EPE Association: EPE 2022 - DS2g: Standard and Advanced Modulation Techniques

EPE 2022 - DS2g: Standard and Advanced Modulation Techniques
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 2022 ECCE Europe - Conference > EPE 2022 - Topic 04: Electrical Machines and Drive Systems > EPE 2022 - DS2g: Standard and Advanced Modulation Techniques

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   Comparative evaluation of the 5-phase Vienna and the 5-phase PWM rectifiers under DC voltage control
By Abdoulaye DIENG [View]
[Download]

Abstract: Here a comparative evaluation of the 5-phase Vienna and the 5-phase PWM rectifiers is done. A double closed control loops strategy with an internal current loop and an external voltage loop is investigated. An itemized analysis is performed then the simulations and experimental results are done

   Efficiency Improvement of Single-Stage AC-DC LLC Converter Using a Line Cycle Synchronous Rectifier (SR) Driving Strategy
By Mojtaba FOROUZESH [View]
[Download]

Abstract: Synchronous rectification that is being widely used in high-power Inductor-Inductor-Capacitor (LLC) DC-DC converters to improve efficiency can be challenging in single-stage AC-DC LLC converters with high output voltage levels (i.e., sup.100V) where synchronous driving ICs cannot be used. In this paper, a simple line cycle SR driving strategy with direct MCU control is proposed for single-stage AC-DC LLC converters. The principles of operation and methodology behind the proposed line cycle SR driving strategy are discussed. Simulation and experimental results validated the performance of the proposed SR driving strategy for a 250 V to 400 V output voltage range AC-DC LLC converter. A full-load efficiency of 98.1 \% was achieved for the 250 V output voltage condition and a full-load efficiency of 97.3 \% was achieved for the 400 V output voltage condition. Compared with a fixed ON time method, around 0.5 \%, and 0.8 \% efficiency improvements were observed in 250 V and 400 V output voltage conditions, respectively. In addition, it is observed that the proposed simple SR driving method obtains the same efficiency levels as more complex adaptive SR driving approaches.

   Influence of Carrier-Based PWM Techniques on the Common-Mode Voltage and Common-Mode Current of Six-Phase Full-Bridge Inverter
By Juris ARROZY [View]
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Abstract: This paper compares several carrier-based PWM techniques to see their impact on the common-mode voltage (CMV) and common-mode current (CMC) of a six-phase full-bridge inverters. Fast Fourier Transform (FFT) analysis displays the dominant harmonics spectrum of each carrier-based PWM technique. The influence of dead-time on the CMV and CMC is also addressed. Simulation and experimental results are included.

   Optimized Control Scheme to Achieve ZVS for the Complete Pre-Charging Phase of Supercapacitors with a 500 kHz SiC- and GaN-Based Dual Active Bridge
By Patrick LENZEN [View]
[Download]

Abstract: Large energy storage systems are used in many applications. If they are not in operation continuously, they will discharge themselves. To restart the operation, the supercapacitors should be pre-charged again to reach the nominal voltage range. Mostly, the capacitors are connected to a source via a DC/DC converter. For a fast reaction on load transients, fast-switching DC/DC converters are needed. Due to the high switching frequencies, soft switching is essential to keep the losses low. This is important for the normal operation but also for the pre-charging phase because pre-charging takes up to several minutes for large capacities. This work presents a zero-voltage switching (ZVS) analysis and extended-phase shift (EPS) modulation to reach ZVS switching for all semiconductors of the DC/DC converter during the complete pre-charge procedure. The analysis is done with a capacitance time-domain-based model and experimentally validated on a prototype.

   Optimized Pulse Pattern with Half-wave Symmetry for 5-Level Converter
By Jonas WEIRES [View]
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Abstract: In this paper, an Optimized Pulse Pattern is developed for a generic 5-Level Voltage Source Converter.The optimization process minimizes the current total harmonic distortion, while switching at the fundamental frequency. By relaxing the constraints to a half-period symmetry, a superior performance isobtained in comparison with existing solutions.

   PWM-Based Optimization-Less Active Voltage-Balancing Control of 7-Level Active Neutral-Point-Clamped Flying-Capacitor Inverters
By Vahid DARGAHI [View]
[Download]

Abstract: This paper introduces a new pulse-width-modulation (PWM) -based control technique for 7-levelactive neutral-point-clamped (A-NPC) flying-capacitor (FC) inverters. It regulates the inverter'soutput voltage and current, and balances the FCs at their target values. It is realized on basis ofactive control approach which is achieved using instantaneous measurements taken from inverter,and then interpreted into the logical quantities. Contrary to the space-vector modulation (SVM)and model predictive control (MPC), the proposed solution is deemed a direct approach whichexcludes the cost functions and its time and software-consuming optimization process to generatethe switching states. It utilizes the measured values of FC voltages and load current to derivelogical variables and equations that directly determine the inverter's switching states accordingto the reference voltage-levels. As an advantage, any commonly used modulators such as phase-shifted-carrier (PSC) or phase-disposition (PD) strategy could be readily embedded into controlunit to generate the inverter's reference voltage-levels. The experimental results are provided tovalidate the suggested active balancing technique, its effectiveness and fast execution-time.

   Single-phase, Five-level Inverter with SPWM-Based Neutral Point Voltage Balancing Scheme
By Dmytro KONDRATENKO [View]
[Download]

Abstract: Multilevel inverter topologies provide several advantages over two-level inverter configuration. These benefits are the reason for the growing interest in multilevel topologies among research society. One of the most popular topological concepts (diode and active switch clamping) requires neutral-point potential balancing due to series-connected capacitor banks across the input dc link in such derived inverter configurations. This paper presents a Sinusoidal PWM (SPWM) scheme that ensures balanced and reduced input capacitor voltages' variations in single-phase T-type inverter. Comparison analyses with existing carrier-based pulse-width modulation methods are provided. Simulation results are provided which showcase the effectiveness of the control approach. Experimental validation of these results was provided with a five-level single-phase T-type VSI; that supplies single-phase RL load.

   Three-Phase ZVS Inverter with Variable and Fixed Frequency Operation based on GaN Semiconductors
By Benedikt KOHLHEPP [View]
[Download]

Abstract: As high efficiency is on everyone's lips, this paper studies an inverter using a ZVS modulation schemepromising high efficiency. It uses triangular current mode (TCM) to minimize the ripple while maintaining ZVS. In order to fulfill the required power density, high switching frequencies should be applied. Current threshold detection circuits in combination with this modulation scheme turn the inverter's legs into current sources. Since all phases of the inverter are tied together at the load's star point, there might be issues, if slight current threshold errors exist within the inverter. In order to demonstrate that the modulation scheme can handle situations with and without connection of the load's neutral point to the DC-link midpoint, both configurations are studied in a practical setup. The practical test setup gives satisfactory results with respect to the quality of the output waveforms using the THD of the currents.

EPE 2022 - DS2g: Standard and Advanced Modulation Techniques
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 2022 ECCE Europe - Conference > EPE 2022 - Topic 04: Electrical Machines and Drive Systems > EPE 2022 - DS2g: Standard and Advanced Modulation Techniques
	[return to parent folder]

	Comparative evaluation of the 5-phase Vienna and the 5-phase PWM rectifiers under DC voltage control By Abdoulaye DIENG	[View] [Download]
Abstract: Here a comparative evaluation of the 5-phase Vienna and the 5-phase PWM rectifiers is done. A double closed control loops strategy with an internal current loop and an external voltage loop is investigated. An itemized analysis is performed then the simulations and experimental results are done

	Efficiency Improvement of Single-Stage AC-DC LLC Converter Using a Line Cycle Synchronous Rectifier (SR) Driving Strategy By Mojtaba FOROUZESH	[View] [Download]
Abstract: Synchronous rectification that is being widely used in high-power Inductor-Inductor-Capacitor (LLC) DC-DC converters to improve efficiency can be challenging in single-stage AC-DC LLC converters with high output voltage levels (i.e., sup.100V) where synchronous driving ICs cannot be used. In this paper, a simple line cycle SR driving strategy with direct MCU control is proposed for single-stage AC-DC LLC converters. The principles of operation and methodology behind the proposed line cycle SR driving strategy are discussed. Simulation and experimental results validated the performance of the proposed SR driving strategy for a 250 V to 400 V output voltage range AC-DC LLC converter. A full-load efficiency of 98.1 \% was achieved for the 250 V output voltage condition and a full-load efficiency of 97.3 \% was achieved for the 400 V output voltage condition. Compared with a fixed ON time method, around 0.5 \%, and 0.8 \% efficiency improvements were observed in 250 V and 400 V output voltage conditions, respectively. In addition, it is observed that the proposed simple SR driving method obtains the same efficiency levels as more complex adaptive SR driving approaches.

	Influence of Carrier-Based PWM Techniques on the Common-Mode Voltage and Common-Mode Current of Six-Phase Full-Bridge Inverter By Juris ARROZY	[View] [Download]
Abstract: This paper compares several carrier-based PWM techniques to see their impact on the common-mode voltage (CMV) and common-mode current (CMC) of a six-phase full-bridge inverters. Fast Fourier Transform (FFT) analysis displays the dominant harmonics spectrum of each carrier-based PWM technique. The influence of dead-time on the CMV and CMC is also addressed. Simulation and experimental results are included.

	Optimized Control Scheme to Achieve ZVS for the Complete Pre-Charging Phase of Supercapacitors with a 500 kHz SiC- and GaN-Based Dual Active Bridge By Patrick LENZEN	[View] [Download]
Abstract: Large energy storage systems are used in many applications. If they are not in operation continuously, they will discharge themselves. To restart the operation, the supercapacitors should be pre-charged again to reach the nominal voltage range. Mostly, the capacitors are connected to a source via a DC/DC converter. For a fast reaction on load transients, fast-switching DC/DC converters are needed. Due to the high switching frequencies, soft switching is essential to keep the losses low. This is important for the normal operation but also for the pre-charging phase because pre-charging takes up to several minutes for large capacities. This work presents a zero-voltage switching (ZVS) analysis and extended-phase shift (EPS) modulation to reach ZVS switching for all semiconductors of the DC/DC converter during the complete pre-charge procedure. The analysis is done with a capacitance time-domain-based model and experimentally validated on a prototype.

	Optimized Pulse Pattern with Half-wave Symmetry for 5-Level Converter By Jonas WEIRES	[View] [Download]
Abstract: In this paper, an Optimized Pulse Pattern is developed for a generic 5-Level Voltage Source Converter.The optimization process minimizes the current total harmonic distortion, while switching at the fundamental frequency. By relaxing the constraints to a half-period symmetry, a superior performance isobtained in comparison with existing solutions.

	PWM-Based Optimization-Less Active Voltage-Balancing Control of 7-Level Active Neutral-Point-Clamped Flying-Capacitor Inverters By Vahid DARGAHI	[View] [Download]
Abstract: This paper introduces a new pulse-width-modulation (PWM) -based control technique for 7-levelactive neutral-point-clamped (A-NPC) flying-capacitor (FC) inverters. It regulates the inverter'soutput voltage and current, and balances the FCs at their target values. It is realized on basis ofactive control approach which is achieved using instantaneous measurements taken from inverter,and then interpreted into the logical quantities. Contrary to the space-vector modulation (SVM)and model predictive control (MPC), the proposed solution is deemed a direct approach whichexcludes the cost functions and its time and software-consuming optimization process to generatethe switching states. It utilizes the measured values of FC voltages and load current to derivelogical variables and equations that directly determine the inverter's switching states accordingto the reference voltage-levels. As an advantage, any commonly used modulators such as phase-shifted-carrier (PSC) or phase-disposition (PD) strategy could be readily embedded into controlunit to generate the inverter's reference voltage-levels. The experimental results are provided tovalidate the suggested active balancing technique, its effectiveness and fast execution-time.

	Single-phase, Five-level Inverter with SPWM-Based Neutral Point Voltage Balancing Scheme By Dmytro KONDRATENKO	[View] [Download]
Abstract: Multilevel inverter topologies provide several advantages over two-level inverter configuration. These benefits are the reason for the growing interest in multilevel topologies among research society. One of the most popular topological concepts (diode and active switch clamping) requires neutral-point potential balancing due to series-connected capacitor banks across the input dc link in such derived inverter configurations. This paper presents a Sinusoidal PWM (SPWM) scheme that ensures balanced and reduced input capacitor voltages' variations in single-phase T-type inverter. Comparison analyses with existing carrier-based pulse-width modulation methods are provided. Simulation results are provided which showcase the effectiveness of the control approach. Experimental validation of these results was provided with a five-level single-phase T-type VSI; that supplies single-phase RL load.

	Three-Phase ZVS Inverter with Variable and Fixed Frequency Operation based on GaN Semiconductors By Benedikt KOHLHEPP	[View] [Download]
Abstract: As high efficiency is on everyone's lips, this paper studies an inverter using a ZVS modulation schemepromising high efficiency. It uses triangular current mode (TCM) to minimize the ripple while maintaining ZVS. In order to fulfill the required power density, high switching frequencies should be applied. Current threshold detection circuits in combination with this modulation scheme turn the inverter's legs into current sources. Since all phases of the inverter are tied together at the load's star point, there might be issues, if slight current threshold errors exist within the inverter. In order to demonstrate that the modulation scheme can handle situations with and without connection of the load's neutral point to the DC-link midpoint, both configurations are studied in a practical setup. The practical test setup gives satisfactory results with respect to the quality of the output waveforms using the THD of the currents.