Further details at : www.statconenergiaa.com . The Presentation gives a basic working block diagram of the solar Off Grid Inverter and it clears the basic confusion between Off Grid systems and Off grid inverters.

1. SOLAR OFF GRID INVERTER SYSTEM
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2. Solar present, Grid available.
Battery Charged through
Solar MPPT charger Only,
Load supplied through Grid.
AC LOADS
(Priority)
P1=0
AC LOADS
(Others)
P2 P3
P gr=P2+P3
GRID
CHARGING
INTERLOCK
DG SET
(OPTIONAL)
OFF GRID SOLAR POWER SYSTEM
CONDITION # 1
P gr
P so
P dg
P ba = P so
©2015 STATCON ENERGIAA PVT LTDwww.statconenergiaa.com

3. AC LOADS
(Priority)
AC LOADS
(Others)
GRID
INTERLOCK
CHARGED
Solar present, Grid available.
Battery Full Charged condition, Priority
Load supplied only through Solar.
Secondary Load Through Grid
separately
CONDITION # 2
DG SET
(OPTIONAL)
P1=P so
P2=P so P3=P gr
P gr
P so
P dg
P ba = 0
P gr=P3
OFF GRID SOLAR POWER SYSTEM
©2015 STATCON ENERGIAA PVT LTDwww.statconenergiaa.com

4. AC LOADS
(Priority)
AC LOADS
(Others)
GRID
INTERLOCK
CHARGING
Solar NOT present, Grid Available.
Battery Charged through GRID, Load
supplied through Grid.
CONDITION # 3
DG SET
(OPTIONAL)
P1
P2 P3
P gr=Pba +P2+P3
P gr
P so = 0
P dg
P ba
OFF GRID SOLAR POWER SYSTEM
©2015 STATCON ENERGIAA PVT LTDwww.statconenergiaa.com

5. AC LOADS
(Priority)
AC LOADS
(Others)
GRID
INTERLOCK
DISCHARGING
Solar NOT present, Grid NOT
available.
Priority Load supplied through
Battery.
CONDITION # 4
DG SET
(OPTIONAL)
P1=P ba
P3
P gr
P so
P dg
P ba = P2
No Interruption To LOAD during
changeover!
OFF GRID SOLAR POWER SYSTEM
©2015 STATCON ENERGIAA PVT LTDwww.statconenergiaa.com

6. AC LOADS
(Priority)
AC LOADS
(Others)
GRID
INTERLOCK
CHARGING
©2015 STATCON ENERGIAA PVT LTDwww.statconenergiaa.com
CONDITION #5
Solar NOT present, Grid NOT
available.
Battery level lower than Pre-set then
Charged through DG Set, All Load
supplied through DG Set.
DG SET
(OPTIONAL)
P1=0
P2 P3
P dg=Pba+P2+P3
P gr
P so
P dg
P ba = P so
OFF GRID SOLAR POWER SYSTEM

7. ADVANTAGES
1. Most trusted and long running technology for solar inverters
2. Maintains the battery life by using solar to reduce its charging and discharging cycles
compared to a non-solar inverter battery system.
3. Provides uninterrupted supply to the primary loads of the household
4. Can run the loads from the available sources according to the priority of the sources
in the algorithm.
5. Reduces diesel consumption by not running DG all the time.
DISADVANTAGES:
1. If the battery is already charged and the loads are few, then the excess power
produced from the Solar panels is wasted.
2. Cannot export to grid
3. No power sharing between sources. Different sources supply to different loads at
the same time.
4. Battery life not as good ( as Hybrid Inverters generally ) and it dies out early.

8. www.statconenergiaa.com
PH: +91 120 2427310/11
EMAIL: info@statconenergiaa.com