![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.](https://image.slidesharecdn.com/projectwireframes-190707082608/85/Double-Input-Boost-Y-Source-DC-DC-Converter-6-320.jpg)
![➔ 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.](https://image.slidesharecdn.com/projectwireframes-190707082608/85/Double-Input-Boost-Y-Source-DC-DC-Converter-7-320.jpg)
![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.](https://image.slidesharecdn.com/projectwireframes-190707082608/85/Double-Input-Boost-Y-Source-DC-DC-Converter-9-320.jpg)
![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.](https://image.slidesharecdn.com/projectwireframes-190707082608/85/Double-Input-Boost-Y-Source-DC-DC-Converter-10-320.jpg)
![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).](https://image.slidesharecdn.com/projectwireframes-190707082608/85/Double-Input-Boost-Y-Source-DC-DC-Converter-29-320.jpg)
Double Input Boost/Y-Source DC-DC Converter
- 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.
- 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?
Editor's Notes
- #6: The need for MICs increase because of the rapid growth of adoption of DERs. This growth is mainly due to Decentralised Grid Domestic adoption of solar - reducing prices, easy availability, possibility to go off-grid. Pressure to increase the share of renewables in the existing grid, removing the dependence on oil Storage Technology - Advancements in material science, new types of battery technologies like Lithium Ion V2G, EV
- #7: Replace numerous converters. Interface different voltages. Maintain the unique advantage of each individual converter. Higher reliability and efficiency. Sources connected in parallel must carry the same current. This is not feasible always and this is where MICs come into play. MICs convert the different input voltages with different currents into a single output voltage. To supply the load.
- #11: There are different strategies for synthesizing the MICs which vary based on the types of the input and output of the converters. The input port might be voltage source or current source and also the output port might be current load or voltage load. In this paper, we will focus on the current source– voltage load. In this converter, firstly, a high frequency pulse-train current waveform is produced by the switch and inductor and then goes through the voltage load. Hence, the boost dc-dc converter is comprised of two cells: a Pulsating Current-Source (PSC) and a voltage sink.
- #12: The Y-source network has earlier been tested as a dc–dc converter. Its gain has indeed been proven higher than other classical impedance networks even with a smaller shoot-through duty cycle used. The proposed converter is again a high-voltage boost converter implemented with high-frequency magnetics, but with a continuous input current drawn from the source. It is capable of handling a wide range of input voltage, while not increasing voltage stresses sustained by its components. The proposed converter is thus more suitable for renewable power conditioning systems. In addition, its two capacitors are placed such that they block dc current from flowing through the coupled inductor, and hence preventing its core from saturation.
- #22: Synchronizing multiple oscillators in a common system is conveniently achievable due to the flexible architecture of the TL494. The internal oscillator in the TL494 is used only for the generation of a saw-tooth waveform on the timing waveform. This can be to constrain the oscillator on the slaves by maintaining a compatible saw-tooth waveform externally to the timer capacitor terminal. Terminating the $R_T$ terminal to the reference supply will constrain the internal oscillator of the slave TL494. The buffer circuit prevents the loading of the source. If the load to a voltage source is a low value, it practically shorts the source and draws too much current from the source.So by cascading a buffer after a source provides a division of labour- the source only generated the correct voltage and the buffer provides the demanded current keeping the voltage constant AND without loading the source as the buffer has very high input impedance, it draws negligible current from the original source, thereby preventing loading. A gate driver is then used to accept low power control signals from a controller and amplify it into a larger current output which drives the power MOSFET.
- #25: V-I overlap losses are proportional to the input voltage, load current and switching frequency and occur due to the V-I overlap region that is seen in converters with rapid switching cycles. But at low loads, the conduction losses which are caused due to current ripples dominate the overlap losses as the power dissipated due to current ripples remain same whereas the overlap losses reduce due to low load currents. Under light loads, the gate drive losses which occur due to the charging and discharging the gate capacitance dominate the load.
- #26: The maximum efficiency of the quasi-Y-source converter has also been read as 93.9% at 10% duty ratio when the load is 200 W. It falls to 88% at the same load when the duty ratio is raised to 15%. This drop in efficiency at a high shoot-through duty cycle is presently a concern faced by all impedance-source converters. Its cause is mainly due to the flow of large shoot through current, whose loss contribution can be reduced by using better graded wires for the coupled magnetics and busbars for the converter on the printed circuit board.
- #27: The boost converter which has 2 batteries supplies the majority of the load as the output load is increased. This is a potential problem because if one of the converters fails, then the other converter will go from supplying a percentage of the load to supplying the full load. During this time the voltage will droop in the absence of a closed loop control system. The transient will be even more severe if the converter which is supplying a higher percentage of the load fails.
- #29: An interesting method of current sharing will be to choose one converter as the master. This master converter will be employed with intelligent driver controls and will supply the base load. The slave controller will boost the voltage to meet the dynamic power requirements. Current sharing strategies must be developed so that both the converters supply a pre-determined share of the load. This is essential so that both the converters age at the same rate and replacement will be easier. Advances in storage technology, as well as the availability of cheap second-hand batteries disposed of EV's, will increase the use of batteries as a part of the power grid. Higher power production from renewables will be used to store the batteries which will then be used during peak loads.