Due to the rapid increase in demand for electricity, the solar dc grid system is essential for fulfilling the supply of electricity of the country. But in the DC grid system, there needs certain protection in transmission and distribution line from different kinds of significant electrical faults. That is why this project tried to figure out a proper solution to that problem. That is the simultaneous monitoring and control of solid state relay. This project is called smart system because if any overcurrent or overloading fault arises and if any unexpected interruption happens in the line of DC grid, then surely the certain connected load will trip and the data will send to a remote distance to proper monitoring and control it.

4. Survey Analysis
Challenges
Proposed Solution
Design of Solid State Relay
Server
Project Flow Chart
Results and Outcomes
Applications
Future Work Plans
Real Images

5. Location: Paratali , Narshingdi
Plant Name: Shouro Bangla 141KWp Solar Mini Grid.
Some significant observations
1. Due to the continuous increase of load ,overcurrent
fault has been arise.
2. No certain monitoring system for observing current
of each phase from the grid plant authority office.
3. Load current increase by some unexpected
interruption by the locality.

7. DC GRID
On DC solar grid, generation
voltage 48volt that is why
we need a DC-DC converter.
Which converted
generation voltage 48volt to
distribution voltage 220volt.
AC GRID
In AC solar grid system,
generation voltage is in DC.
Level is 48volt or 24volt etc.
So, we need DC to AC
inverter.

8. To protect the DC grid’s both transmission and
distribution side from different kinds of
electric fault.
There is no remote monitoring and control
system.

10.  Block Diagram:

11. Working Flow Diagram

12. Specification 5AModule 20AModule 30AModule
Supply Voltage(VCC) 5Vdc nominal 5Vdc nominal 5Vdc nominal
Measurement Range -5 to +5Amps -20 to +20Amps -30 to +30Amps
Scale Factor 185mV per Amp 100mV per Amp 66mV per Amp
Chip ACS712ELC-05A ACS712ELC-10A ACS712ELC-30A
Voltage at 0A VCC/2(Nominally
2.5Vdc)
VCC/2(Nominally
2.5Vdc)
VCC/2(Nominally
2.5Vdc)
Current Sensor (ACS712)

13. Specifications:
>>Microcontroller ATmega328
>>Operating Voltage: 5V
>>Digital I/O Pins: 14
>>Analog Input Pins: 8
>>DC Current Per I/O Pin: 40mA
>>Flash Memory: 32 KB
>>Clock Speed: 16 MHz

14. Specifications:
>>2.4Ghz worldwide free open ISM
band
>>Up to 2Mbps on air data rate
>>Maximum output power: +20dBm
>> operation voltage : 3.0-3.6V (3V3)
>> Transfer distance can reach 1000
meters @ 250 Kbps
>>Temperature range of -40 to
+80ºC

15. Server module name: PC Duino
Purposes of using server
1. Adds Reliability.
2. Gives proper scability.
3. Improves collaborations
4. Makes faster expansions
5. Allows Centralized and Automated Backup Systems

16. Principle of server implementation
1.Monitoring and recording the data .
2.Send it to the certain server.
3.Decoding the signal, it will show in the connected monitor with
the server.
4.Server will always be online.
pcDuino

17. Short distance
less expensive
Increased mobility
For low voltage level
Easily maintenance

19. Observing data from the server :

20. Output Curves:
Gradually increasing
the operating
current the
operating time of
the relay frequently
decreasing, which
very much similar
with the IDMT relay
behaviour.
X= Applied Current
Y=Operating Time

21. >> Design is applicable for any DC grid.
>>Ensured the protection of the DC grid transmission &
distribution side.
>>Applicable for reducing the unexpected interfering in
the DC grid line.

22. 1. Planning to upgrade the systems for any grids.
2. Making more cost effective.
3. Developing the project for controlling the phase line
from authority office after trip the certain connected
load.

24. THANK YOU ALL