Micro grid Power Management scheme for Photovoltaic and Battery Systems with Dual input Boost DC-DC converter and VSC

1. 1
Project Title
Microgrid Power Management scheme for Photovoltaic and
Battery Systems with Dual input Boost DC-DC converter and
VSC

2. Contents
1. Abstract
2. Objective
3. Proposed system block
diagram
4. Control Techniques
5. Results and Discussions
6. Conclusion
Department of Electrical & Electronics Engineering
Kakinada Institute of Engineering and Technology

3. 1. Abstract
Department of Electrical & Electronics Engineering
Kakinada Institute of Engineering and Technology
This project proposes a control and power management system for PV-battery-based
hybrid micro grids with both AC and DC buses using dual input boost DC-DC converter and
VSC, for both grid-connected and islanded modes. The steady state performance of the single
stage dual input boost DC-DC converter has been explained. Battery is usually employed in
Photovoltaic (PV) system with converter to mitigate the power fluctuations due to the solar
irradiance changes. The proposed system is successful in regulating the DC and AC bus
voltages and frequency stably, controlling the power and voltage of each unit flexibly, and
balancing the active and reactive power flows in the micro grid system automatically under
different operating conditions. MATLAB simulation studies are carried out to verify the
performance of the proposed system.

4. 3. Objective
Department of Electrical & Electronics Engineering
Kakinada Institute of Engineering and Technology
• Implementing dual input boost DC-DC converter for PV-battery-based hybrid
micro grids with both AC and DC buses.
• Study the operation of dual input boost DC-DC converter
• Study the performance of the proposed system(PV-battery-based hybrid
system).
• Observe the active and reactive power flows in the micro grid system
automatically under different operating conditions.

5. Department of Electrical & Electronics Engineering
Kakinada Institute of Engineering and Technology
4. Proposed system

6. Department of Electrical & Electronics Engineering
Kakinada Institute of Engineering and Technology
4. Proposed system
1. Solar PV system
2. Dual input DC-DC converter
3. Inverter
4. Control and power management system

7. Department of Electrical & Electronics Engineering
Kakinada Institute of Engineering and
Technology
4. Proposed system
Solar PV System
V–I and P-V characteristic of PV
module under different solar
irradiance and at 25o C with MPPT
points in strings.

8. Department of Electrical & Electronics Engineering
Kakinada Institute of Engineering and
Technology
4. Proposed system
Solar PV System
PV array power
and current vs.
array voltage.

9. Department of Electrical & Electronics Engineering
Kakinada Institute of Engineering and
Technology
4. Proposed system
Dual Input DC-DC Boost converter

10. Department of Electrical & Electronics Engineering
Kakinada Institute of Engineering and
Technology
4. Proposed system
Dual Input DC-DC Boost converter
Different Circuit states in Dual Input Boost Mode:
(a) Charging of inductor by solar PV module
(b) Charging of inductor by battery
(c) Discharge of inductor to DC bus with battery as power
source
(d) Discharge of inductor to DC bus with solar PV module
as power source

11. Department of Electrical & Electronics Engineering
Kakinada Institute of Engineering and
Technology
4. Proposed system
Dual Input DC-DC Boost converter
(a) Charging of inductor by solar PV module

12. Department of Electrical & Electronics Engineering
Kakinada Institute of Engineering and
Technology
4. Proposed system
Dual Input DC-DC Boost converter
(b) Charging of inductor by battery

13. Department of Electrical & Electronics Engineering
Kakinada Institute of Engineering and
Technology
4. Proposed system
Dual Input DC-DC Boost converter
(c) Discharge of inductor to DC bus with battery as
power source

14. Department of Electrical & Electronics Engineering
Kakinada Institute of Engineering and
Technology
4. Proposed system
Dual Input DC-DC Boost converter
(d) Discharge of inductor to DC bus with solar PV module as
power source

15. 15
4. Proposed system
Inverter
A three-phase inverter is used to convert DC to AC power, interfacing the DC and AC sides.

16. 4. Control and power management system
Kakinada Institute of Engineering and
Technology
Department of Electrical & Electronics Engineering
a) PV Array MPPT Controller
b) Dc-dc converter controller
c) Inverter Controller

17. Kakinada Institute of Engineering and
Technology
Department of Electrical & Electronics Engineering
i. PV Array MPPT Controller
perturb and observe (P&O) algorithm is selected for the proposed system
4. Control and power management system

18. Kakinada Institute of Engineering and
Technology
Department of Electrical & Electronics Engineering
i. Dc-dc converter controller
4. Control and power management system

19. Kakinada Institute of Engineering and
Technology
Department of Electrical & Electronics Engineering
i. Inverter Controller
4. Control and power management system

20. 20
Simulation Diagram

21. 21
5. Simulation Results and Discussions
Case A-1: The first case is the normal operation situation of the PV-battery system in grid-
connected mode, when the battery is fully available for power balancing (10% < SOC< 90%).
Fig. 7. Grid-connected mode Case A-1: (a)
power flows and (b) voltage Fig. 1. (b)
values of the PV-battery system

22. 22
5. Simulation Results and Discussions
Case A-2: As the battery is charged, the SoC will keep increasing. When the battery
SoC is greater than 90 %, CAPMS will stop charging the battery and send the surplus
power to the grid. Whenever the demand increases, the energy stored in the battery will
be released to complement the change.
Grid-connected mode Case A-2:
power flows of the PV-battery
system.

23. 23
5. Simulation Results and Discussions
Case A-3: There is also situation where the SoC of battery has reached the upper
limits (90 %), however, the maximum power provided by the PV array is more than
the demands and loads. In this case, since the battery has been
fully charged, and if the grid cannot absorb the excess power from PV array, CAPMS
will switch the operating mode of PV from MPPT to power-reference mode to
balance the system, as is presented in Fig. 9 (Case A-3-1)
Fig. 9. Grid-connected mode
Case A-3-1: PV array in
power-reference mode.

24. 24
Fig. 11. Grid-connected mode Case A-4: the
PV-battery system is receiving
power from the grid after 2.2 s.
Case A-4: The power flow in the inverter is bidirectional, i.e., when necessary, the PV-battery system can
request power from the grid. For instance, when there is available power from the grid and the PV-battery
system has more demand than generation, the CAPMS can reverse the power through
the inverter to supply the system.
5. Simulation Results and Discussions

25. 8. CONCLUSION
Kakinada Institute of Engineering and
Technology
Department of Electrical & Electronics Engineering
This paper proposes a control and power management system (CAPMS) for hybrid
PV-battery systems with both DC and AC buses and loads. The presented CAPMS is
able to manage the power flows in the converters of all units flexibly and effectively,
and ultimately to realize the power balance between the hybrid microgrid system and
the grid. DC and AC buses are under full control by the CAPMS, providing a stable
voltage environment for electrical loads. This also allows additional loads to access
the system without extra converters, reducing operation and control costs. Numerous
simulation case studies are carried out.

26. THANK YOU
ANY QUESTIONS?