1. Steady State Analysis Of A Microgrid Connected To A Power System
Presentation by Program
FoS
School
Ramesh Paudel
EPSM
Energy
SERD

2. Presentation Outline Conventional Power System
Future Electric Power System
Distributed Generation?
Microgrid and Its Architecture
Objectives of the Study
Flowchart of the Methodology
Test Systems and Modes of Operation
Results
Conclusion

3. Conventional Power System

4. Conventional Power System
Pollution
67% Total Waste
Power Plant
33% delivered electricity
Fuel
100%
Line Losses 9%
T & D Loss = 0.9 kW
Generation
1 kW
End user
0.91 kW

5. Effects of Emission Pollutant Climate Change Local Effect
More underground fault conditions in older cables
Local Effect
Global Effect
NOx, SOx
Particulate Matter
CO2, CH4
Acid Rain
Smug
Green House Effect
More overhead damage due to harsh storms
Climate Change
Demand increases for heating & pumping in winter & air conditioning in summer

6. Future Electric Power System
Small Hydro
Off Shore Wind Farm
Solar Power
Plant
Hydro Power Station
Biomass
Low Emission Plant
Local Control Center
Wave Energy
Microgrid
Solar
Underground Cable

7. Distributed Generation?
Distributed or dispersed generation may be defined as a generating resource, other than central generating station, that is placed close to load being served, usually at customer site.
Advantages
Concern about climate change.
Improve power quality and system reliability.
Reduce transmission and distribution line losses.
Constraints on construction of new transmission lines.
Relatively low capital cost compared to centralized generation due to avoided T&D capacity upgrades.
Disadvantages
With faults in system, DG has to be disconnected from grid. Loads will be cut off from power.

8. Microgrid
“Microgrid” is an independent entity which combines loads and distributed generators and can be controlled locally instead of central dispatch of grid.
Microgrid follows grid rules and separates itself from distribution system during disturbances without harming integrity of distribution network.
Customers will be able to enjoy an uninterrupted power supply with enhanced reliability and better power quality thereby meeting their demand for power as well as heat.
From utility prospective MG helps in congestion management, manage local power requirement and voltage support and delay requirement of new power plants.

9. Microgrid ArchitectureHL
Sensitive Loads
Adjustable Loads
Shade-able Loads
Grid Supply A B C
Point of common coupling Static switch Reciprocating engine
Circuit breaker Heat load Fuel cell
Electronic interface PV panel Micro turbine
Electric wires Protection data Communication data HL

10. Objectives of the Study
Siting of MG within a distribution system.
To find optimal size DGs in MG.
Interaction between MG and distribution system during
Normal supply condition
Island operation.

11. Flow Chart of Methodology
Start
End
Read input data
Run distribution load flow
in base case.
Find suitable location of MG based
on loss sensitivity factor.
Find optimal size of DGs and their location in
MG using loss optimization technique.
Analyze performance of MG and distribution
system under various operating conditions.
Print results

12. Test Systems and Modes of Operation
IEEE 33 Bus System
IEEE 69 Bus System
2.378 MW MW
IEEE 33 Bus System with Microgrid Isolated from Distribution Network
IEEE 33 Bus System with Microgrid

13. Reactive power loss (kVAR)
Results
Loss Reduction
Feeder Loading Capacity
Sl no
Particular
Real power loss (kW)
Reactive power loss (kVAR) 1
Conventional system
211.2
143.21 2
MG connected to power system
113.51
96.81 3
Percentage reduction in loss
46.25
32.4
Loss reduction
93.69 kW
Network with MG
Generation saving kW
CO2 emission reduction 1109 ton/yr
Annual Energy saving 940 MWhr

14. Results
Voltage Profile

15. Conclusion
A methodology has been developed to identify a possible location of MG in a distribution system. Placement of DGs is done for optimal system loss.
System loss can be reduced nearly by 46% with the introduction of MG into distribution system. Less electricity to be generated and hence less emission.
Voltage profile of the system is greatly enhanced. Better performance of electrical devices.
Feeder loading capacity is increased. Postpone construction of new lines.
Isolated mode of operation of MG ensures an uninterrupted power supply to loads. Consumers can enjoy good quality of power supply without any interruption.

16. 6 11 7 4 5 3 9 13 14 2 10 1 8 12 Substations Solar Cells EDLC
D.G, Battery, Control 6 11 7 4 3 5 9 13 14 2 10 12 8 1

17. Thank you for your attention! WE HAVE ONLY ONE EARTH TO LIVE IN.
SAVE ENERGY.
WE HAVE ONLY ONE EARTH TO LIVE IN.