EPE Association: EPE 2019 - LS1b: Modular Multilevel Converters (MMC)

EPE 2019 - LS1b: Modular Multilevel Converters (MMC)
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 - LS1b: Modular Multilevel Converters (MMC)

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   A New Capacitor Voltage Balancing Method for Trapezoidal Operation of Modular Multilevel DC-DC Converters
By Beeond M. SALEH [View]
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Abstract: In this paper, a new submodule (SM) capacitor voltage balancing algorithm is proposed for the trapezoidal operation of a Modular Multilevel DC-DC converter (MMC-DC-DC) for HVDC/MVDC. Trapezoidal wave-shaping leads to SM switching at fundamental frequency, making the balancing process more challenging. In the proposed method, balancing is achieved by controlling the equivalent duty-cycle of each SM. This control is made possible by the exploitation of the ramps in the trapezoidal voltage waveforms, that allow to impose an uneven power flow in the different SMs. The proposed balancing has been validated in PLECS simulation for a 10MW, 20kV -20kV MMC-DC-DC converter.

   Back-to-Back Modular Multilevel Converter Topology with DC-Link Switches for High-Power Four-Quadrant Variable Speed Motor Drives
By Dianguo XU [View]
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Abstract: This paper presents a new high-power four-quadrant motor drive topology using modular multilevel converters (MMC). By employing thyristors in the DC-link and applying appropriate coordination control, the issue of excessive capacitor voltage ripple at low motor speeds can be solved. Simulation results are provided to show its effectiveness.

   Design Considerations and Comparison of Hybrid Line-Commutated and Cascaded Full-Bridge Converters With Reactive-Power Compensation and Active Filtering Capabil
By Panagiotis BAKAS [View]
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Abstract: This paper compares two hybrid topologies that combine the line-commutated converter (LCC) with cascaded full-bridge (FB) converters. The latter are utilized for compensating the reactive power and filtering the current harmonics of the LCC. The method that was developed for dimensioning these hybrid topologies is presented in detail. This method is utilized for calculating the arm voltage and current waveforms, which are used to estimate other important quantities, such as conduction losses and energy variations. Finally, the studied converters are compared in terms of voltage/current ratings, semiconductor requirements, conduction losses, and energy variations.

   Quasi-Two-Level PWM-Operated Modular Multilevel Converter With Non-Linear Branch Inductors
By Jakub KUCKA [View]
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Abstract: Quasi-two-level PWM operation of modular multilevel converters enables very low module capacitance even at low machine speeds and high torques, while the current distortion is tolerable. In this paper, the application of non-linear inductors together with this operation mode is investigated to further decrease the module capacitances. The requirements for the inductors are analytically derived and the design of the non-linear inductors using a stepped air gap is demonstrated. The feasibility and the advantages of quasi-two-level PWM operation with non-linear inductors are validated using simulations and a laboratoryprototype.

EPE 2019 - LS1b: Modular Multilevel Converters (MMC)
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 - LS1b: Modular Multilevel Converters (MMC)
	[return to parent folder]

	A New Capacitor Voltage Balancing Method for Trapezoidal Operation of Modular Multilevel DC-DC Converters By Beeond M. SALEH	[View] [Download]
Abstract: In this paper, a new submodule (SM) capacitor voltage balancing algorithm is proposed for the trapezoidal operation of a Modular Multilevel DC-DC converter (MMC-DC-DC) for HVDC/MVDC. Trapezoidal wave-shaping leads to SM switching at fundamental frequency, making the balancing process more challenging. In the proposed method, balancing is achieved by controlling the equivalent duty-cycle of each SM. This control is made possible by the exploitation of the ramps in the trapezoidal voltage waveforms, that allow to impose an uneven power flow in the different SMs. The proposed balancing has been validated in PLECS simulation for a 10MW, 20kV -20kV MMC-DC-DC converter.

	Back-to-Back Modular Multilevel Converter Topology with DC-Link Switches for High-Power Four-Quadrant Variable Speed Motor Drives By Dianguo XU	[View] [Download]
Abstract: This paper presents a new high-power four-quadrant motor drive topology using modular multilevel converters (MMC). By employing thyristors in the DC-link and applying appropriate coordination control, the issue of excessive capacitor voltage ripple at low motor speeds can be solved. Simulation results are provided to show its effectiveness.

	Design Considerations and Comparison of Hybrid Line-Commutated and Cascaded Full-Bridge Converters With Reactive-Power Compensation and Active Filtering Capabil By Panagiotis BAKAS	[View] [Download]
Abstract: This paper compares two hybrid topologies that combine the line-commutated converter (LCC) with cascaded full-bridge (FB) converters. The latter are utilized for compensating the reactive power and filtering the current harmonics of the LCC. The method that was developed for dimensioning these hybrid topologies is presented in detail. This method is utilized for calculating the arm voltage and current waveforms, which are used to estimate other important quantities, such as conduction losses and energy variations. Finally, the studied converters are compared in terms of voltage/current ratings, semiconductor requirements, conduction losses, and energy variations.

	Quasi-Two-Level PWM-Operated Modular Multilevel Converter With Non-Linear Branch Inductors By Jakub KUCKA	[View] [Download]
Abstract: Quasi-two-level PWM operation of modular multilevel converters enables very low module capacitance even at low machine speeds and high torques, while the current distortion is tolerable. In this paper, the application of non-linear inductors together with this operation mode is investigated to further decrease the module capacitances. The requirements for the inductors are analytically derived and the design of the non-linear inductors using a stepped air gap is demonstrated. The feasibility and the advantages of quasi-two-level PWM operation with non-linear inductors are validated using simulations and a laboratoryprototype.