NEPQA and solar testing in the RETS

1. NEPQA AND SOLAR TESTING IN RETS By Sujita Thakali
MSR/071/516

2. CONTENTS
Introduction
Block Diagram
Description of Components
Testing of solar panel
Photo
Conclusion

3. INTRODUCTION
NEPQA is the Nepal Photovoltaic Quality Assurance which is the
technical standard for the components of a Solar Photovoltaic(PV)
system.
The standard doesn’t remain constant it changes.
Based on this documents the RETS will test and certify the quality
of the PV systems and components in PV applications.
The RETS is authorized to carry out the quality test of the solar
photovoltaic system and its components and issue the certificate
using the Sampling Plan and Test Procedures of RETS.

4. BLOCK DIAGRAM
Charge
Controller
Battery
Solar panel
AC
appliances
Mobile
USB
Connection
Sun
Load Center
Inverter
DC lamps
Flow of
current

5. DESCRIPTION OF COMPONENTS
Solar Panel
Charge Controller
Battery
Inverter
DC LED Lamp

6. SOLAR PANEL
1. Different Capacity of Solar Panel are available which consists of Diode
for preventing from the reverse flow of electricity from the Battery
during night.
2. According to the Nepal Photovoltaic Quality Assurance(NEPQA) solar
panel should be of at least 17 volts at maximum power designed for
the 12 volt system voltage so that solar panel can charged the Battery
system.
3. Generally for the design of the small solar home pv system it consists
of 36 cells. Each cell has the voltage of 0.6 volt what ever dimension it
has been cut and power of the panel can be increased by increasing
the area.

7. BATTERY
• There are different types of Battery available in the market some
are compliance and some are not.
•The capacity of the battery is determined by the Ampere hour
rather than its voltage and label with C10, C20, C30, etc.
•The operation life cycle of the Li-Ion/Ni-MH battery must be at
least 3000 cycles at 20% DOD and 15000 cycles at 80% DOD.
•According to the NEPQA, for the battery with capacities greater
than 10Ah, deviation of battery capacity from its rated value must
not exceed -5% to 20% within 10 cycles of the test. And for the
battery with the capacity less or equal to 10Ah, the deviation of
battery capacity from its rated value stated by the manufacture
must not exceed the limit of -5% to +20% within 5 cycles of test.
This clause applies for all type of batteries.

8. CHARGE CONTROLLER
1. The function of Charge Controller is to prevent from the deep
discharge with any options for manual deactivation that is adaptable to
the battery type used, applicable to advanced type like microcontroller
based Charge controller and also prevent from over charging of battery.
2. Low Voltage Disconnection(LVD) and Low Voltage Reconnection(LVR)
3. Both have the setting point within ±2% at 25°C
4. i.e. for the battery of 12V LVD should be not less than 11.4V and LVR
should be not less than 12.5V

9. 3. High Voltage Disconnection(HVD) and High Voltage
Reconnection(HVR)
4. High Voltage Disconnection must be within the range of
(14-15)V for the 12V system and its also depends on the type of
battery used.

10. CC CONTINUE…..
7. The charge controller must withstand the rated current from
the PV module to battery and from battery to load at an
ambient temperature range of -5ºC to 40ºC.
8. There are mainly three terminals in Charge Controller. One
terminal is for Panel Connection, one for the battery connection
and another one is for Load connection.
9. For the Small Home Solar PV design the charge controller that
has USB port and lightening terminal are the main parts of the
charge controller.
10. The charge controller must function in accordance with the
pulse width modulation or the maximum power point tracking
principles

11. INVERTER
The inverter must have the rated AC output voltage of 220V ±5%
at the battery operating voltage from DC 90% to 120% and
maximum load current from 10% to 110% of the rated value.
 Output frequency of the inverter is 50hz ±2%.
Inverter Efficiency when operating with resistive loads at full
load must be at least 85%.
The quiescent current drawn by the inverter must not exceed
2% of the rated current of the inverter.
The inverter shouldn’t produce the noise more than 60db at 2m.

12. INVERTER CIRCUIT PROTECTION
Low battery shut down must be at battery voltage not less than
10.5 V for tubular plate battery in case of 12 V system. For 24 V or
48 V systems low battery shut down voltage must be 10.5N where
N is the no of Batteries in series connection.
Short circuit protection of the output terminals.
Reverse polarity protection on DC input terminals.
Appropriate indicators main charging , inverter ON, short circuit
and overload
The inverter should be have cooling systemor appropriate heat
sink

13. Inverter must be capable of operating safely for at least one
minute at 125% of rated power and at least 5 seconds at 150% of
rated power.
The minimum information must be included in the label of
inverter are
a. Manufacturer’s name and model
b. Rated Power in Watt or VA
C. Input and Output voltage in Volt and Frequency in Hz
d. Charging current, Load current, power factor, efficiency
e. Inverter Type

14. SOLAR PUMP
The pump can be centrifugal, positive displacement, progressive
cavity, submersible or surface type meeting the safety standards
of EN 809 and complies with IEC 60034-1
Pump motor efficiency must be at least 60%.
The pump must have thermal protection against overload,
reverse polarity and temperature
The pump must use standard submersible cable for submersible
pump.
The pump or pump set must have provision of stopping
operation under dry running or insufficient energy supply.

15. The pump must have protection against sand and silt.
Indelible label must be fixed on the pump, containing the details
1. Name of the manufacturers or distinctive logo
2. Model name and serial number
 The motor and pump must be warranted for at least 2 years.
The pump must be manufactured with non corrosive materials.
Ceramic or equivalent non corrodible materials must be used for
bearings. Rotors and impellers must be made of stainless steel
with minimum grade of AISI 304 or higher.
Oil must not be used for lubrication.

16. LAMP

17. • DC Led Lamp are prefer in the PV System. The viewing angle of
individual WLED must be equal to or greater than 100 degree.
•The luminous efficiency of individual WLED must be at least 100
Lumen/Watt.
•The lamp driver circuit efficiency must be at least 80%
•The Color Rendering Index (CRI) of the individual WLED must not
be less than 60 and the color temperature must be in the range of
5000K and 6000K
•In the lamp of multiple WLEDs, the WLEDs used must not differ
by more than 10% in individual WLED parameters (forward
voltage and color temperature) at specified current.
•The rated power of Lamp must be at least 1 watt and acceptable
tolerance for all to be +/-10%.

18. TESTING OF SOLAR PANEL
Even though there are 17+ Tests in CEC JRC ESTI Specification 503
In RETS there are two types of Tests in RETS
1.PIT(Product Introduction Test)
2. Random Sampling Test(RST)
PIT is done by observing the PV module and gathering the
indelible informations label where as RST in done by taking a large
number of sample from the population and proceed on testing.
It consists of the log book where the required information can be
logged in.

19. LOG BOOK

20. After filling the information in the log book then it is proceed
further in Laboratory called Quick Sun Solar Simulator Setup
which consist of three rooms where one room consists of source
of light- Xenon Lamp, flash generator where as in second room
there are temperature sensor, Monitor cell, Electronic unit and
another room where there is operator who control the system
through software

21. It is a setup in a dark room where each part of the wall is black
painted so that there is no any reflection.
Temperature Sensor is connected with the electronic unit to
sense the temperature of the simulation setup.
Monitor Cell is a unit cell which acts as a reference cell that
compares the irradiance and the uniformity with the test PV
module and calibration takes place simultaneously as the light
flash from the Xenon Lamp.
Electronic Unit acts as bridge between the PV module, Monitor
Cell, Temperature sensor, Flash Generator and PC. It is main part
of this setup because it controls the every components.

22. PROCEDURE
Initially the panel is given a code and is hanged at the wall of the
Simulator setup.
Then after connecting the probe from electronic unit to the
panel the room is closed.
The operator open the software and from the log book the
informations are filled by clicking on the Product database and
then since all the setup is ready then Measure button is clicked
on.
When the Measure button is clicked the flash is stroke at the
panel from the Lamp. Then the software automatically provide
the output whether it is pass or fail.

26. PHOTOS

27. CONCLUSION
In this way according to the NEPQA standard of Panel,
charge controller, battery inverter and lamps are
known and have overview on Solar Panel Testing.

28. REFERENCES
www.retsnepal.org.np
Credited to
www.ioe.edu.np(CES- Department)
Dr. Er. Ajay Kumar Jha(I.O.E pulchowk)
Er. Rabindra Lamichane (RETS)
Er. Madan Oli (RETS)
Er. Rudra Mani Pokharel(Ex. Technical Manager)

29. Thank you
(any querries are
welcome)