The document summarizes the development of a double input DC-DC converter for renewable energy sources. The converter integrates two different voltage sources using a quasi Y-source converter and a boost converter connected in parallel. Simulation and hardware results show the converter can supply loads from 2.5W to 25W with efficiencies up to 70%. However, load sharing between the sources is uneven without control. Future work could involve closed loop control and load sharing strategies to better integrate distributed energy resources dynamically.

1. Double Input Boost/Y-Source DC-DC
Converter for Renewable Energy Sources
By-
Niteesh S Shanbog
PES1201702421
MTech, Dept. of
EEE
Guided by-
Mrs. Pushpa K. R
Assistant Professor
Dept. of EEE
MTech Project Presentation

2. Outline The Problem
Solution Proposal
Solution Implementation
Results
Future Scope

3. The Problem

4. Problem
statement
To develop a Multi-Input Converter to
meet the influxof Distributed Energy
Resources (DERs).
● Test for a Multi-Input Converter having
different topologies.
● Determine the Load Sharing Pattern
between the the sources in open loop.
● Ability for each source to independently
meet the load demand.

5. Growth of DERs
● Driven by push towards a
decentralised grid.
● Domesticadoption of solar, and
wind.
● Advancements in storage
technology.
● Emergence of new flexibility
options like V2G.
● Geopolitical compulsions
Source:Ministry of New and Renewable Energy; Mercom India Research

6. Multi-Input Converters
● Replace numerous converters.
● Interface different voltages.
● Maintain the unique advantage of each
individual converter[1].
● Higher reliability and efficiency.
Multi-Input
Converter
Series MIC Parallel MIC
Source:Khosrogorji, S., Ahmadian, M., Torkaman, H., & Soori, S. (2016). Multi-input DC/DC converters in connection with distributed generation units–A review. Renewable and
Sustainable Energy Reviews, 66, 360-379.

7. ➔ Domestic Photovoltaic systems integrated with battery storage technology[2].
➔ Hybrid Electric Vehicles employing batteries and ultracapacitors.
➔ Decentralised grids utilising V2G as an option to ramp up peak supply.
➔ Fuel-Cells, Solar, Wind integrated Microgrid setups.
Use cases
Source:Gavriş, Mihaela, Octavian Cornea, and Nicolae Muntean. "Multipleinput DC-DC topologies in renewable energy systems-A general review." 2011 IEEE 3rd International Symposium
on Exploitation of Renewable Energy Sources (EXPRES).IEEE, 2011.

8. The Solution

9. Double Input Converter
To develop a Double Input Converter which can safely integrate two different sources with different
voltages and supply a single load.
The Double Input Converter is composed of two distinct converter topologies:
1. The Quasi Y-Source DC-DC Converter - High voltage Gain at significantly lower shoot through
periods[3].
2. Boost Converter - Classic converter topology to ramp up the input voltage.
Source:Siwakoti, Yam P., Frede Blaabjerg, and Poh Chiang Loh. "Quasi-Y-source boost dc–dc converter." IEEE Transactions on Power Electronics 30.12 (2015): 6514-6519.

10. Construction of the Double Input Converter[4]
Connection to Output Sink
The parallel connection of
the PCSCs is connected to
the common output sink,
with its outgoing current
terminal tied to the positive
terminal of the output sink.
Identify whether the converter has a
PCSC or a PVSC
Both the Quasi Y-Source
Converter and the Boost
Converter represent a
Pulsating Current Source
Cell (PCSC), with a diode in
series.
Identify the type of
connection - Parallel or Series
If the PCSCs are connected in
series, the current which is
flowing through the
connected branch of the
boost converter will be
clamped by the pulsating
source. Hence, they are to be
connected in parallel.
Source:Liu, Yuan-Chuan, and Yaow-Ming Chen. "A systematic approach to synthesizing multi-input DC–DC converters." IEEE Transactions on Power Electronics 24.1 (2009):
116-127.

11. Double Input Converter

12. Operating Modes

13. Advantages of the proposed converter
● Ability to integrate two different sources.
● High gain of the Quasi Y-Source enables even sources with low voltages to supply the
load satisfactorily.
● The Quasi Y-Source Converter operates at a low duty cycles, thereby reducing the
conducting loss in the switch. This is significant, because the Quasi Y-Source is
basically used for sources which supply low voltage.

14. Implementation
● MATLAB Simulation
● Open Loop Hardware Model

15. Quasi Y-Source
Converter
Circuit Parameters
Boost Converter Double Input Converter
● Input Voltage for Quasi Y-Source
converter = 12V
● Input Voltage for Boost Converter =
48V
● Output Voltage = 48V
Switching Frequency = 20kHz
Input Inductors = 1mH
Turns Ratio of Transformer = 3:2:1
Output Capacitor = 470uF
DC Blocking Capacitors = 470uF and 150uF

16. MATLAB Simulation Simulation Block Diagram

17. MATLAB Simulation Gate Signals

18. MATLAB Simulation Output Voltage

19. Hardware Implementation
INPUT SOURCE 1
INPUT SOURCE 2
DOUBLE INPUT
CONVERTER
LOAD
CONTROLLER

20. Assumptions
● Constant Input Sources
● Constant Load
● No sudden change in the nature of supply

21. Hardware Implementation Controller
1 2 3 4

22. Hardware Implementation Hardware Model

23. Results

24. Efficiency of the Double
Input Converter
➔ Load varied from 2.5W to 25W
➔ Higher efficiency (upto 70%) is
achieved nearer to the rated
power.
➔ Low efficiency at low/light loads.
➔ Conduction losses dominate at low
loads.

25. Load Sharing between the
two converters
➔ Load varied from 2.5W to 25W
➔ Load is not shared equally.
➔ Absence of control strategy..
➔ Input source with larger voltage
supplies a majority of the load.

26. Load Sharing between the
two converters
➔ Load varied from 2.5W to 25W
➔ Load is not shared equally.
➔ Absence of control strategy..
➔ Input source with larger voltage
supplies a majority of the load.

27. Future Scope

28. Future Scope
➔ Closed Loop Control - To handle flexibilities and dynamic nature of
renewables.
➔ Control Strategy - To fix a primary source., explore various current
sharing strategies.
➔ Evaluate performance with different types of DERs.
➔ Development of bidirectional converters to allow integration of storage
devices.

29. References
[1] Khosrogorji, S., Ahmadian, M., Torkaman, H., & Soori, S. (2016). Multi-input DC/DC converters in connection with distributed
generation units–A review. Renewable and Sustainable Energy Reviews, 66, 360-379.
[2] Gavriş, Mihaela, Octavian Cornea, and Nicolae Muntean. "Multiple input DC-DC topologies in renewable energy systems-A general
review." 2011 IEEE 3rd International Symposium on Exploitation of Renewable Energy Sources (EXPRES). IEEE, 2011.
[3] Siwakoti, Yam P., Frede Blaabjerg, and Poh Chiang Loh. "Quasi-Y-source boost dc–dc converter." IEEE Transactions on Power
Electronics 30.12 (2015): 6514-6519.
[4] Liu, Yuan-Chuan, and Yaow-Ming Chen. "A systematic approach to synthesizing multi-input DC–DC converters." IEEE
Transactions on Power Electronics 24.1 (2009): 116-127.
[5] Alberkrack, J. H. "A simplified power supply design using the TL494 control circuit." ON Semiconductor, Phoenix, AZ, Application
Note, AN983/D (2002).

30. Questions?