EPE Association: EPE 2019 - DS1d: Advanced Power Converter Topologies I

EPE 2019 - DS1d: Advanced Power Converter Topologies I
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 2019 ECCE Europe - Conference > EPE 2019 - Topic 02: Power Converter Topologies and Design > EPE 2019 - DS1d: Advanced Power Converter Topologies I

   [return to parent folder]

   A FAMILY OF MODIFIED ZETA-CONVERTERS WITH HIGH VOLTAGE RATIO FOR SOLAR-PV SYSTEMS
By Boris AXELROD [View]
[Download]

Abstract: This paper proposes a new family of single-switching DC-DC converters. The proposed converters are based on the classical Zeta-converter combined with two versions of switched inductors/switched capacitors structures. Analysis of the circuits made it possible to choose the most effective variants in terms of increasing the voltage gain. A detailed analysis of the best of the proposed schemes allowed to obtain graphs of the dependence of the voltage gain on the value of the duty cycle in the continuous and discontinuous current modes. Values of voltage stresses on the semiconductor devices are estimated. Theoretical expectations are confirmed by experimental results.

   A High-Efficiency DC-DC Converter with Wide Voltage Gain Range
By Fuqiang HAN [View]
[Download]

Abstract: A high-efficiency DC-DC converter with wide voltage gain range is presented in this paper. Itemploys two auxiliary switches to control the equivalent resonant tank, and thus exhibits adaptiveresonant characteristics for diverse situations. The input voltage varies from 80V to 600V and theoutput voltage is constant at 400V. The highest efficiency is 97.93\%.

   A Single-Phase Common-Ground-Type Boost Inverter for Photovoltaic Applications
By Minh-Khai NGUYEN [View]
[Download]

Abstract: This paper proposes a new single-phase inverter topology with common-ground for photovoltaic (PV) applications. The proposed inverter has the major features as the same ground between dc input and ac output voltage, voltage buck/boost capability and shoot-through immunity. The theoretical analysis and PWM method for the introduced inverter are discussed. A prototype based on a DSP TMS320F280049C was set up to confirm the performance of the introduced inverter. Simulation and experimental results are shown to validate the theoretical analysis and effectiveness of introduced inverter. The experimental results matched the theoretical analysis and simulation results.

   A Smart Control Method based on Phasor Diagram for Voltage-Type PWM Rectifier with High Power Factor and Constant DC-link Voltage
By Shinji KATO [View]
[Download]

Abstract: A smart control method based on the phasor diagram for a voltage-type PWM rectifier is proposed in this paper. The proposed method uses no PI controller in order to produce the high power factor and the constant DC-link voltage. From simulation results, we can realize the constant DC-link voltage of 300\,V, 600\,V, 900\,V or 1000\,V and the high power factor over 0.98.

   A Study on DC-Link-Type Quasi-Switched-Boost Inverters with Improved Voltage Gain
By Minh-Khai NGUYEN [View]
[Download]

Abstract: The DC-link type quasi-switched boost inverters (DCL-qSBIs) are known as one of impedance-source inverters with low voltage stress on their additional switch, diode, and capacitor. However, the voltage gain of DCL-qSBIs is still low. This paper presents DCL-qSBIs with a modified PWM control strategy. The modified PWM control strategy based DCL-qSBIs improve voltage gain, reduce the conduction loss, and decrease the voltage stress of devices in the switched-boost network. The operating principle of DCL-qSBIs is presented. The 1 kVA-prototype three-phase DCL-qSBI and quasi-Z-source inverter (qZSI) is built to evaluate the performance of the inverters at output voltage ratio of 1.05 to 1.6. The measured efficiency of DCL-qSBI is 0.5 to 1\% higher than that of the qZSI at all powers and boost levels tested.

   Class-E/?2 6.78 MHz HD-GiT-GaN based Amplifiers for WPT Systems
By Martin SCHIESTL [View]
[Download]

Abstract: In this work, the influence of the load variation on the performance and voltage stress of high frequency zero voltage switching Class-E and Class-?2 amplifier with GaN devices in the power range up to 100 W is investigated. With several transient simulations a window of efficient operation for various amounts of loads is found. This proposed procedure can be used for various kinds of amplifiers in order to compare their suitability for different loads. In addition, the individual switch terminal waveforms are checked by their conformity between measurement and simulation. This leads to an improved selection process for the switch to further reduce losses. The converters are driven at a ISM band frequency of 6.78 MHz used in Wireless Power Transfer Systems based on the Air-Fuel standard. The proposed amplifiers exhibit efficiency up to 95\%.

   Comparative Analysis on Gain Feature between CLTC and CDT-LC
By Bo CHEN [View]
[Download]

Abstract: A resonant DC-DC converter with dual-transformer structure is proposed. The converter improves the efficiency and gain characteristics. It has the ability to achieve wide range voltage regulation in a narrow frequency range. At the same time, a simplified method of double transformers and its gain characteristics are analyzed in details. Finally, a 2.5 kW prototype is built to verify the theoretical analysis, and the maximum efficiency is 97\%.

   Design and verification of Compact Inductor for Interleaved AC/DC Converter
By Gopal MONDAL [View]
[Download]

Abstract: Interleaving concepts with coupled inductors can be utilized for the reduction of passive component size, losses, and material cost. With coupled inductors, not all harmonics are attenuated and additional filter stages may be necessary. The paper presents an inductor designed to reduce both switching harmonics circulating within the coupled inductor as well as higher order harmonics injected into the grid. Analytical equations are derived for both conventional and the proposed inductors to show the benefits and the results are demonstrated with a lab prototype.

   Discussion on Loss Breakdown of 99.6\% Efficiency Two Battery HEECS Inverter
By Satoshi NAKAZAKI [View]
[Download]

Abstract: A very high efficiency HEECS topology inverter was proposed at ECCE2018, and after several modifications a very high efficiency 99.6\% is observed at approximately 2.3 kW output. In this paper, the loss breakdown is summarized and the possibility for the higher efficiency is discussed based on the loss analysis.

   Hybrid Alternate-Common-Arm Converter With Director Thyristors--Impact of Commutation Time on the Active-Power Capability
By Panagiotis BAKAS [View]
[Download]

Abstract: This paper investigates the impact of the thyristor commutation time on the peak currents and the activ-power capability of the hybrid alternate-common-arm converter (HACC). This converter employs director thyristors for the alternate connection of a common arm in parallel to the main arms. The parallel connection enables current sharing among the arms, which allows the HACC to transfer higher output power without increasing the peak arm current. It is shown that the active-power capability of the HACC is doubled for a certain current-sharing factor, which, however, is altered by the thyristor commutation time. Therefore, the impact of the commutation time on the active-power capability of the HACC is investigated theoretically. Finally, this analysis is verified by simulation results.

   Loss and Thermal Analyses for Modular Multilevel Converters
By Waqas ALI [View]
[Download]

Abstract: A modular multilevel converter exhibits large loss and temperature differences within a submodulewhen operated with a power factor close to unity. It has been shown that these temperaturedifferences can be decreased by implementing low loss modulation techniques and circulatingcurrent control, increasing reliability and lifetime.

   Low Frequency Mode Operation for Direct ac-ac Modular Multilevel Converter Systems. A Comparison of M3C and Hex-Y Topology.
By Pawel BLASZCZYK [View]
[Download]

Abstract: Modular Multilevel Converters (MMC) are power electronics systems used for energy conversion. Onetopology of MMC is Cascaded MMC characterized by series connection of cells. Each cell canprovide at least two different voltage levels. Resulting voltage in the converter arm is a sum of celloutput voltages.Depending on the application, converters can be divided by number of phases in interconnected systems.One of the applications is 3-phase to 3-phase ac-ac power conversion found e.g. in motor drives, powergeneration or grid frequency changers. In case there is no intermediate DC link between input andoutput, subgroup called direct-MMC can be distinguished. Following family includes Matrix Converter(M3C), Hexverter and Hex-Y.One of the challenging operation points for direct AC-AC MMC is a low frequency mode. In case ofrequired non-zero torque at low speed, module oversizing is necessary. An example applications with flattorque-speed characteristics are rolling / mining applications, hydro power generators or geralesswind generators.In following paper, low frequency mode with non-zero load torque is being analyzed for two of aforementionedtopologies: proposed by author Hex-Y topology and M3C used as a reference (due to identicalnumber of branches). Control algorithm providing given output voltages and currents plus equal branchenergy sharing has been described in detail.Control loop design for Hex-Y has been verified using Hardware in-the-loop simulator.

   Modulation limit of bootstrap power supply circuits: case study of a three level T-type converter
By Nicklas CHRISTENSEN [View]
[Download]

Abstract: A bootstrap power supply is used to reduce the number of DC/DC converters needed for supplying the gate drivers. The advantage of a bootstrap is the reduction of size and cost for gate driver circuitry. The disadvantages is a modulation index limit. A modulation index limit can be compensated for, by increasing the DC-link voltage and thereby raising switching losses. It is therefore critical to accurately determine the modulation index limit, to prevent excessive losses, obtain safe operation and to evalu- ate the applicability of a bootstrap. The design rules of a bootstrap currently relies on rules of thumb estimations, generally underestimating the modulation index limit. In this paper a new generic method for calculating the modulation index limit is presented. The method takes on-state resistance, switching states and output current into consideration. The method is validated based on a proposed bootstrap cir- cuit for a three level T-type converter. The proposed circuit achieves equivalent charging states as a half bridge bootstrap.

   New Multilevel Inverter Topology with Reduced Component Count
By Ahmed SALEM [View]
[Download]

Abstract: This paper introduces a new topology of modular multilevel inverters, being suitable in medium and high voltage applications. As compared to the existing circuits, the proposed topology has advantages of high `levels/components' ratio, increasing the output voltage levels without increasing the voltage stress across the used switches, structure simplicity, isolation features, and modularity. These merits allow it to fit well in high-reliability medium-power applications, which require fast troubleshooting and maintenance flexibility. Operating principles of the proposed scheme are detailed in low frequency and pulse width modulation. Simulation and experimental results validate the effectiveness of the circuit under different modulation and load conditions. Further, a comparative study between the proposed topology and other existing multilevel topologies was conducted and summarized in this paper.

   Optimized Dual Two-Level Inverter for Safe and Reliable Operation of Machines with Superconductive Stator Windings
By Johannes BUEDEL [View]
[Download]

Abstract: This paper aims to present an optimized inverter topology, based on the dual two-level inverter, for feeding an open-end winding electrical machine with superconductive stator windings and a superconductive rotor. In order to achieve a high torque density, the stator windings are built of several superconducting tapes being in parallel. One inverter of the dual two-level inverter is equipped with powerful IGBT semiconductors and supplies the machine with energy. The second inverter is a low voltage MOSFET inverter that monitors the superconductor resistance (quench detection) and balances the current on the parallel superconductive tapes for guaranteeing an optimum operation with respect to the superconductive losses.

   Quasi-Two-Level Operation of a Five-Level Flying-Capacitor Converter
By Sidney GIERSCHNER [View]
[Download]

Abstract: This paper deals with the quasi-two-level operation of a five-level Flying-Capacitor converter.The combination of the quasi-two-level operation and multilevel converters enables several opportunities.The series connection of low-voltage devices allows higher switching frequencieseven at high DC-link voltages. The use of intermediate levels decreases the dv/dt of the outputvoltage during the switching transients and improves the voltage spectrum. Furthermore,regarding the flying capacitors, the installed capacitance required can be significantly reduced.The redundant switching states are usually used to balance the capacitor voltages. However,this can be associated with enormous complexity, especially with a high number of levels. Thispaper considers two methods of voltage balancing for the quasi-two-level operation, which dowithout the redundant switching states and are based solely on the adaptation of the dwell timesof the individual intermediate levels. The first considers the flying capacitors separated so thatthe change of the dwell time happens independently. However, this leads to a variable dv/dtof the output voltage. The second method considers all flying capacitors of a phase togetherand assigns the dwell time according to the capacitor voltages. This results in an approximatelyconstant dv/dt of the output voltage.The functionality of the quasi-two-level operation and the two balancing methods are explainedand confirmed by simulation.

EPE 2019 - DS1d: Advanced Power Converter Topologies I
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 2019 ECCE Europe - Conference > EPE 2019 - Topic 02: Power Converter Topologies and Design > EPE 2019 - DS1d: Advanced Power Converter Topologies I
	[return to parent folder]

	A FAMILY OF MODIFIED ZETA-CONVERTERS WITH HIGH VOLTAGE RATIO FOR SOLAR-PV SYSTEMS By Boris AXELROD	[View] [Download]
Abstract: This paper proposes a new family of single-switching DC-DC converters. The proposed converters are based on the classical Zeta-converter combined with two versions of switched inductors/switched capacitors structures. Analysis of the circuits made it possible to choose the most effective variants in terms of increasing the voltage gain. A detailed analysis of the best of the proposed schemes allowed to obtain graphs of the dependence of the voltage gain on the value of the duty cycle in the continuous and discontinuous current modes. Values of voltage stresses on the semiconductor devices are estimated. Theoretical expectations are confirmed by experimental results.

	A High-Efficiency DC-DC Converter with Wide Voltage Gain Range By Fuqiang HAN	[View] [Download]
Abstract: A high-efficiency DC-DC converter with wide voltage gain range is presented in this paper. Itemploys two auxiliary switches to control the equivalent resonant tank, and thus exhibits adaptiveresonant characteristics for diverse situations. The input voltage varies from 80V to 600V and theoutput voltage is constant at 400V. The highest efficiency is 97.93\%.

	A Single-Phase Common-Ground-Type Boost Inverter for Photovoltaic Applications By Minh-Khai NGUYEN	[View] [Download]
Abstract: This paper proposes a new single-phase inverter topology with common-ground for photovoltaic (PV) applications. The proposed inverter has the major features as the same ground between dc input and ac output voltage, voltage buck/boost capability and shoot-through immunity. The theoretical analysis and PWM method for the introduced inverter are discussed. A prototype based on a DSP TMS320F280049C was set up to confirm the performance of the introduced inverter. Simulation and experimental results are shown to validate the theoretical analysis and effectiveness of introduced inverter. The experimental results matched the theoretical analysis and simulation results.

	A Smart Control Method based on Phasor Diagram for Voltage-Type PWM Rectifier with High Power Factor and Constant DC-link Voltage By Shinji KATO	[View] [Download]
Abstract: A smart control method based on the phasor diagram for a voltage-type PWM rectifier is proposed in this paper. The proposed method uses no PI controller in order to produce the high power factor and the constant DC-link voltage. From simulation results, we can realize the constant DC-link voltage of 300\,V, 600\,V, 900\,V or 1000\,V and the high power factor over 0.98.

	A Study on DC-Link-Type Quasi-Switched-Boost Inverters with Improved Voltage Gain By Minh-Khai NGUYEN	[View] [Download]
Abstract: The DC-link type quasi-switched boost inverters (DCL-qSBIs) are known as one of impedance-source inverters with low voltage stress on their additional switch, diode, and capacitor. However, the voltage gain of DCL-qSBIs is still low. This paper presents DCL-qSBIs with a modified PWM control strategy. The modified PWM control strategy based DCL-qSBIs improve voltage gain, reduce the conduction loss, and decrease the voltage stress of devices in the switched-boost network. The operating principle of DCL-qSBIs is presented. The 1 kVA-prototype three-phase DCL-qSBI and quasi-Z-source inverter (qZSI) is built to evaluate the performance of the inverters at output voltage ratio of 1.05 to 1.6. The measured efficiency of DCL-qSBI is 0.5 to 1\% higher than that of the qZSI at all powers and boost levels tested.

	Class-E/?2 6.78 MHz HD-GiT-GaN based Amplifiers for WPT Systems By Martin SCHIESTL	[View] [Download]
Abstract: In this work, the influence of the load variation on the performance and voltage stress of high frequency zero voltage switching Class-E and Class-?2 amplifier with GaN devices in the power range up to 100 W is investigated. With several transient simulations a window of efficient operation for various amounts of loads is found. This proposed procedure can be used for various kinds of amplifiers in order to compare their suitability for different loads. In addition, the individual switch terminal waveforms are checked by their conformity between measurement and simulation. This leads to an improved selection process for the switch to further reduce losses. The converters are driven at a ISM band frequency of 6.78 MHz used in Wireless Power Transfer Systems based on the Air-Fuel standard. The proposed amplifiers exhibit efficiency up to 95\%.

	Comparative Analysis on Gain Feature between CLTC and CDT-LC By Bo CHEN	[View] [Download]
Abstract: A resonant DC-DC converter with dual-transformer structure is proposed. The converter improves the efficiency and gain characteristics. It has the ability to achieve wide range voltage regulation in a narrow frequency range. At the same time, a simplified method of double transformers and its gain characteristics are analyzed in details. Finally, a 2.5 kW prototype is built to verify the theoretical analysis, and the maximum efficiency is 97\%.

	Design and verification of Compact Inductor for Interleaved AC/DC Converter By Gopal MONDAL	[View] [Download]
Abstract: Interleaving concepts with coupled inductors can be utilized for the reduction of passive component size, losses, and material cost. With coupled inductors, not all harmonics are attenuated and additional filter stages may be necessary. The paper presents an inductor designed to reduce both switching harmonics circulating within the coupled inductor as well as higher order harmonics injected into the grid. Analytical equations are derived for both conventional and the proposed inductors to show the benefits and the results are demonstrated with a lab prototype.

	Discussion on Loss Breakdown of 99.6\% Efficiency Two Battery HEECS Inverter By Satoshi NAKAZAKI	[View] [Download]
Abstract: A very high efficiency HEECS topology inverter was proposed at ECCE2018, and after several modifications a very high efficiency 99.6\% is observed at approximately 2.3 kW output. In this paper, the loss breakdown is summarized and the possibility for the higher efficiency is discussed based on the loss analysis.

	Hybrid Alternate-Common-Arm Converter With Director Thyristors--Impact of Commutation Time on the Active-Power Capability By Panagiotis BAKAS	[View] [Download]
Abstract: This paper investigates the impact of the thyristor commutation time on the peak currents and the activ-power capability of the hybrid alternate-common-arm converter (HACC). This converter employs director thyristors for the alternate connection of a common arm in parallel to the main arms. The parallel connection enables current sharing among the arms, which allows the HACC to transfer higher output power without increasing the peak arm current. It is shown that the active-power capability of the HACC is doubled for a certain current-sharing factor, which, however, is altered by the thyristor commutation time. Therefore, the impact of the commutation time on the active-power capability of the HACC is investigated theoretically. Finally, this analysis is verified by simulation results.

	Loss and Thermal Analyses for Modular Multilevel Converters By Waqas ALI	[View] [Download]
Abstract: A modular multilevel converter exhibits large loss and temperature differences within a submodulewhen operated with a power factor close to unity. It has been shown that these temperaturedifferences can be decreased by implementing low loss modulation techniques and circulatingcurrent control, increasing reliability and lifetime.

	Low Frequency Mode Operation for Direct ac-ac Modular Multilevel Converter Systems. A Comparison of M3C and Hex-Y Topology. By Pawel BLASZCZYK	[View] [Download]
Abstract: Modular Multilevel Converters (MMC) are power electronics systems used for energy conversion. Onetopology of MMC is Cascaded MMC characterized by series connection of cells. Each cell canprovide at least two different voltage levels. Resulting voltage in the converter arm is a sum of celloutput voltages.Depending on the application, converters can be divided by number of phases in interconnected systems.One of the applications is 3-phase to 3-phase ac-ac power conversion found e.g. in motor drives, powergeneration or grid frequency changers. In case there is no intermediate DC link between input andoutput, subgroup called direct-MMC can be distinguished. Following family includes Matrix Converter(M3C), Hexverter and Hex-Y.One of the challenging operation points for direct AC-AC MMC is a low frequency mode. In case ofrequired non-zero torque at low speed, module oversizing is necessary. An example applications with flattorque-speed characteristics are rolling / mining applications, hydro power generators or geralesswind generators.In following paper, low frequency mode with non-zero load torque is being analyzed for two of aforementionedtopologies: proposed by author Hex-Y topology and M3C used as a reference (due to identicalnumber of branches). Control algorithm providing given output voltages and currents plus equal branchenergy sharing has been described in detail.Control loop design for Hex-Y has been verified using Hardware in-the-loop simulator.

	Modulation limit of bootstrap power supply circuits: case study of a three level T-type converter By Nicklas CHRISTENSEN	[View] [Download]
Abstract: A bootstrap power supply is used to reduce the number of DC/DC converters needed for supplying the gate drivers. The advantage of a bootstrap is the reduction of size and cost for gate driver circuitry. The disadvantages is a modulation index limit. A modulation index limit can be compensated for, by increasing the DC-link voltage and thereby raising switching losses. It is therefore critical to accurately determine the modulation index limit, to prevent excessive losses, obtain safe operation and to evalu- ate the applicability of a bootstrap. The design rules of a bootstrap currently relies on rules of thumb estimations, generally underestimating the modulation index limit. In this paper a new generic method for calculating the modulation index limit is presented. The method takes on-state resistance, switching states and output current into consideration. The method is validated based on a proposed bootstrap cir- cuit for a three level T-type converter. The proposed circuit achieves equivalent charging states as a half bridge bootstrap.

	New Multilevel Inverter Topology with Reduced Component Count By Ahmed SALEM	[View] [Download]
Abstract: This paper introduces a new topology of modular multilevel inverters, being suitable in medium and high voltage applications. As compared to the existing circuits, the proposed topology has advantages of high `levels/components' ratio, increasing the output voltage levels without increasing the voltage stress across the used switches, structure simplicity, isolation features, and modularity. These merits allow it to fit well in high-reliability medium-power applications, which require fast troubleshooting and maintenance flexibility. Operating principles of the proposed scheme are detailed in low frequency and pulse width modulation. Simulation and experimental results validate the effectiveness of the circuit under different modulation and load conditions. Further, a comparative study between the proposed topology and other existing multilevel topologies was conducted and summarized in this paper.

	Optimized Dual Two-Level Inverter for Safe and Reliable Operation of Machines with Superconductive Stator Windings By Johannes BUEDEL	[View] [Download]
Abstract: This paper aims to present an optimized inverter topology, based on the dual two-level inverter, for feeding an open-end winding electrical machine with superconductive stator windings and a superconductive rotor. In order to achieve a high torque density, the stator windings are built of several superconducting tapes being in parallel. One inverter of the dual two-level inverter is equipped with powerful IGBT semiconductors and supplies the machine with energy. The second inverter is a low voltage MOSFET inverter that monitors the superconductor resistance (quench detection) and balances the current on the parallel superconductive tapes for guaranteeing an optimum operation with respect to the superconductive losses.

	Quasi-Two-Level Operation of a Five-Level Flying-Capacitor Converter By Sidney GIERSCHNER	[View] [Download]
Abstract: This paper deals with the quasi-two-level operation of a five-level Flying-Capacitor converter.The combination of the quasi-two-level operation and multilevel converters enables several opportunities.The series connection of low-voltage devices allows higher switching frequencieseven at high DC-link voltages. The use of intermediate levels decreases the dv/dt of the outputvoltage during the switching transients and improves the voltage spectrum. Furthermore,regarding the flying capacitors, the installed capacitance required can be significantly reduced.The redundant switching states are usually used to balance the capacitor voltages. However,this can be associated with enormous complexity, especially with a high number of levels. Thispaper considers two methods of voltage balancing for the quasi-two-level operation, which dowithout the redundant switching states and are based solely on the adaptation of the dwell timesof the individual intermediate levels. The first considers the flying capacitors separated so thatthe change of the dwell time happens independently. However, this leads to a variable dv/dtof the output voltage. The second method considers all flying capacitors of a phase togetherand assigns the dwell time according to the capacitor voltages. This results in an approximatelyconstant dv/dt of the output voltage.The functionality of the quasi-two-level operation and the two balancing methods are explainedand confirmed by simulation.