EPE Association: EPE 2016 - DS2b: Advanced Power Converter Topologies

EPE 2016 - DS2b: Advanced Power Converter Topologies
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 2016 ECCE Europe - Conference > EPE 2016 - Topic 02: Power Converter Topologies and Design > EPE 2016 - DS2b: Advanced Power Converter Topologies

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   A Multilevel Inverter Fed IM Drive with Dodecagonal Voltage Space Vector Structure using a Single DC Source with Linear Modulation Range Near to Base Speed
By Mathews BOBY [View]
[Download]

Abstract: A fifth and seventh order harmonic elimination scheme for IM drive with a multilevel dodecagonalvoltage space vector structure using a single DC source is proposed in this work. Single DC sourcerequirement makes four quadrant operation of the drive system simpler compared to the multilevel dodecagonal structures presented in literatures before. The space vector structure consists of six concentricdodecagons, combining the advantages of multilevel operation as well as dodecagonal structure. Thetopology consists of a three-level flying capacitor (FC) inverter cascaded with a capacitor fed H-bridge(CHB) inverter. The FC inverter operating at high voltage switches in a quasi-square wave mode whereasthe CHB inverter operating at a lower voltage switches at high frequency to remove the harmonics generatedby the FC inverter. Switching losses are low, both in the FC and CHB inverters. Experiment resultsfor open-loop V/f operation are included in this paper showing the effectiveness of the drive scheme.

   A Novel Six Level Inverter for Single Phase Stand-Alone Photovoltaic System
By Pradyumn CHATURVEDI [View]
[Download]

Abstract: This paper proposes the fundamental-frequency modulated novel six-level inverter topology for singlephasestand-alone photovoltaic (PV) system. It consists of a full-bridge inverter circuit with two pairs ofanti-parallel connected switching devices, four diodes and three independent DC sources (PV modules)to obtain six level output. The theoretical discussion of proposed system is also supported by simulationand laboratory prototype results.

   Balancing of Modular Multilevel Converters with Unbalanced Integration of Energy Storage Devices
By Gerrit HENKE [View]
[Download]

Abstract: In the currently predominant AC-Grid, energy reserves are provided by the inertia of rotating synchronousgenerators. In a potential DC-Grid, there is no such inherent energy reserve and thus additionalenergy storage (ES) is required to ensure grid stability. The Modular Multilevel Converter (MMC) is anemerging technology for HVDC-Grid applications and offers a convenient way of connecting ES to thegrid. Short strings of batteries or supercapacitors can be integrated directly into the MMC submodules,creating an ES enabled MMC, which reduces the susceptibility of the system to an individual ES cellfailure.Since connecting ES to the submodule cells requires additional electrical devices (switches and/or inductors),reducing the number of submodules with integrated ES can significantly reduce the additionalcost for ES integration. In most research conducted on this topic so far, the existence of ES in all MMCmodules is assumed. However, the amount of ES in an ES enabled MMC can be reduced by utilizingcircular currents to achieve energy balance between submodules with and without integrated ES. By inducingcircular currents, energy can be transferred between any phase arms, and phase arms with ES cansupply those without. The focus of this examination is the additional semiconductor load caused by thecircular currents. It is shown that there is only a very small increase in the semiconductor load, whenonly a few arms supply the whole output power.

   Benefits and Challenges of New Semiconductor Solutions in AC-Drives
By Klaus VOGEL [View]
[Download]

Abstract: New standards and requirements for energy efficiency and power loss measurements for variable speed drives are presented. The power losses of typical variable speed drives with rated power of 22 kW are analyzed and alternatives to increase the drives efficiency together with system impact are investigated. An innovative motor drive with silicon carbide (SiC) devices and integrated LC filter is discussed as a future possibility.

   Control of M2C Direct Converter for AC to AC Conversion with Wide Frequency Range
By GOPAL MONDAL [View]
[Download]

Abstract: Modular Multi-level converters are the most discussed topic in the field of HVDC for AC to DC conversions. In thispaper it is shown that modular multi-level converters with series connected H-bridges have the capability to convert3-phase AC to single phase AC. Additionally M2C with full bridge modules has many degrees of freedoms in termsof frequency and voltage levels. In addition, it does not need any passive component for the AC to AC conversionlike in case of resonant converters. The output single phase AC can have a wide range of frequency, independent ofthe 3-phase grid frequency. This ability of M2C makes it suitable for varieties of application. For example in railwayelectrification, the conversion from single phase AC to 3 phase AC to run the three phase motors attached to thewheels. It can be used in solid state grid application for the high frequency isolation without using isolated DC/DCconverters. The control challenges of this type of the Modular Multilevel Converter are presented in this paper.

   Design of a cascaded hybrid multilevel converter for traction application
By Ingmar KIRCHNER [View]
[Download]

Abstract: This paper introduces a efficient design a the grid side inverter for railway applications in cascadedmultilevel hybrid technology. It is shown how to balance the capacitor voltages and how to dimension thecapacitor size for different control strategies. Additionally the calculated power losses for this topologyare determined and compared with two-level converter.

   Efficiency Improvement of a Flyback Converter by Employing a Stepped Air-Gap Transformer
By Panagiotis MANTZANAS [View]
[Download]

Abstract: This paper introduces a flyback converter utilizing a stepped air-gap transformer. By employing such a transformer, the converter efficiency can be noticeably improved in comparison to a conventional flyback converter. Measurements confirm a total loss reduction of up to 6.4 \%.

   Enhanced Power Device Configuration and Operation of a Grid-Connected Active-Neutral-Point-Clamped Inverter for Wind Energy Conversion Systems
By Luis CABALLERO [View]
[Download]

Abstract: The power ratings of wind energy conversion systems (WECS) are increasing considerably due tohigh demand on wind power. Thus, multilevel power converters are becoming an interesting solutionin the largest WECS, especially the three-level neutral-point-clamped (3L-NPC) thanks to its simpleimplementation and proper performance compared to other topologies. However, the main drawbackof the 3L-NPC is that the power losses are unevenly distributed among the switching devices, limitingits output power capability. Current literature focuses on the three-level active neutral-point-clamped(3L-ANPC) as an evolution of the 3L-NPC, enabling a more even power loss distribution. However, inthe 3L-ANPC there are still some devices suffering from both large switching and conduction powerlosses. Thus, this paper proposes new design guidelines for a 3L-ANPC inverter to force that eachdevice mainly withstands either switching or conduction power losses. Then, the most suitable deviceis selected for each position, enabling a significant improvement in power loss distribution, thermalperformance, converter efficiency and output power capability. A 2 MW low-voltage WECS issimulated with an electro-thermal model developed in PLECS, reaching a reduction of around 25\% inpower losses, a reduction of 50\% in maximum junction temperature increase above ambienttemperature, a reduction of 75\% in maximum junction temperature variation, and an increase ofaround 85\% in converter output power rating, compared to the conventional 3L-NPC and the 3L-ANPC.

   Experimental investigation of freewheeling current in indirect matrix converters when abnormal situation
By Kyungmin SUNG [View]
[Download]

Abstract: In this paper, the normally-on type bidirectional switch, in which is comprised of normally-on and normally-off switching devices is proposed for one of a protection method of the Matrix Converter (MC). A diode clamp circuit or auxiliary protection circuits have to keep inductive load current loop in a MC utilized a bidirectional switch when the MC becomes gate block situation under abnormal conditions. We focus that the normally-on type switching devices like SiC-JFET and GaN HFET becomes turn-on state, when zero gate bias voltage. These characteristic of normally-on type is used to replace diode clamp circuit in MC driver system. In this research, the experimentation based on indirect MC for Induction Motor (IM) driver system was carried out. The experimental result of IM driver shows that the proposed bidirectional switch can overcome a generated inductive load current. Under a variety of operation conditions of voltage, frequency, and load torque, the proposed method is investigated and evaluated.

   Extending the State Plane Analysis of Parallel Resonant Converter by Incorporating Several Non-Ideality Sources
By Bekir FINCAN [View]
[Download]

Abstract: This study presents a detailed approach to extend the conventional state plane analysis (SPA) of theparallel resonant converter (PRC) by including some non-ideality sources which might influence theoperation of the circuit. It is experimentally shown that the proposed method improves the SPA of PRCdramatically.

   Multi-Objective Model Predictive Control for Grid-Tied 15-Level Packed U Cells Inverter
By Mohamed TRABELSI [View]
[Download]

Abstract: This paper presents a multi-objective Model Predictive Control (MPC) for grid-tied 4-cell 15-level Packed U Cells (PUC) inverter. This challenging topology is characterized by high power quality with reduced number of components compared to conventional multilevel inverters. Compared to traditional PI controller, MPC is attracting more interest due to its good dynamic response and high accuracy of reference tracking, through the minimization of a flexible user-defined cost function. For the presented PUC topology, the grid current should be jointly controlled with the capacitors' voltages for ensuring proper operation of the inverter, which leads to an additional requirement of pre-charge circuits for the capacitors in case of using PI current controller (or using additional PI controllers). The proposed MPCachieves grid current injection, low current THD, unity PF, while balancing the capacitors' voltages.

   The ZetaBoost: a step-up DC/DC topology derived from the Zeta converter
By Pietro GIANNELLI [View]
[Download]

Abstract: This work investigates a step-up topology derived from the Zeta converter: the ZetaBoost. A ZetaBoost converter design for consumer applications is presented and its steady-state performances are compared to a classical Boost converter with the support of computer simulations and measurements. The results presented include the efficiency and output voltage ripple.

EPE 2016 - DS2b: Advanced Power Converter Topologies
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 2016 ECCE Europe - Conference > EPE 2016 - Topic 02: Power Converter Topologies and Design > EPE 2016 - DS2b: Advanced Power Converter Topologies
	[return to parent folder]

	A Multilevel Inverter Fed IM Drive with Dodecagonal Voltage Space Vector Structure using a Single DC Source with Linear Modulation Range Near to Base Speed By Mathews BOBY	[View] [Download]
Abstract: A fifth and seventh order harmonic elimination scheme for IM drive with a multilevel dodecagonalvoltage space vector structure using a single DC source is proposed in this work. Single DC sourcerequirement makes four quadrant operation of the drive system simpler compared to the multilevel dodecagonal structures presented in literatures before. The space vector structure consists of six concentricdodecagons, combining the advantages of multilevel operation as well as dodecagonal structure. Thetopology consists of a three-level flying capacitor (FC) inverter cascaded with a capacitor fed H-bridge(CHB) inverter. The FC inverter operating at high voltage switches in a quasi-square wave mode whereasthe CHB inverter operating at a lower voltage switches at high frequency to remove the harmonics generatedby the FC inverter. Switching losses are low, both in the FC and CHB inverters. Experiment resultsfor open-loop V/f operation are included in this paper showing the effectiveness of the drive scheme.

	A Novel Six Level Inverter for Single Phase Stand-Alone Photovoltaic System By Pradyumn CHATURVEDI	[View] [Download]
Abstract: This paper proposes the fundamental-frequency modulated novel six-level inverter topology for singlephasestand-alone photovoltaic (PV) system. It consists of a full-bridge inverter circuit with two pairs ofanti-parallel connected switching devices, four diodes and three independent DC sources (PV modules)to obtain six level output. The theoretical discussion of proposed system is also supported by simulationand laboratory prototype results.

	Balancing of Modular Multilevel Converters with Unbalanced Integration of Energy Storage Devices By Gerrit HENKE	[View] [Download]
Abstract: In the currently predominant AC-Grid, energy reserves are provided by the inertia of rotating synchronousgenerators. In a potential DC-Grid, there is no such inherent energy reserve and thus additionalenergy storage (ES) is required to ensure grid stability. The Modular Multilevel Converter (MMC) is anemerging technology for HVDC-Grid applications and offers a convenient way of connecting ES to thegrid. Short strings of batteries or supercapacitors can be integrated directly into the MMC submodules,creating an ES enabled MMC, which reduces the susceptibility of the system to an individual ES cellfailure.Since connecting ES to the submodule cells requires additional electrical devices (switches and/or inductors),reducing the number of submodules with integrated ES can significantly reduce the additionalcost for ES integration. In most research conducted on this topic so far, the existence of ES in all MMCmodules is assumed. However, the amount of ES in an ES enabled MMC can be reduced by utilizingcircular currents to achieve energy balance between submodules with and without integrated ES. By inducingcircular currents, energy can be transferred between any phase arms, and phase arms with ES cansupply those without. The focus of this examination is the additional semiconductor load caused by thecircular currents. It is shown that there is only a very small increase in the semiconductor load, whenonly a few arms supply the whole output power.

	Benefits and Challenges of New Semiconductor Solutions in AC-Drives By Klaus VOGEL	[View] [Download]
Abstract: New standards and requirements for energy efficiency and power loss measurements for variable speed drives are presented. The power losses of typical variable speed drives with rated power of 22 kW are analyzed and alternatives to increase the drives efficiency together with system impact are investigated. An innovative motor drive with silicon carbide (SiC) devices and integrated LC filter is discussed as a future possibility.

	Control of M2C Direct Converter for AC to AC Conversion with Wide Frequency Range By GOPAL MONDAL	[View] [Download]
Abstract: Modular Multi-level converters are the most discussed topic in the field of HVDC for AC to DC conversions. In thispaper it is shown that modular multi-level converters with series connected H-bridges have the capability to convert3-phase AC to single phase AC. Additionally M2C with full bridge modules has many degrees of freedoms in termsof frequency and voltage levels. In addition, it does not need any passive component for the AC to AC conversionlike in case of resonant converters. The output single phase AC can have a wide range of frequency, independent ofthe 3-phase grid frequency. This ability of M2C makes it suitable for varieties of application. For example in railwayelectrification, the conversion from single phase AC to 3 phase AC to run the three phase motors attached to thewheels. It can be used in solid state grid application for the high frequency isolation without using isolated DC/DCconverters. The control challenges of this type of the Modular Multilevel Converter are presented in this paper.

	Design of a cascaded hybrid multilevel converter for traction application By Ingmar KIRCHNER	[View] [Download]
Abstract: This paper introduces a efficient design a the grid side inverter for railway applications in cascadedmultilevel hybrid technology. It is shown how to balance the capacitor voltages and how to dimension thecapacitor size for different control strategies. Additionally the calculated power losses for this topologyare determined and compared with two-level converter.

	Efficiency Improvement of a Flyback Converter by Employing a Stepped Air-Gap Transformer By Panagiotis MANTZANAS	[View] [Download]
Abstract: This paper introduces a flyback converter utilizing a stepped air-gap transformer. By employing such a transformer, the converter efficiency can be noticeably improved in comparison to a conventional flyback converter. Measurements confirm a total loss reduction of up to 6.4 \%.

	Enhanced Power Device Configuration and Operation of a Grid-Connected Active-Neutral-Point-Clamped Inverter for Wind Energy Conversion Systems By Luis CABALLERO	[View] [Download]
Abstract: The power ratings of wind energy conversion systems (WECS) are increasing considerably due tohigh demand on wind power. Thus, multilevel power converters are becoming an interesting solutionin the largest WECS, especially the three-level neutral-point-clamped (3L-NPC) thanks to its simpleimplementation and proper performance compared to other topologies. However, the main drawbackof the 3L-NPC is that the power losses are unevenly distributed among the switching devices, limitingits output power capability. Current literature focuses on the three-level active neutral-point-clamped(3L-ANPC) as an evolution of the 3L-NPC, enabling a more even power loss distribution. However, inthe 3L-ANPC there are still some devices suffering from both large switching and conduction powerlosses. Thus, this paper proposes new design guidelines for a 3L-ANPC inverter to force that eachdevice mainly withstands either switching or conduction power losses. Then, the most suitable deviceis selected for each position, enabling a significant improvement in power loss distribution, thermalperformance, converter efficiency and output power capability. A 2 MW low-voltage WECS issimulated with an electro-thermal model developed in PLECS, reaching a reduction of around 25\% inpower losses, a reduction of 50\% in maximum junction temperature increase above ambienttemperature, a reduction of 75\% in maximum junction temperature variation, and an increase ofaround 85\% in converter output power rating, compared to the conventional 3L-NPC and the 3L-ANPC.

	Experimental investigation of freewheeling current in indirect matrix converters when abnormal situation By Kyungmin SUNG	[View] [Download]
Abstract: In this paper, the normally-on type bidirectional switch, in which is comprised of normally-on and normally-off switching devices is proposed for one of a protection method of the Matrix Converter (MC). A diode clamp circuit or auxiliary protection circuits have to keep inductive load current loop in a MC utilized a bidirectional switch when the MC becomes gate block situation under abnormal conditions. We focus that the normally-on type switching devices like SiC-JFET and GaN HFET becomes turn-on state, when zero gate bias voltage. These characteristic of normally-on type is used to replace diode clamp circuit in MC driver system. In this research, the experimentation based on indirect MC for Induction Motor (IM) driver system was carried out. The experimental result of IM driver shows that the proposed bidirectional switch can overcome a generated inductive load current. Under a variety of operation conditions of voltage, frequency, and load torque, the proposed method is investigated and evaluated.

	Extending the State Plane Analysis of Parallel Resonant Converter by Incorporating Several Non-Ideality Sources By Bekir FINCAN	[View] [Download]
Abstract: This study presents a detailed approach to extend the conventional state plane analysis (SPA) of theparallel resonant converter (PRC) by including some non-ideality sources which might influence theoperation of the circuit. It is experimentally shown that the proposed method improves the SPA of PRCdramatically.

	Multi-Objective Model Predictive Control for Grid-Tied 15-Level Packed U Cells Inverter By Mohamed TRABELSI	[View] [Download]
Abstract: This paper presents a multi-objective Model Predictive Control (MPC) for grid-tied 4-cell 15-level Packed U Cells (PUC) inverter. This challenging topology is characterized by high power quality with reduced number of components compared to conventional multilevel inverters. Compared to traditional PI controller, MPC is attracting more interest due to its good dynamic response and high accuracy of reference tracking, through the minimization of a flexible user-defined cost function. For the presented PUC topology, the grid current should be jointly controlled with the capacitors' voltages for ensuring proper operation of the inverter, which leads to an additional requirement of pre-charge circuits for the capacitors in case of using PI current controller (or using additional PI controllers). The proposed MPCachieves grid current injection, low current THD, unity PF, while balancing the capacitors' voltages.

	The ZetaBoost: a step-up DC/DC topology derived from the Zeta converter By Pietro GIANNELLI	[View] [Download]
Abstract: This work investigates a step-up topology derived from the Zeta converter: the ZetaBoost. A ZetaBoost converter design for consumer applications is presented and its steady-state performances are compared to a classical Boost converter with the support of computer simulations and measurements. The results presented include the efficiency and output voltage ripple.