High Gain DC-DC Converter Collaborative - The Ohio State ......V w3 V bat i w2 C 1 L m i w3 C 2 C 3...
1
Sandia National Laboratories is a multimission laboratory managed and operated by National Technology & Engineering Solutions of Sandia, LLC, a wholly owned subsidiary of Honeywell International Inc., for the U.S. Department of Energy’s National Nuclear Security Administration under contract DE-NA0003525. SAND No. ____________ S HV1 S HV2 S HV3 L lk i lm V dc i in S LV1 S LV3 i bat S LV2 S LV4 V w2 V w3 V bat i w2 i w3 L m C 1 C 2 C 3 C LV i lk V pri t 0 t 1 t 2 t 3 t 4 t 5 t 6 t 7 t 8 ON ON ON ON ON ON ON t 9 Circuit Operation Principles High Gain DC-DC Converter Collaborative The Ohio State University Design Zhining Zhang 1 , Boxue Hu 1 ,Yue Zhang 1 , Jin Wang 1 , Jacob Mueller 2 , Luciano Garcia Rodriguez 2 , Stan Atcitty 2 1 The Ohio State University, Columbus, OH 2 Sandia National Laboratories, Albuquerque, NM High-voltage side quasi-switched-capacitor circuit • Reduced switching device voltage stress: 2 3 V dc • Enhanced reliability of switching device operations • Reduced voltage stress of transformer winding (primary side): ± 1 3 V dc • Increased circuitry’s voltage conversion ratio • Reduced transformer winding turns and enhance the coupling between primary and secondary windings Low-voltage side transformer-interleaved circuit • Boosted voltage stress of transformer winding (V W2 +V W3 ): ±2V bat • Increased circuitry’s voltage conversion ratio • Reduced transformer winding turns • Reduced battery current ripples by interleaved operations (W2 and W3) ACKNOWLEDGEMENT: The authors wish to thank the US DOE Office of Electricity and Dr. Imre Gyuk for supporting this work. In FY20, based on literature survey results, a QSC transformer-interleaved circuit was proposed as the final circuit topology to fulfill the voltage gain and current ripple requirements. With this topology, soft switching analysis, preliminary circuit simulations and circuit power loss modeling has been conducted.Power-loss oriented circuit optimization is ongoing. In FY21, the circuit optimization and hardware prototyping will be finished. A fundamental challenge for battery storage in grid applications is that power systems invariably favor high-voltage/low-current operation, while electrochemical cells are naturally low-voltage/high-current devices. Isolated high-gain dc-dc converters may be used to overcome this issue, but designing converters with simultaneously high efficiency and high voltage gain over a realistic range of operating conditions is a difficult task. Isolated dc-dc converters based on high-frequency magnetic conversion links and multiple H- bridge switching structures (exemplified by the dual active bridge converter) are an attractive starting point for designing high performance power conversion systems. This class of converter presents a blank design canvas; new materials, components, circuit modifications, integration strategies, modulation schemes, and control systems all represent opportunities for performance improvement. The goal of this project is to leverage these potential areas of innovation to develop a novel converter design for a challenging set of performance specifications. This effort is part of a family of projects focused on advancing the state-of-the-art in isolated high gain dc-dc converter design. These projects share a common set of performance objectives but differ greatly in individual approach. Each unique solution represents a data point from within the space of design possibilities, and provides valuable insights on potential design synergies and areas for future exploration. Figure (1) – Circuit diagram of QSC transformer-interleaved circuit Parameter Value Input Voltage Range 380 V – 420 V (400 V nominal) Output Voltage Range 20 V – 33.6 V (24 V nominal) Rated Power ±1 kW (bi-directional) Efficiency >95% for both charge and discharge Battery Current Ripple <2 A peak-to-peak Table I – Converter Performance Specifications Background and Objectives Proposed Circuit Topology Preliminary Simulation Results Conclusion and Future Work Figure (2) – Operation waveforms of QSC transformer-interleaved circuit Figure (3) – Circuit simulation waveforms Parameter Value DC side voltage 400 V Battery side voltage 24 V Operation power 1000 W Circuit switching frequency 300 kHz Transformer turns ratio 16 : 3 : 3 Leakage inductance 4.46 μH Phase shift angle 35 o LV side capacitance 33 μF Duty ratio 0.5 Table 2 – Simulation Parameters • Phase-shift operation implemented to achieve operation power regulation • High voltage side: S HV1 switched in complementary with S HV2 and S HV3 with a 0.5 duty ratio • Low voltage side: S LV1 and S LV4 switched in complementary with S LV2 and S LV3 as a H-bridge with a 0.5 duty ratio • Device soft-switching achieved by transformer leakage inductance current • Interleaved operation of secondary side to achieve battery current ripple cancellation • Battery current: i bat =i w3 –i w2 Phase shift angle S HV1 S HV2, S HV3 S LV1, S LV4 S LV2 S LV3 V pri V w2 ,V w3 I lk & I Lm I w2 I w3 Time (s) SAND2020-9703 C
Transcript of High Gain DC-DC Converter Collaborative - The Ohio State ......V w3 V bat i w2 C 1 L m i w3 C 2 C 3...
Sandia National Laboratories is a multimission laboratory managed and
operated by National Technology & Engineering Solutions of Sandia, LLC,
a wholly owned subsidiary of Honeywell International Inc., for the U.S.
Department of Energy’s National Nuclear Security Administration under
contract DE-NA0003525.
SAND No. ____________
SHV1 SHV2
SHV3
Llk
ilm
Vdc
iin
SLV1
SLV3
ibat
SLV2
SLV4
Vw2
Vw3
Vbat
iw2
iw3LmC1
C2 C3
CLV
ilk
Vpri
t0 t1 t2 t3 t4 t5 t6 t7 t8
ON ON
ON
ON
ON
ONON
t9
Circuit Operation Principles
High Gain DC-DC Converter Collaborative The Ohio State University Design
Zhining Zhang1, Boxue Hu1, Yue Zhang1, Jin Wang1, Jacob Mueller2, Luciano Garcia Rodriguez2, Stan Atcitty2
1The Ohio State University, Columbus, OH 2Sandia National Laboratories, Albuquerque, NM
High-voltage side quasi-switched-capacitor circuit
• Reduced switching device voltage stress:23
Vdc
• Enhanced reliability of switching device operations
• Reduced voltage stress of transformer winding (primary side):±13
Vdc
• Increased circuitry’s voltage conversion ratio
• Reduced transformer winding turns and enhance the coupling between
primary and secondary windings
Low-voltage side transformer-interleaved circuit
• Boosted voltage stress of transformer winding (VW2 +VW3):±2Vbat
• Increased circuitry’s voltage conversion ratio
• Reduced transformer winding turns
• Reduced battery current ripples by interleaved operations (W2 and W3)
ACKNOWLEDGEMENT: The authors wish to thank the US DOE
Office of Electricity and Dr. Imre Gyuk for supporting this work.
In FY20, based on literature survey results, a QSC transformer-interleaved circuit was proposed
as the final circuit topology to fulfill the voltage gain and current ripple requirements. With this
topology, soft switching analysis, preliminary circuit simulations and circuit power loss modeling
has been conducted. Power-loss oriented circuit optimization is ongoing.
In FY21, the circuit optimization and hardware prototyping will be finished.
A fundamental challenge for battery storage in grid applications is that power systems
invariably favor high-voltage/low-current operation, while electrochemical cells are naturally
low-voltage/high-current devices. Isolated high-gain dc-dc converters may be used to
overcome this issue, but designing converters with simultaneously high efficiency and high
voltage gain over a realistic range of operating conditions is a difficult task.
Isolated dc-dc converters based on high-frequency magnetic conversion links and multiple H-
bridge switching structures (exemplified by the dual active bridge converter) are an attractive
starting point for designing high performance power conversion systems. This class of
converter presents a blank design canvas; new materials, components, circuit modifications,
integration strategies, modulation schemes, and control systems all represent opportunities
for performance improvement. The goal of this project is to leverage these potential areas of
innovation to develop a novel converter design for a challenging set of performance
specifications.
This effort is part of a family of projects focused on advancing the state-of-the-art in isolated
high gain dc-dc converter design. These projects share a common set of performance
objectives but differ greatly in individual approach. Each unique solution represents a data
point from within the space of design possibilities, and provides valuable insights on potential
design synergies and areas for future exploration.
Figure (1) – Circuit diagram of QSC transformer-interleaved circuit
Parameter Value
Input Voltage Range 380 V – 420 V (400 V nominal)
Output Voltage Range 20 V – 33.6 V (24 V nominal)
Rated Power ±1 kW (bi-directional)
Efficiency >95% for both charge and discharge
Battery Current Ripple <2 A peak-to-peak
Table I – Converter Performance Specifications
Background and Objectives
Proposed Circuit Topology
Preliminary Simulation Results
Conclusion and Future Work
Figure (2) – Operation waveforms of QSC transformer-interleaved circuit
Figure (3) – Circuit simulation waveforms
Parameter Value
DC side voltage
𝑉𝑑𝑐400 V
Battery side voltage
𝑉𝑏𝑎𝑡24 V
Operation power
𝑃𝑖𝑛1000 W
Circuit switching frequency
𝑓𝑠𝑤300 kHz
Transformer turns ratio 𝑁 16 : 3 : 3
Leakage inductance
𝐿𝑙𝑘4.46 µH
Phase shift angle
𝜑35o
LV side capacitance
𝐶𝐿𝑉33 µF
Duty ratio
𝐷0.5
Table 2 – Simulation Parameters
• Phase-shift operation implemented to achieve operation power regulation
• High voltage side: SHV1 switched in complementary with SHV2 and SHV3 with a 0.5
duty ratio
• Low voltage side: SLV1 and SLV4 switched in complementary with SLV2 and SLV3 as a
H-bridge with a 0.5 duty ratio
• Device soft-switching achieved by transformer leakage inductance current
• Interleaved operation of secondary side to achieve battery current ripple cancellation
• Battery current: ibat = iw3 – iw2
Phase shift angle 𝜑
SHV1
SHV2, SHV3
SLV1, SLV4
SLV2 SLV3
Vpri
Vw2, Vw3
Ilk & ILm
Iw2
Iw3
Time (s)
SAND2020-9703 C
