Embed Size (px)
Citation preview
Annexure - II
JOB : Design, engineering ,supply installation, Testing & commissioning at Durgapur LPG plant.
packing & forwarding ,unloading of 10 KWp Grid tied solar power plant
Technical Specification
Design & Specification of the System:
The system should be designed by keeping the following points:
1. The plant will be installed in shade free areas so that maximum generation is attained
2. The system will be connected to the grid.
3. The power to be evacuated at 415V level
4. The plant will be installed facing south.
5. The BOM, layout drawings and the Electrical SLID will be submitted for necessary approval from both BPCL officials and consultant! TPIA before commencing of the work.
6. All outdoor junction boxes will have 1P65 rating and all indoor junction boxes will have 1P54 rating as per IEC 529
7. The performance ratio of the plant should be a minimum of 75% ,below which the difference will be adjusted in the security deposit.
8. Plant shall be designed to confirm with CEIG/CEA standards and any modification later on specified by the department will be in the scope of the contractor
9. All components installed shall confirm minimal technical requirements to MNRE standards as specified in their circular No. 30/11/2012-13/NSM http://mnre.gov.in/file-manager/UserFiles/Scheme-Grid-Connected-Rooftop-&-small-solar- power-pla nts.pdf
Page 1 of 19
10. The overall PV system should be designed according to following standards in addition to the
specific codes and standards specified for individual system components/equipment's -
• IEC/TS 62548 - Photovoltaic (PV) arrays - Design requirements • IEC 62738 - Design guidelines and recommendations for Photovoltaic power plants
• IEC 62093 - Balance-of-system components for photovoltaic systems - Design
qualification natural environments
• IEC 60364-7-712 - Requirements for special installations or locations - Solar
photovoltaic (PV) power supply systems
• IEC 62446-1 - Photovoltaic (PV) systems - Requirements for testing, documentation
and maintenance - Part 1: Grid connected systems - Documentation, commissioning
tests and inspection
• IEC 62446-2 - Maintenance of PV Systems
• IEC 61724 - Photovoltaic system performance monitoring - Guidelines for
measurement, data exchange and analysis
and Maintaining Photovoltaic (PV) • NECA 412-2012 - Standard for Installing Power Systems
On-site measurement of current-
IEC 61829 - Photovoltaic (PV) array - voltage characteristics
• IEEE 1547 - Standard for Interconnecting Distributed Resources with Electric Power
Systems
r.D%/ hAnr41110C.
The modules shall confirm to the following requirements:
1. The module should be certified by MNRE and to be made in India origin.
2. Capacity as per IEC testing condition should be greater than 300 Wp & It should be Polycrystalline
3. Efficiency of the module should be more than 15.5%
4. It should have tolerance of +3%. No negative tolerance will be permitted.
5. The module should have the following certifications:
a. IEC 61215— Design & quality
b. IEC 61730— Safety Class 1 & 2
c. IEC 61701 - Salt mist corrosion & severity
d. IEC 62804— PID resistance (PID) free
e. IEC 62716 - PV modules - Ammonia corrosion testing coastal locations
6. Back sheet to be made of PVF (Poly vinyl fluoride)
7. Module should have anti reflective coating.
8. The temperature co-efficient for power output of the Solar PV module shall not be more than -0.42% / °C.
9. All photovoltaic modules shall have linear performance warranty from second year. The solar PV modules offered shall not degrade more than 2.5% in first year and not more than 1% from second year of its rated power.
10. The module mismatch losses for modules connected to an inverter shall be less than 2%.
11. The SPV module shall be made up of impact resistant, low iron and high transmissivity toughened glass. The front surface shall give high encapsulation gain.
12. The SPV modules shall have suitable encapsulation and sealing arrangements to protect the silicon cells from environment. The .encapsulation arrangement shall ensure complete moisture proofing for theéptire life of solar modules.
Page2 of 19
13. The equipment shall be designed to give efficient and reliable performance and shall be such that the risks of accidental short-circuit due to animals, birds or vermin are obviated.
14. The data sheets of all modules shall be provided. The exact power of the module shall be indicated if the data sheet consists of a range of modules with varying output power.
15. It should perform satisfactorily in RH of 95% and between temperatures of -10 degrees to +60 deg.
16. RF ID tag - Modules deployed must use a RF identification tag. The following information must be mentioned in the RFID used on each module (This can be inside or outside the laminate, but must be able to withstand harsh environmental conditions).
a. Name of the manufacturer of the PV module;
b. Name of the manufacturer of solar cells;
c. Month and year of the manufacture (separate for solar cells and modules);
d. Country of origin (separately for solar cells and modules);
e. I-V curve for the module wattage, Im, Vm and FF for the module;
f. Unique serial number and model number of the modules;
g. Date and year of obtaining IEC PV module qualification certificate;
h. Other relevant information on traceability of solar cells and module as per ISO 9001 and ISO 14001.
17. All individual modules shall be provided with Name Plate label at the back of module which shall provide the information given below for identification. They shall be clearly visible and shall not be hidden by equipment wiring. Type of labels and fixing of labels shall be such that they are not likely to peel off/ fall off during the life of the panel.
a. Name of the Project, Owner's Name and Logo
b. Manufacturer's Name
c. Model Number, Serial Number
d. Overall Dimensions (WxLxD)
e. Weight (kg)
f. Maximum Power (max)' Voltage (Vmp) Current (Imp)
g. Short circuit current (Isc), Open Circuit Voltage (Voc) h. Main System Voltage I. Relevant standards, Certification lab. name
j. Warnings, if any
18. The module junction box will conform to 1P67 rating, will have 3 bypass diodes and will be made with Polycarbonate terminated with connectors adaptive to MC4 type connector directly. MC4 type connector should be certified by testing agencies like TUV cbmpetent for the purpose.
19. The typical solar PV module electrical characteristics including current-voltage (I-V) performance curves and temperature coefficients of power, voltage and current shall be provided for all the modules supplied. However, the tabulated document with all the relevant data like voltage, current, power output for each module is also required to be provided along with the supply.
20. Module frame - Anodized Aluminium Non - corrosive and electrolytically compatible with the mounting structure material. The anodizing thickness shall be 15 microns & above.
21. Termination box -Thermo -plastic, IP 65, UV resistant 22. Blocking diodes - Schottky type
23. Fill factor of the module shall not be less than 0.75.
24. The bird spike shall be provided to avoid bird sitting on the solar modules at the highest point of the array/module structure.
Page 3 of 19
25. Testing of Solar PV Modules
a. PV modules must qualify test from IEC/NABL accredited laboratory as per relevant
IEC standard and report/certification of the same must be attached. The
performance of PV modules at STC conditions must be tested and approved by one
of the IEC / NABL Accredited Testing Laboratories / Solar Energy Centre of MNRE/ any other MNRE authorized test laboratories/centers.
26. The PV strings and array shall be so designed that it matches the inverter/PCU input specifications.
PCU Invertor:
1. The capacity of the String invertor's should be 30 kw - 1 no & 20 kw - 1 no.
2. Maximum power point tracker shall be integrated in the PCU/Inverter to maximize energy drawn from the array. The MPPT charge controller should comply with IEC
62093 and IEC 60068-2. A conformance certificate for the same shall be submitted, either through datasheet of OEM or certification by the manufacturer.
3. Invertor efficiency to be greater than 98.5%
4. Overload capacity - 125% for 10mm
5. Should have transformer-less design
6. Invertor's should have anti islanding protection
7. Invertor should also be DG set interactive
8. It should have a LCD display to show all relevant parameters
9. The invertors shall have 1P65(outdoor) /1P21(indoor) and protection class II
10. The invertor shall have Earth leakage fault protection
11. Warranty of the PCU will be for 5 years
12. PCU/Inverter shall be capable of complete automatic operation including wake-up' synchronization and shut down;
13. The output of power factor of PCU inverter shall be suitable for all voltage ranges or sink of reactive power and the inverter should have internal protection arrangement against any sustainable fault in feeder line and against the lightening on feeder;
14. Built-in meter and data logger to monitor plant performance through external computer shall be provided;
15. The PCU/Inverters should be tested from the MNRE approved test centres/NABL/BIS/IEC accredited testing-calibration laboratories. In case of imported power conditioning units, they should by IEC approved by international test houses.
• Codes and Standards:
Shall comply to all the relevant standards, but not limited to the following:
Codes Description
IEC 61727 Photovoltaic (PV) systems - Characteristics of the utility interface
IEC 61683 Photovoltaic systems —Power Conditioners - Procedure for measuring
efficiency
IEC 62116 Utility-interconnected photovoltaic inverters -Test procedure of
islanding prevention measures
IEC 62109-1 & 2 Safety of power converters for use in photovoltaic power systems
EN 53030 Overall efficiency of grid connected photovoltaic inverters
IEC 62093 Balance-of-system components for photovoltaic systems - Design
qualification natural environments
IEEE 929-2000 Recommended Practice for Utility Interface of Photovoltaic (PV)
Systems
Lim Pae4of19
IEC 62894 Photovoltaic Inverters - Data Sheet and Name Plate
IEC 62910 Utility-interconnected photovoltaic inverters - Test procedure for low-
voltage ride through measurements
UL 1741 Standard for Inverters, converters, controllers and interconnection system equipment for use with distributed energy resources
IEEE 1547 Standard for interconnecting distributed resources with electric
power systems
IEEE 519 Recommended Practices and Requirements for Harmonic Control in
Electrical Power Systems
IEC 60068 Environmental Testing
IEC 62891 Indoor testing, characterization and evaluation of the overall efficiency of photovoltaic grid connected inverters
IEC 61000 Electromagnetic Compatibility
IS 3043/IEEE 80 Code of practice for earthing
BDEW 2008 Technical Guidelines for Generating plant connected to medium voltage network
• Conformance Certificate to the above mentioned standards shall be submitted through datasheets of OEM or certified by the OEM.
• The PCU/lnverter shall have efficiency in conformance with IEC 61683 and a conformance certificate shall be submitted, duly certified by the manufacturer.
• The inverter output shall always confirm to the captive load bus in terms of voltage and
frequency. The inverter shall be self-commutated with Pulse Width Modulation technology.
Technical details required are as under
Parameters Values
Output frequency 50 Hz +/- 0.5% Hz (Inverter to follow grid/captive load
bus frequency up to +/- 3 Hz of the nominal output frequency during normal operation)
Maximum Input voltage 1000 V DC
THD (Current) Less than 3 %
Power factor control range > = 0.9 lead or lag
Pae5of19
No load loss <1% of rated power and maximum loss in sleep mode
shall be less than 0.05%
Ambient temperature iOC to +60C
Humidity 95 % non-condensing
Enclosure( type) IP 54 (Indoor rated)
IP 65 (Outdoor rated)
Third party conformance certificate (from a certified
testing agency) is required to be submitted for IP degree
of protection.
Overload Capacity 125% for 10 min and 150% for 1 mm
120% at 25 degree C continuous on DC side
DC Injection Less than 0.5% of nominal load current
Electromagnetic Compatibility As per [C 61000
Noise level Less than 65 dB at 1 mt.
• PCU shall have Low Voltage Ride-Through (LVRT) feature to provide support during grid
fault! disturbance. Inverter shall continuously monitor the condition of the grid/input feeder bus, and in the event of grid/bus unavailability, the inverter shall automatically
switch to off-grid supply within 20-50 milliseconds. The solar system shall be
resynchronized with the grid/bus immediately after the restoration of grid.
Grid/Bus voltage shall also be continuously monitored and in the event of voltage going
below and above a preset value, the solar system shall be disconnected from the grid
within the set time. Both over voltage and under voltage relays shall have adjustable
voltage (50% to 130%) and time settings (0 to 5 seconds).
• The operating voltage range of PCU and the MPPT shall be large enough so that it
satisfactorily operates for PV modules exposed to the maximum ambient temperature U
of 60 C.
• DC lines shall have suitably rated isolators to allow safe start up and shut down of
the system.
The PCU must have the feature to work in tandem with other similar PCUs and to be successively switched "ON' and "OFF" automatically based on solar radiation variations during the day.
• Operating temperature range : (-)10°C to (+)60°C
• Remote as well as local monitoring shall be provided. Built-in data logger (to
record all the important operational parameters and all the events) to monitor
plant performance through external PC shall be provided. The communication
shall be in such a way that the PCU can be monitored with the help of
appropriate software from the centralized server. The PCU shall have the facility
to provide the analysis for reason of tripping, in
cases of inadvertent tripping.
• The surge rating of the inverter shall be up to 150% of the continuous rating for a minimum of 30 seconds.
• PCU shall include ground lugs for equipment and PV array groundings. The DC circuit ground shall be a solid single point ground connection.
•
Where PCU has not been provided with galvanic isolation, a type B residual
current device (RCD) according to IEC 60755 (Amendment-2) shall be installed to provide fault protection by automatic disconnection of supply. Inbuilt RCD will also be accepted.
.\
Paee 6 of 19
• PCU shall have the facility to export excess PV power to grid in case consumption of load is less than the generation and net/gross metering is permissible. The
provision should be there to enable and disable this export feature.
• PCU shall be tropicalized and design shall be compatible with conditions prevailing at site. Provision of exhaust fan with proper ducting for cooling of PCUs shall be
incorporated in the PCUs.
• Nuts, bolts and the PCU enclosure shall have to be adequately protected taking into consideration the atmosphere and weather prevailing in the area.
• Rubber mats shall also be provided in the PCU control room.
• Display:
PCU shall have the facility to display the basic parameters of the system on in-built LED/LCD display on its front panel or on separate data logging/display device to display following or through any other indication means:
1. DC Input Voltage
2. DC Input current
3. AC Output Voltage
4. AC Output Current
5. AC Power output (kW)
6. Frequency
7. Battery parameters (in case of hybrid systems with battery storage solution)
8. Time and date
9. Time active
10. Time disabled
11. Time idle 0
12. Temperatures ( C) : Ambient as well as internal 13. Converter status 14. AC over voltage
15. AC under voltage
16. Over frequency
17. Under frequency
18. Ground/Earth fault
19. Inverter ON/OFF
20. Grid/Feeder Bus ON/OFF
21. Inverter over-load
22. Inverter over-temperature
Protections: Following is an indicative list of protections (the actual scheme shall be finalized at design stage): 1. Over-voltage both at input and output
2. Over-current both at input and output
3. Over/under grid/bus frequency
4. Over temperature
5. Short circuit on AC side
6. Reverse polarity protection
7. Array ground fault protection
8. Protection against earth leakage faults
Page 7 of 19
9. Protection against lightning induced surges
10. Protection against surge voltage induced at input and output due to external source
11. Capacity to feed in reactive power faults
12. Provision for input & output isolation.
13. PCU shall have arrangement for adjusting DC input current and should trip against sustainable fault downstream and shall not start till the fault is rectified.
In addition, PCU shall ensure following protection measures:
1. The PCU shall include appropriate self- protective and self- diagnostic feature to protect
itself and the PV array from damage in the event of PCU component failure or from
parameters beyond the PCU5 safe operating range due to internal or external causes.
The self-protective features shall not allow signals from the PCU diagnostic circuit to
cause the PCU to be operated in a manner which may be unsafe or damaging. Faults due
to malfunctioning within the PCU, including commutation failure, shall be cleared by the
PCU protective devices.
2. The PCU shall have internal protection arrangement against any sustained fault in the feeder line and against lightning in the feeder line.
3. Automatic reset of all non-critical faults such as overloads, AC over voltage/under voltage, etc. once the fault has been cleared.
• Operating modes of PCU:
1. LOW VOLTAGE MODE: The control system shall continuously monitor the output of
the solar PV plant. Once the pre-set value is exceeded, PCU shall automatically "wake
up" and begin to export power provided there is sufficient solar energy and the PCU
voltage and frequency are in the specified range.
2. ACTIVE Maximum Power Point Tracking (MPPT) MODE (HIGH POWER MODE): When
solar radiation increases further, the PCU shall enter Maximum Power Point Tracking
(MPPT) mode and adjust the voltage of the SPV array to maximize solar energy fed
into the grid. When the solar radiation falls below threshold level, the PCU shall enter
in low power mode.
3. SLEEP MODE: Automatic 'sleep' mode shall be provided so that unnecessary losses are
minimized at night. The threshold DC voltage level/power level of the PCU at which it
shall enter into the sleep mode and back to low power mode and MPPT mode shall be
duly certified by Chartered Electrical Engineer.
• DC side of each inverter shall be earthed to distinct earth pit through adequate size
conductor as per IS 3043. The size of conductor shall be as per the maximum fault
current on DC side.
INTEGRATION OF PV POWER WITH GRID:
1. The output power from SPV would be fed to the inverters which converts DC produced by SPV array to AC and feeds it into the main electricity grid after synchronization.
2. The AC output of the solar grid inverter shall be connected to the buildings electrical
system after the WEST BENGAL ELECTRCITY BOARD service connection meter and
main switch on the load side.
3. The solar grid inverter output shall be connected to a dedicated module in the main MDB of the building and not be connected to a nearby load or socket.
Pane 8 of 19
4. The wiring of the solar grid invertor cannot run parallel to the diesel generator. The solar grid invertor must be connected to a distribution board on the grid side of the automatic or manual change over switch.
5. In case of grid failure or low or high voltage solar PV system shall be out of synchronization and shall be disconnected from the grid. Once the DG set comes into service PV system shall again be synchronized with DG supply and load requirement would be met to the extent of availability of power.
6. 4 pole isolation of inverter output with respect to the grid/DG power connection need to be provided.
7. The design should be such that the invertor can synchronize with 2 DG sets of different capacities. Any 1 DG set will be operated at a time.
Microorocessor based Data Logger System
1. The system shall comply with the conditions specified in IEC 61724: Photovoltaic System Performance Monitoring - Guidelines for measurement, data exchange and analysis.
2. The performance and generation data shall be recorded using a data logger or the SCADA system. The Monitoring System shall comprise of the following main components:
• PCU shall log the inverter performance data and transmit the same to the Data logger.
Data logger gathers information and monitors the performance of the inverter.
• Data logger supports measurements from the external sensors. The data can be
acquired remotely via a modem.
• Remote monitoring equipment to measure following weather related parameters:
o Solar radiation (in plane of array) o Module temperature
o Ambient Temperature o Wind Speed
• Test certificate for these instruments conforming their efficiency shall be submitted.
• PC Data logging software shall enable automatic long-term storage of measured data from PV- Plant.
• Communication interface - The entire system shall be capable enough to be operated and monitored via several interfaces (RS232/RS485, LAN Website/ Telephone modem) in addition to the information indicated on the operator panel. Further information can
also be acquired remotely through the interfaces mentioned above.
• The software interfaces for LAN and LAN cables etc. for commissioning of complete
data logging /monitoring system shall also be supplied. 3. The key values to be made available at the data logger -
• PV array energy production through digital energy meters (Power, Voltage and
Current)
• Battery parameters through Ah meters (Voltage and Current at Battery terminals), in
case of hybrid system with battery storage
• Solar Irradiance through pyranometers
• Temperature - PV module and ambient
• Wind Speed through anemometer
Pae9of19
4. The data logger shall be able to provide following reports -
. Data Log Report on a daily, monthly and annual basis
• Event Log and Trip Analysis Report
• Sequence of Event Report • Plant Performance - uptime and efficiency
5. A graphical daily and monthly generation report as well as generation w.r.t. radiation
shall be made available through network (local or remote) which can be accessed from
anywhere.
6. A complete and comprehensive "Remote Monitoring System monitoring solution" report
shall be made available to-
i) know what is produced in real time
ii) have detailed analytics to understand if the power generated is 'as expected/designed', and
iii) know any issues with field equipment and correct, through effective O&M.
7. The UPS based AC Power supply of suitable rating to cater all the load requirements of
Microprocessor based Data Logger system and its auxiliaries shall be provided. The
power backup for the entire system should be at least for 02 hours.
Module Mounting structures:
1. Mounting structures to be designed after taking necessary measurements in the site.
2. The modules should be mounted at the necessary fixed tilt of 13 degrees
3. In case of Flat roof the minimum clearance between ground level and lowest part of
structure will be 300mm and In case of slant roofs, special rail-based beam/channel
structures may be adopted to mount the modules with a minimum gap of 100 mm
between modules and roof.
4. The structure should be made of Galvanized iron and should be coated with minimum of 80 microns or higher as per IS 4759 for flat roof. For slant roof it should be Aluminium.
5. Fastners should be stainless steel and of SS 304 grade
6. The structure has to with stand a wind velocity of 150kms/hr. A detailed design calculation report, properly certified by Chartered Structural engineer, evaluating the
Paee 10 of 19
strength of rooftop structures and PV modules to sustain the maximum wind speed shall be submitted.
7. The necessary civil work will be done for the installation with PCC 1:2:4, M15 grade. Designing of civil foundation shall be done / certified by a govt approved valuer
8. The height of the foundation and the structure to be decided based on the site in order to avoid shading in some areas.
9. The structure will be designed based on the load bearing capacity of the roof. The total load of the structure on the roof should be less than SOkg/sqms
10. The PV array must be designed suitably with safe walk way for routine maintenance d
11. Module mounting structures will be inspected and cleared by client! Consultant/3 party agency
12. The structure shall support Solar PV modules in portrait orientation, absorb and transfer the mechanical loads to the ground/roof properly. Welding or complex fixing mechanism shall not be allowed for installation of module mounting structure to the foundation.
13. All mechanical items must be supplied as per approved drawing, BOQ and directions of EIC.
14. DG room - Mounting structures suitable for Sheet metal roof with Trapezoidal profile to be used for the DG room. The clamps and the purlins have to be in Aluminium.The DG room installation has to be leak proof.The slope of the installation in the DG room can be the same as the roof itself
15. The orientation can be decided based on the sheet metal roof.
16. In case of rooftop systems with unavailability of proper south facing roof, suitable design proposal shall be submitted, highlighting the guaranteed solar power generation in that orientation.
17. Proper design and calculations report, properly certified by Chartered Electrical/Structural engineers shall be submitted to EIC prior to commencement of work at site.
18. In case of rooftop systems, a detailed design calculation report evaluating the strength of existing rooftop to sustain the dead weight of the system (Structure and Module) as well as the dynamic weight of the installed system shall also be submitted. The report should qualify the rooftop for installation of the Solar PV System with desired design parameters and having sufficient safety margin. In case the rooftop is not having enough strength to support the PV System installation, strengthening of the same shall also be carried out. The work shall commence only after submission of load bearing strength calculation duly certified by Chartered Engineer.
Codes Description
UL 2703 Standard for Mounting Systems, Mounting Devices,
Clamping/Retention Devices, and Ground Lugs for Use with Flat-Plate
Photovoltaic Modules and Panels
IS 4759 Hot-dip zinc coatings on structural steel and other allied products
IS 2629 Recommended practice for hot-dip galvanizing of iron and steel
NECA 412-2012 Standard for installing and maintaining Photovoltaic power systems
IS 3043/IEEE 80 Code of practice for earthing
Page 11 of 19
IS 875 Code of Practice for Design Loads (Other Than Earthquake) For
Buildings And Structure. Part 1: Dead Loads - Unit Weights of Building
Material And Stored Materials, Part 2: Imposed Loads, Part 3: Wind
Loads, Part 5: Special Loads And Combinations
PROTECTIONS:
The system should be provided with all necessary protections like earthing, lightning and grid islanding as follows:
Lightning and Over Voltage protection
1. The SPV Power Plant should be provided with lightning & over voltage protection. The main aim in this protection shall be to reduce the over voltage to a tolerable value before it reaches the PV or other sub system components. Metal Oxide Varistors (MOVs) shall be provided inside the Array Junction Boxes/String Monitoring Boxes, if applicable.
In addition, suitable MOVs to be provided in the lnverter/PCU as well.
2. The source of over voltage can be lightning or other atmospheric disturbance. Lightning
Protection System (LPS) i.e. lightning conductors or mesh shall be provided so as to
prevent direct lightning strike into the PV modules. It is to be ensured that adequate
separation distance is kept between the LPS and PV modules. Main aim of over voltage protection is to reduce the overvoltage to a tolerable level before it reaches the PV or
other sub-system components. Lightning protection should be provided in accordance
with IEC 62305. Relevant documents to conform the same shall be submitted.
3. The Lighting Arrestor (LA) has to be designed as per applicable standards so that whole of the Solar PV Plant is protected. Design calculations for Lightning Protection, System duly certified by Chartered Engineer shall be submitted.
4. Necessary concrete foundation or any other arrangement for holding the lightning conductor in position is to be made after giving due consideration to shadow on PV array, maximum wind speed and maintenance requirement at site in future.
5. The lightning conductor and structures shall be earthed through flats as per applicable standards with earth pits. Each lightning conductor shall be fitted with individual earth
pit as per required standards including accessories, and providing masonry enclosure. Else, a matrix of lightning conductors is to be created which will be required to be
connected to an earth.
Surge Protection:
Internal surge protection shall consist of three MOV type surge-arrestors connected from +ve and-ye terminals to earth (via V arrangement)/SPDs
Earthing
The photovoltaic modules, mounting structure, Balance of system (BOS) and other components of power plant require proper grounding for protection against any serious faults as guided by IS 3043 and IEEE 80.
2. If previous soil resistivity measurement of the site is not available, a fresh measurement needs to be undertaken prior to deciding on earthing solutions required.
3. Requisite earthing for inverters, junction box, SMU etc. as per standard procedure shall be ensured.
Pane 12 of 19
4. All metal casing/shielding of the plant shall be thoroughly grounded in accordance with Indian Electricity Act/IE Rules.
S. An adequate number and appropriate size of IS 3043 compliant earthing pits shall be constructed, as approved by Chartered Electrical Engineer.
6. Each Lightening Arrester shall have to be earthed through suitable size earth bus with individual earth pits.
7. Earthing system design should be as per the standard practices i.e. IS standard (IS: 3043). Design calculations, duly certified by Chartered Electrical Engineer shall be submitted.
8. Overall earth resistance shall not be more than 1 ohm.
Grid Islandin:
1. In the event of a power failure on the electric grid, it is required that any independent power-producing inverters attached to the grid turn off in a short period of time. This prevents the DC-to-AC inverters from continuing to feed power into small sections of the grid, known as "Islands". Powered islands present a risk to workers who may expect the area to be unpowered, and they may also damage grid-tied equipment. The Rooftop PV system shall be equipped with islanding protection. In addition to disconnection from the grid (due to islanding protection) disconnection due to under and over voltage conditions shall also be provided;
2. A manual disconnect 4 pole isolation switch beside automatic disconnection to grid would have to be provided at utility end to isolate the grid connection by the utility personnel to carry out any maintenance. This switch shall be locked by the utility personnel.
Cables and Accessories
1. All the cables required to be installed shall be copper armored or equivalent laid properly either through cable tray or conduit as per the site requirement. These cables should conform to relevant IS standard (IS 1554 / 694 Part 1 of 1988) and shall be of 650 V/1.1 kV grade as per requirement, heavy duty, fire/flame retardant low smoke (FRLS) extruded PVC type ST-1 outer sheathed. All the installation accessories such as glands, cable ties, lugs, fasteners and various sundry materials etc. shall be ensured.
2. All the cables shall be insulated with PVC (type-A) for working voltages up to and including 1100 V and must be UV resistant for outdoor installation.
3. Cabling on DC side of the system shall be as short as possible to minimize the vltage drop in the wiring. Voltage drop on the DC side from array to the inverter should not be more than 2%. Cable sizing calculation, duly certified by Chartered Engineer, shall be submitted.
4. For the AC cabling, armoured PVC insulated cables shall be used. The sizing of cable shall be based on the maximum load flow considering the voltage drop within the permissible limit of 3%. The sizing calculation of the AC cable duly certified by Chartered Electrical Engineer shall be submitted. All the cables shall be laid through trench or tray. If required, preparation of trench or tray shall be ensured. Cables shall have proper end termination, glanding and lugging.
5. Overvoltage protection is to be provided. Design Overvoltage capacity of 125% of continuous rating for 10 sec has to be ensured. The principle aim for this protection is to reduce the over voltage to a tolerable value before it reaches the PV or other subsystem components. The source of over voltage can be lightning or any other atmospheric disturbance or internal system disturbance
Page 13 of 19
6. Overvoltage protection is to be provided. Design Overvoltage capacity of 125% of continuous rating for 10 sec has to be ensured. The principle aim for this protection is to reduce the over voltage to a tolerable value before it reaches the PV or other subsystem components. The source of over voltage can be lightning or any other atmospheric disturbance or internal system disturbance
7. Cables are to be routed neatly in standard manner through GI perforated cable trays & cable marker to be placed for future identification. For array wiring, suitable cable tray or metal conduit with proper support shall be provided and fastened on the roof and wall as per instruction of BPCL.
8. Cable trays shall have standard width of 150 mm, 300 mm & 600 mm and standard lengths of 2.5 meter. Thickness of mild steel sheets used for fabrication of cable trays and fittings shall be minimum 2 mm. The thickness of side coupler plates shall be minimum 3 mm.
9. For protection of unarmored cables suitable conduits are to be provided.
10. The switches/circuit breakers/connectors required shall conform to IEC 60947 (Part-I, II &
Ill) or IS 60947 (Part-I, II & III) EN 50521. Relevant conformance certificates shall be submitted by the successful bidder.
CONNECTIVITY:
The connectivity for power evacuation shall be strictly as per the Guidelines of WEST BENGAL ELECTRICITY BOARD. The power shall be evacuated at 415V - 3 phase.
JUNCTION BOXES(JBs):
1. The junction boxes are to be provided in the PV array for termination of connecting cables. The iBs shall be made of GRP/FRP/Powder coated aluminum/cast aluminui alloy with full dust, water and vermin proof arrangement. All wires/cables must be terminated through cable lugs. The iBs shall be such that input and output termination can be made through suitable cable glands
2. Copper bus bars/terminal blocks housed in the junction box with suitable termination threads conforming to 1P65 standard and IEC 62208 hinged door with EPDM rubber gasket to prevent water entry. Single compression cable glands and earthing shall be provided
3. Each JB shall have high quality suitable capacity metal oxide varistors (MOV5)/surge arrestors, suitable reverse blocking diodes. The JB5 shall have suitable arrangement for monitoring and disconnection of each of the groups.
4. Suitable markings shall be provided on the bus bar for easy identification and the cable ferrules must be fitted at the cable termination points for identification.
DC DISTRIBUTION BOARD:
1. DC distribution panel to receive the DC output from the array field
2. DC DPBs shall have sheet enclosure to protect against dust and vermin proof conforming to IP 65. The bus bars shall be made of copper of desired size. Suitable capacity MCBs/MCCB shall be provided for controlling the DC power output to the PCU along with necessary surge arrestors.
AC Distribution Box (ACDB)/LT Switchgear Panel with Metering
LT Switchgear Panel with metering provision has to be provided if the existing switchgear panel does not have sufficient provision for additional incomer source and outgoing feeder.
LT Switchgear Panel shall be mounted in existing AC LT panel room, if possible. Else, a separate housing faciijty shall have to be built.
Page 14 of 19
3-phase, 50 Hz, LT switchgear system shall consist of LT Switchgear boards/panels in between PCU and transformer (if required as per the system configuration or lnverter/PCU
OEM) as per the requirement. The scope shall include standard load distribution boards/panels complete with cubicles, protection, metering, bus-bar system, cabling, wiring and other accessories, the quantities/ratings of which shall be finalized during detail
engineering.
LT Panel is intended to supply the solar power generated to the captive load, either directly (in case of captive load bus voltage matching the inverter/PCU output voltage) or through stepping-up the voltage level as per the system configuration. The LT Switchgear shall be connected to Transformer, if required as per the system configuration or lnverter/PCU OEM.
All the above boards/panels shall be metal enclosed, 415V switchgear type, complete with suitably rated: a) Draw out type Air Circuit Breaker b) Surge Protection Devices
c) Required no. of MCCBs
d) Numerical Relays, with the provision of in-built event logger
e) Required no. of Multifunction meters
f) Required no. of Energy meters
g) Bus bars
h) Local control switches
I) Indicators (LED type) as per requirement
j) All necessary auxiliaries for control and supervisory circuits, and other relays as required
k) Other additional feeder units necessar to fulfill the requirements of the specification and sockets etc.
I) All secondary wiring, terminal blocks, labeling and nameplates, sockets etc
m) Cubicle lighting including lighting fixtures and power and communication sockets
n) Space Heaters
o) Coordination and provision of necessary contacts and/or ports for integration with plant SCADA/Remote Monitoring system
p) Any other item(s) not mentioned specifically but necessary for the satisfactory completion of system will be in scope of supply.
Technical Requirements:
Location Indoor
No. of bus bars, 3-phase 1
Rated voltage , V As per the system configuration requirement
Rated frequency Hz 50 ± 0.5 Hz
Rated circuit breaker short circuit
breaking capacity 50 KA
Protection Class Min. IP 54 or higher as per requirement of location
Control voltage, DC Uninterrupted supply through power pack/UPS
with voltage level as per system requirement
Auxiliary AC supply, 3 phase 415 ± 10 %
Material of Bus bar Aluminum alloy / copper
Type of Earthing Solidly earthed
Codes and Standards Shall comply to all the relevant standards, but not limited to the following:
Codes Description ... IS/IEC 60529 Degrees of protection provided by enclosures (IP Code)
IEC 60439 / IS 8623 Low-voltage switchgear and control gear assemblies IEC 60364 Low-voltage electrical installations
IS/IEC 60947 Low-voltage switchgear and control gear
IS 3072 Code of practice for installation and maintenance of Switchgear
IS 3231 Electrical relays for power system protection
IS 13703 / IEC 60269 Low voltage fuses for voltage not exceeding 1000 V AC or 1500 V DC - specification
IEC 61643 Low-voltage surge protective devices
IS 3043/IEEE 80 Code of practice for earthing IS 14697 AC Static Transformer Operated Watt-hour and VAr-hour
Meters - Class 0.2 5 and 0.5 5 - Specification
IS 13010 AC Watt-hour Meters - Class 0.5, 1 and 2 - Specification
IS 10118 Code of practice for selection, installation and maintenance of switchgear and control gear.
• Standard construction philosophy shall be adopted in construction of switchgear panels, complying with national and international standards as well as Indian Electricity Grid Code and CEA/CERC guidelines.
• Compartmentalization philosophy shall be adopted while constructing and segregating different components of switchgear panel, based on their functional/operational requirements.
• The ACDB shall be fabricated out of minimum 16 SWG MS sheet and painted with anti-corrosive primer and two coats of grey enamel paint as per specifications.
• Power bus-bars and insulators shall comply with specifications as given in standards/codes, ensuring adequate operational and safety features. Calculations establishing the adequacy of bus bar sizes for specified current ratings duly certified by Chartered Engineer shall be submitted.
• Adequate protection measures shall be ensured through means of Circuit B.reakers, MCCBs, Contactors, Surge Protection Devices and Fuses. The design selection of such components shall be ensured as per the system requirement and adequate design calculations/basis duly certified by Chartered Engineer shall be submitted. All the necessary test certificates shall be submitted to establish the compliance of these protection equipment(s)/components to the operational requirements outlined in the respective codes and standards.
• It shall be ensured that the equipment offered will carry the required load current at site ambient conditions specified and perform the operating duties without exceeding the permissible temperature as per standards and codes. Continuous current rating at 50°C ambient in no case shall be less than 90% of the normal rating specified. The de-rating factors, if any employed for each component and the basis for arriving at these de-rating factors shall be clearly specified, duly considering the specified current ratings and ambient temperature of 500C. Internal wiring shall be ensured through proper sizing wire, the design current carrying capacity of which shall be duly certified by Chartered Engineer. All the internal wiring shall be
/1
-.-t (••' .
Page 16 of 19
• Internal wiring shall be ensured through proper sizing wire, the design current carrying capacity of which shall be duly certified by Chartered Engineer. All the internal wiring shall be
done through properly chosen color coded wires and neatly dressed for easy identification.
• The protection coordination and interlocks shall be ensured. The schematics for the same duly certified by Chartered Engineer shall be submitted before final configuration.
• Following drawings and manuals shall be submitted in three copies.
a) General arrangement of panel showing overall dimensions with foundation plan, terminal location, total weight, sectional views, operating mechanism, and Bill of materials
b) Schematic and wiring diagram for control logic/circuitary
c) Closing and Opening timing charts of main and auxiliary contacts
d) Manufacturing schedule and test schedule
e) Instruction manual along O&M manual and individual components' catalogue
• There should be provision in the system for measurement and display of Solar Power being fed to the load through each inverter in case of multiple inverters. System should also have the capability to display the minimum, maximum and average solar power being fed to the
system on daily/monthly/yearly basis.
• The system should also be capable to measure, register and display the solar energy consumption on daily/monthly/yearly basis. The energy meter must show the exact line
current, voltage, instantaneous power and energy reading (daily & cumulative).
• The metering facility of the system shall comply following minimum specifications:
o Solar system metering should work accurately for the complete range of energy, voltage, current, frequency and power factor envisaged for this installation. Cumulative
KWH will be indicated continuously bydefault & other parameters through push-button flashing LED visible from the front.
o Applicable standards for energy meters (as per the accuracy class requirement): 'I
IS 14697— For Class 0.2 and 0.5
IS 13010— For Class 0.5, 1 and 2
o Accuracy Class Index of energy meter: 0.5 or better.
o Memory: Non volatile memory independent of battery backup, memory should be retained up to 10 year in case of power failure.
o Software and Communication Compatibility: Shall be compatible to communicate and transfer all types of instantaneous and cumulative energy metering data with the Microprocessor based Data Logger System. All types of necessary software and hardware to connect the meter with Microprocessor based Data Logger System shall also be supplied.
o Climatic Condition: The meter should function satisfactorily in India with high end temperature as 602C and humidity up to 95%.
TOOLS & TACKLES AND SPARES:
After completion of installation and commissioning of the power plant, necessary tools and tackles are to be provided free of cost by the tenderer for maintenance purpose. List of such
Page 17 of 19
tools and tackles to be supplied by the tenderer to be submitted for approval of specifications and make from BPCL
A list of requisite spares in case of PCU/lnverter comprising of a set of control logic cards,
IGBT driver cards, Junction boxes, fuses, MOV5/arrestors, MCCBs etc along with spare set of
PV modules shall be indicated. A minimum set of spares shall be maintained in the plant
itself for the entire period of warranty and comprehensive maintenance, which upon its use
shall be replenished.
DANGER BOARDS AND SIGNAGES:
Caution & Danger boards should be provided as and where necessary as per IE Act/IE Rules
as amended up to date. Three signages shall be provided one each at lnvertor, control room,
solar array area and main entry.
FIRE EXTINGUISHERS:
The firefighting system for the proposed power plant for fire protection shall consist of:
- Portable fire extinguishers in the control room for fire caused by electrical short circuits —Dry Chemical powder 9 kg 1 Nos & CO2 4.5kg 2 No
- Sand buckets in the control room - 101itres —4 nos
The installation of fire extinguishers should conform to TAC regulations and BIS standards.
The fire extinguishers shall be provided in the control room housing PCUs as well as on the
roof or site where the PV arrays have been installed.
DRAWINGS AND MANUALS:
• Two sets of engineering, electrical drawings and installation and O&M manuals shall be
maintained. Tenderers shall provide complete technical data sheets for each equipment giving details of the specifications along with make/makes in their tender along with the
basic design of the power plant and power evacuation, synchronization along with
protection equipment
• Approved lSl and reputed makes for equipment shall be used
DRAWINGS TO BE PREPARED/MAINTAINED BY CONTRACTOR AFTER AWARD OF CONTRACT:
The CONTRACTOR shall maintain the following drawings before award /intent and obtain
approval:
• General arrangement and dimensioned layout
• Schematic drawing showing the requirement of PV panel, power conditioning
units/Inverter, Junction boxes, AC and DC distribution boards, meters etc.
• Structural drawings along with foundation details for the structure
• Itemized bill of material for complete SV plant covering all the components and
associated accessories
• Layout of solar power array
SAFETY MEASURES:
• The Tenderer shall take entire responsibility for the electrical safety of the installation(s)
including connectivity with the grid and follow all the safety rules and regulations applicable as per Electricity Act 2003 and CEA guidelines etc.
Paee 18 of 19
• The CONTRACTOR shall display a board at the project site mentioning the Plant name; Capacity and Location.
• All necessary safety measures to be incorporated in designing the system. • Lightning protection to be provided separately as per the enclosed specification.
• Proper earthing to be provided to the unit and shall be connected to a separate Earth Pit provided for this structure.
• Necessary surge protection devices & MCB's to be provided on both DC and AC side as per the specification given
• The Array Junction boxes and all terminals to be connected with proper Lugs and terminals only
COMPREHENSIVE ANNUAL MAINTENANCE CONTRACT (AMC):
The plant shall be maintained for a period of 1 years (2+1) including the warranty period
of 2 years and one years Comprehensive AMC.
A minimum 4 visits or more if required per year to clean the modules for better performance to be maintained at site and also check the overall condition of the plant.
The contractor to ensure that the required optimum generation is maintained in the plant and plan more visits if required.
Training:
Necessary training to be provided by the contractor to the BPCL staff to Operate & maintain the plant at all times. Training on safety & emergency situations to be provided. Necessary manuals to be provided for reference.
Site visit:
The site can be visited at any point of time before the bidding process and the necessary inputs can be taken.
Completion period:
The completion period of the project shall be within 60days from the LOI date.
Paee 19 of 19
