, etc..
Wired: RS232, RS485, Ethernet, Optical Fiber, etc..
Converters’ usage: Moxa, etc..
External communications
To communicate remotely
Topologies: RTB, ADSL, Satellite, GSM/GPRS/UMTS…
Redundancy & robustness
15
http://www.leonardo-energy.org/training-pv-systems-design-construction-operation-and-maintenance

16. Communications
Telephone GPRS UMTS Radio Satellite
Network (PSTN)
Coverage
Bandwidth
Reliability /
Robustness
Cost
(Installing)
Cost
(Operation)
http://www.leonardo-energy.org/training-pv-systems-design-construction-operation-and-maintenance

17. Remote Meter Reading
(From the electrical company)
The electrical company remote meter reading, which is already being done in some countries,
as Spain, allows the electrical company (or the grid manager):
Avoid having dedicated staff to read the meter locally for invoicing
Receiving data from the meters, that well processed, can improve the grid performance
GSM Modem RS232/485
Meter BUS
Modem GSM
Server
Conversor
Gateway Gateway Ethernet – Meter BUS
RS232/485
Electrical company Generator
* In the future PLC communications could be applied
http://www.leonardo-energy.org/training-pv-systems-design-construction-operation-and-maintenance

18. Usual problems
Using the same system in different facilities
A system that works perfectly for a solar facility, may not work properly in a different one
due to different devices, SW versions, communication buses, countries, etc..
Solutions compatibility
Mixing commercial solutions from different manufacturers may produce system
malfunctions due to devices response times, transference times, bandwidths, etc..
Many solutions are still under development.
Coverage failure
Isolated areas. Without Telephone Network (PSTN), ADSL, UMTS or GPRS coverage
Losing the communication channel would mean losing 90% of the system features
18
http://www.leonardo-energy.org/training-pv-systems-design-construction-operation-and-maintenance

19. INDEX
Control & Telecommunication system
Control system components & infrastructures
Control system gathered data management
Plant security
Security systems
19
http://www.leonardo-energy.org/training-pv-systems-design-construction-operation-and-maintenance

20. Operation orientated monitoring
The most important device is the meter
It is the last device in the system. The one that meters the energy
Objective: injected to the grid
Maximize We have to control that we are injecting the maximum energy to the
productivity grid
We need references:
Radiation (calibrated cell) & temperature
Others: experience, reference facilities, etc
The inverter can help to prevent future malfunctions
Example: If the temperature is raising continuously, it could mean:
A sporadic technical failure – REPAIR
A design failure – REDESIGN
The plant could stop.
http://www.leonardo-energy.org/training-pv-systems-design-construction-operation-and-maintenance

21. Operation Key points
To detect incidences as soon as possible (Real Time)
To predict some incidences & breakdowns
To solve some incidences & breakdowns
To warn the staff in the plant
The local plant staff can NEVER be replaced by any software or remote
control
It is essential to have spare parts and equipments at the plant
High electrical risk: training and protections
21
http://www.leonardo-energy.org/training-pv-systems-design-construction-operation-and-maintenance

22. Operation orientated monitoring
Example: Valdecarábanos Solar Plant. Spain
http://www.leonardo-energy.org/training-pv-systems-design-construction-operation-and-maintenance

23. Remote control system
Used to remotely control the devices in the plant
Devices:
Inverter, suntracker, protections, monitoring system, security system
NEVER the meters
Reasons:
1. Save costs.
2. Legal requirement:
Requirement from the Electric Company: remote control of the
isolation cells (of the transformer)
Depending on each country regulations, the PV plants over a
certain output power could be obliged to be attached to a
generation control center
23 It will usually be linked with the monitoring system

24. Data sending for maintenance
Maintenance types
Corrective: to solve an incidence
Preventive: to prevent a possible incidence, before it happens.
Elements to maintain
Inverter
Suntracker
Panels (maintenance is required to a lesser extent): cleaning up,
replacement…
24
http://www.leonardo-energy.org/training-pv-systems-design-construction-operation-and-maintenance

25. Inverter maintenance
Failure classification:
According to its seriousness:
Warning: minor failures. Many warnings can be expected. Generally, not
important
Alarm: serious failures. They should be minimized. They are important, and
could imply the plant stop
According to its origin:
Internal: from the inverter
External: from the plant.
DC side: from the panels to the inverter.
AC side: from the inverter to the grid
25
http://www.leonardo-energy.org/training-pv-systems-design-construction-operation-and-maintenance

26. Inverter maintenance
Usual incidences:
Isolation failure (cable without enough protection)
External failure: from the plant.
Low DC Voltage:
External failure: AC side problem (in the modules array)
MPP Tracking failure
External failure: a wrong configuration could produce a
deviation from the MPPT
Internal failure: Programming/Firmware problem
Grid voltage or frequency out of range
External failure: from the inverter to the grid
Temperature limit
26
http://www.leonardo-energy.org/training-pv-systems-design-construction-operation-and-maintenance

27. Suntracking maintenance
Orientation/Position failure
To check if it is synchronized or not
In case of strong wind, to check if it is in
protection state or not
Motor overvoltage failure.
Reducer breakdown
Limiting movement sensor
Overpass the end charging sensors without
activating the stop signal
27
http://www.leonardo-energy.org/training-pv-systems-design-construction-operation-and-maintenance

28. INDEX
Control & Telecommunication system
Control system components & infrastructures
Control system gathered data management
Plant security
Security systems
28
http://www.leonardo-energy.org/training-pv-systems-design-construction-operation-and-maintenance

29. Security in the plant: Introduction
Reasons:
Expensive elements: inverters, panels, cable, etc
Many thefts
To avoid production losses (there are insurances which cover these losses)
Isolated areas
Long unattended periods (unless local staff is employed)
Great communication problems
The perfect solution does not exist.
But the best would be the combination of:
Local staff
Remote security systems
http://www.leonardo-energy.org/training-pv-systems-design-construction-operation-and-maintenance

30. Security in the plant: Possibilities
The possible security systems could be:
Local staff
Video surveillance system (CCTV)
Perimeter sensors
Panel sewing
String controllers
Infrared / Microwave controllers
The security systems keep evolving as the thieves develop new
techniques
http://www.leonardo-energy.org/training-pv-systems-design-construction-operation-and-maintenance

31. Security in the Plan: General scheme
Solar plant security system
Real time internet Real time mobile
access phone access
Acoustic &
Domo video Luminous
camera waning
Video analysis.
ADSL / Intrusion
GPRS detection
Night mode
Control video cameras
room
Optical Fiber Local authorities
warning system
Source: PYSEC Seguridad
http://www.leonardo-energy.org/training-pv-systems-design-construction-operation-and-maintenance

32. INDEX
Control & Telecommunication system
Control system components & infrastructures
Control system gathered data management
Plant security
Security systems
32
http://www.leonardo-energy.org/training-pv-systems-design-construction-operation-and-maintenance

33. Local staff (In the plant)
Advantage
Very dissuasive solution
Drawbacks
The most expensive solution (in the Long Term)
It may reduce the plant profitability
Options
Employees
Outsourcing
The optimal solution would be Local Staff & Video surveillance
http://www.leonardo-energy.org/training-pv-systems-design-construction-operation-and-maintenance

34. Video surveillance system
CCTV vs IP
CCTV
Closed TV Circuit
It requires dedicated
transmission buses
IP - based
Versatility
Good quality
Good transmission
Less wiring
Recommended: IP
Source: Condev
System

35. Video Surveillance System: elements
Digital Video Recorder (Encoder/Decoder)
D1 Real Time Quality
Great storage capacity D1 Quality
Optional:
- Full D1 video is 720x480.
Alarms & relays management - Cropped D1 is 704x480.
- Half D1 video is 352x480
Remote control
Video analyzer
Using specialized software
Expensive
Movement detection
http://www.leonardo-energy.org/training-pv-systems-design-construction-operation-and-maintenance

36. Video Surveillance System: elements
Video camera
They can be IP or analogical
Quality: Up to D1 (Real time)
Long distance(Several Km*)
Optical Zoom: 60x
Infrared
Long distance
Night viewing (when the risk is higher)
Range: 1.5Km (0.00001 lux).
PTZ Control
Automatic or Manual orientation & zoom control (Joystick).
* According to specs, up to 15 km.

37. Anti – Intrusion systems
Perimeter sensor system
Best solution: optical fiber system
Passive system: immune to storms or electrical
systems
False alarms discrimination
Alarm if the fiber is cut
Alarm if a movement is detected
Options:
At the wall. More vulnerable Movement/Passage
areas
Buried. More expensive (trench)
Temperature range: -30º to 75º
Rubber tube Metallic tube
http://www.leonardo-energy.org/training-pv-systems-design-construction-operation-and-maintenance

38. Anti-intrusion system
Presence sensor
Detects:
Infrared: thermal energy variations
Microwaves: movements
Configurable:
Alarm only if double detection
Problems in foggy areas
Alarm if any detection
False alarms
http://www.leonardo-energy.org/training-pv-systems-design-construction-operation-and-maintenance

39. Anti-theft system
Panel sewing (with optical fiber)
Attached to every panel (at the backside)
Alarm if the fiber is cut
Difficult execution
Temperature range: -30º a +75º
Another option could be a conductive wire system
Depending on the wire impedance
Immune to sabotage
http://www.leonardo-energy.org/training-pv-systems-design-construction-operation-and-maintenance

40. Anti-theft system
String Controller
Both for monitoring and security systems
During the days
It controls the power (Current/Voltage) on the panel strings
It protects the plant with integrated fuses
During the night
It detects if the electrical cable is cut/broken
Even if there is no voltage or current
This is quite a new system
http://www.leonardo-energy.org/training-pv-systems-design-construction-operation-and-maintenance

41. Alarm management
Local alarm:
Siren, Lighting, Speakers
Study the inputs
Dissuasive
-Plant visibility
-Distance to the
Local staff:
security entity
SMS, E-Mail, Phone call -Etc.
Two options:
To control, or to warn the authorities Siren
- Dissuasive: to
avoid being stolen
Warning the authorities: - To try to catch the
thief
Private entity or the public authorities
We have to consider the distance from the authorities to
the plant
http://www.leonardo-energy.org/training-pv-systems-design-construction-operation-and-maintenance

42. Other possibilities
Virtual patrols
Nowadays, a possibility that can mean an important saving in physical surveillance is the
called "virtual patrol“
The virtual patrol simulates an ordinary guard patrol, but it is done from a remote central
of the surveillance company using a system of video cameras
Security for rooftop facilities
Usually, for this type of projects, no surveillance system is installed but the ones already
used by the clients, as this facilities are normally located in urban zones.
If the facility is located in an isolated area and the roof is not very high or difficult to
access, it is recommended to apply one of the security systems described within this
presentation
It is also recommended to have the “all risk insurance” in force.
http://www.leonardo-energy.org/training-pv-systems-design-construction-operation-and-maintenance

43. End of Session 3
Thank you for attending
http://www.leonardo-energy.org/training-pv-systems-design-
construction-operation-and-maintenance
43