Slide 1: A Hybrid Voltage Regulation Transformer Based on Interline Power Converters
A Hybrid Voltage Regulation Transformer Based on Interline Power Converters Yafeng Wang, Tiefu Zhao Department of Electrical and Computer Engineering Energy Production and Infrastructure Center (EPIC) University of North Carolina at Charlotte Paper Number: 1058
Slide 2: Table of Contents
Table of Contents • Introduction • Proposed Hybrid Voltage Regulation Transformer • Simulation Results • Prototype Test Results • Conclusion 2 of 18
Slide 3: Introduction
Introduction • Conventional Step Voltage Regulator (SVR) – Auto-transformer based configuration – Preventive transformer and equalizer windings to balance the branch current – Increase and decrease the tap position to regulate load voltage at the distribution stage • Issues and Challenges – Arcing w
Slide 4: Table of Contents
Table of Contents • Introduction • Proposed Hybrid Voltage Regulation Transformer – Topology and Operation Principle – Converter Control and Operation • Simulation Results • Prototype Test Results • Conclusion 4 of 18
Slide 5: Proposed Hybrid Voltage Regulation Transformer: Circuit Topology
Proposed Hybrid Voltage Regulation Transformer • Circuit Topology – Additional winding placed in series with the secondary winding – Two series transformers are connected in series with top and bottom branches – An interline back-to-back power converter connects two series transformers • Operation P
Slide 6: Proposed Hybrid Voltage Regulation Transformer: Converter Control
Proposed Hybrid Voltage Regulation Transformer • Converter Control – Rectifier regulates the DC bus voltage with unity power factor – Inverter regulates the load voltage Rectifier Control Algorithm Inverter Control Algorithm 6 of 18
Slide 7: Proposed Hybrid Voltage Regulation Transformer: Operation Principle
Proposed Hybrid Voltage Regulation Transformer • Operation Principle – At the nominal source voltage, no regulation is required. Top and bottom branches share the load current equally and the voltages on top and bottom windings are the same. – The maximum power rating of the converter in the interli
Slide 8: Table of Contents
Table of Contents • Introduction • Proposed Hybrid Voltage Regulation Transformer • Simulation Results • Prototype Test Results • Conclusion 8 of 18
Slide 9: Simulation for Function Validation
Simulation Results • Simulation for Function Validation – The simulation specifications are listed in Table I, II and III for comcomparison. – The proposed interline solution requires half of Conventional Series Solution the maximum converter power than the series solution. TABLE II. P ROPOSED HYBIR
Slide 10: Simulation for Function Validation
Simulation Results • Simulation for Function Validation – With the proposed control algorithms, the top and bottom winding voltage and current change accordingly based on different primary winding voltage deviations. – The operation principles and control algorithms are verified by the simulation re
Slide 11: Converter Power Loss and Overall Efficiency Comparison
Simulation Results • Converter Power Loss and Overall Efficiency Comparison – In PLECS simulation, IGBT (IGW60T120) rated at 1200V and 60A is selected. – The rectifier and inverter losses are highly related to the current flowing through the converter. So, the converter power loss of the proposed in
Slide 12: Converter Power Loss and Overall Efficiency Comparison
Simulation Results • Converter Power Loss and Overall Efficiency Comparison – The rectifier and inverter power capacity can be lowered to half compared to the conventional series voltage compensation solution, which saves the cost of the converter module. – The voltage regulation transformer overall
Slide 13: Table of Contents
Table of Contents • Introduction • Proposed Hybrid Voltage Regulation Transformer • Simulation Results • Prototype Test Results • Conclusion 13 of 18
Slide 14: Prototype and Specifications
Prototype Test Results • Prototype and Specifications – A scaled-down prototype is developed in the lab to verify the operation principle. – The prototype design specifications are listed in Table IV. TABLE IV. P ROTOTYPE DESIGN SPECIFICATIONS Parameter Value Source voltage 72 V Nominal load voltage
Slide 15: Prototype Test
Prototype Test Results • Prototype Test – Test condition: the source voltage steps down from 72V nominal voltage to 60V which is at the regulation limit. – Test result: the load voltage remains being regulated at 72V. – The top branch current Itop increases while the bottom branch current Ibot decre
Slide 16: Table of Contents
Table of Contents • Introduction • Proposed Hybrid Voltage Regulation Transformer • Simulation Results • Prototype Test Results • Conclusion 16 of 18
Slide 17: Conclusion
Conclusion • A hybrid transformer based on interline power converters is proposed for voltage regulation. • The operation principles are analyzed and validated by the simulation results. A scale-down prototype is developed, and the operation principle is validated by the hardware test results. • The
Slide 18: Thanks!
Thanks!