| 1. |
- Wang, Xiaoyu, et al.
(författare)
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Guest Editorial: Modeling and Simulation Methods for Analysis and Design of Advanced Energy Conversion Systems
- 2020
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Ingår i: IEEE Transactions on Energy Conversion. - 1558-0059 .- 0885-8969. ; 35:1, s. 309-311
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- The papers in this special section examine modeling and simulation methods for the analysis and design of advanced energy conversion systems. Energy conversion lies aEnergyveral fronts including materials, conversion methods, power electronics, and controls have created new opportunities for efficient energy conversion from both the conventional and new sources of energy. Our urgent need to solve many critical problems with regards to the sustainability and security of our energy system as well as the ever-increasing environmental challenges facing humanity have further spurred unprecedented opportunities for creation of innovative solutions to address these challenges.
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| 2. |
- Duan, Jinpei, et al.
(författare)
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Dual-Circulant Modulation for Modular Multilevel DC/DC Converters With Inherent Balance Capability
- 2023
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Ingår i: IEEE transactions on power electronics. - : Institute of Electrical and Electronics Engineers (IEEE). - 0885-8993 .- 1941-0107. ; 38:7, s. 7958-7963
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Tidskriftsartikel (refereegranskat)abstract
- Modular multilevel dc/dc converters (MMDC) have emerged recently for medium-voltage dc applications. Under single-circulant modulation, the submodule (SM) capacitor voltages in MMDC are found to be evenly divided only at some specific modulation coefficients. To obtain the inherent balance capability under all modulation coefficients and expand the application range of circulant modulation, a simple dual-circulant modulation is proposed in this letter. On the basis of single-circulant modulation, the self-balancing of the SM capacitor voltages is realized by using the additional switching patterns generated by a simple circulant permutation method. The theoretical analysis of the proposed method is presented, and the inherent balance capability of MMDC under the dual-circulant modulation method is verified by experiments.
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| 3. |
- Liao, Yicheng, et al.
(författare)
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Frequency-Domain Participation Analysis for Electronic Power Systems
- 2022
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Ingår i: IEEE transactions on power electronics. - : Institute of Electrical and Electronics Engineers (IEEE). - 0885-8993 .- 1941-0107. ; 37:3, s. 2531-2537
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Tidskriftsartikel (refereegranskat)abstract
- This letter proposes a frequency-domain participation analysis approach to identifying the root cause of small-signal instability for electronic power systems. Differing from the participation analysis based on state-space analysis, the proposed approach is implemented based on impedance models, which is, thus, readily applicable for large-scale systems only with black-box models. The theoretical analysis is finally verified by the simulations and experiments.
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| 4. |
- Ojo, Olorunfemi, et al.
(författare)
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Welcome From: Technical Program Chairs
- 2023
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Ingår i: 2023 IEEE Energy Conversion Congress and Exposition, ECCE 2023. - : Institute of Electrical and Electronics Engineers (IEEE).
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Konferensbidrag (refereegranskat)
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| 5. |
- Wang, Xinshuo, et al.
(författare)
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Transient Overvoltage Analysis of Grid-Following VSCs during Fault Recovery
- 2023
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Ingår i: ICPE 2023-ECCE Asia. - : Institute of Electrical and Electronics Engineers (IEEE). ; , s. 2404-2409
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Konferensbidrag (refereegranskat)abstract
- Current grid code has explicit requirement on the fault current injection profile of grid-following voltage-source converters (GFL-VSCs), i.e., the output reactive current of GFL-VSC needs to be proportional to voltage- magnitude deviation at the point of connection (PoC) until its current limitation is reached. This article points out that such way of injecting the fault current may result in transient overvoltage (TOV) at the PoC during fault recovery, and the rate of change of current reference of GFL-VSC is critical to the duration of TOV. Moreover, a method for estimating the maximum magnitude of TOV is presented, which provides an intuitive insight for the TOV phenomenon.
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| 6. |
- Wang, Zhihao, et al.
(författare)
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Current Reference Control Scheme of Voltage Source Converters to Ensure the Existence of Stable Equilibrium Points During Grid Fault
- 2023
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Ingår i: IEEE transactions on power electronics. - : Institute of Electrical and Electronics Engineers (IEEE). - 0885-8993 .- 1941-0107. ; 38:9, s. 10750-10765
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Tidskriftsartikel (refereegranskat)abstract
- Maintaining synchronization with the grid during fault ride-through (FRT) is essential for grid-connected voltage source converters (VSCs). However, improper current references can lead to a loss of synchronization during FRT due to the nonexistence of stable equilibrium points (SEPs). While the mechanism of SEPs has been explained, the development of control schemes ensuring their existence remains challenging due to the difficulty of obtaining real-time grid parameters during FRT. To address this issue, this article proposes a novel current reference control scheme that only requires prefault grid parameters. By analyzing the changes in grid parameters caused by faults and characterizing the correspondence between the during-fault and prefault grid parameters, a voltage-dependent current reference control scheme is proposed. Since no real-time grid parameter estimation is needed during FRT, the proposed control scheme is practical and easy to implement. Simulation studies using DIgSILENT PowerFactory demonstrate that the proposed control scheme enables the VSC to maintain synchronization with the grid under the conditions of short-circuit ratio equaling 1.3 and grid voltage dropping to 0.1 p.u. Moreover, experiments further verify the effectiveness and feasibility of the proposed control scheme.
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| 7. |
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| 8. |
- Zhan, Changjiang, et al.
(författare)
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An Overview of Stability Studies of Grid-forming Voltage Source Converters
- 2023
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Ingår i: Zhongguo Dianji Gongcheng Xuebao/Proceedings of the Chinese Society of Electrical Engineering. - : Chinese Society for Electrical Engineering. - 0258-8013. ; 43:6, s. 2339-2358
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Tidskriftsartikel (refereegranskat)abstract
- Unlike grid-following converters, the grid-forming converter is operated as a synchronous voltage source, which can effectively improve the stability of power-electronics-dominated power systems, and hence, has attracted much research attention in recent years. As a basis of the large-scale implementation of grid-forming converters, there should be an in-depth understanding of its stability under different grid strengths as well as different grid disturbances. This article performs a comprehensive overview of the stability studies of grid-forming converters from the perspective of existence of equilibrium points, small-signal stability, and transient stability. On top of this, stabilization control solutions of grid-forming converters are also summarized. In the end, perspectives on the prospects and challenges of stability analysis of grid-forming converters are shared.
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| 9. |
- Bessegato, Luca, 1989-
(författare)
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Modeling of Modular Multilevel Converters for Stability Analysis
- 2019
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Modular multilevel converters (MMCs) have recently become the state-of-the-art solution for various grid-connected applications, such as high-voltage direct current (HVDC) systems and flexible alternating current transmission systems (FACTS). Modularity, scalability, low power losses, and low harmonic distortion are the outstanding properties that make MMCs a key technology for a sustainable future. The main objective of this thesis is the modeling of grid-connected MMCs for stability analysis. The stability of the interconnected system, formed by the converter and the ac grid, can be assessed by analyzing the converter ac-side admittance in relation to the grid impedance. Therefore, a method for the calculation of the ac-side admittance of MMCs is developed. This method overcomes the nonlinearities of the converter dynamics and it can be easily adapted to different applications. Moreover, the effects of different control schemes on the MMC ac-side admittance are studied, showing how the converter admittance can be reshaped. This is a useful tool for system design, because it shows how control parameters can be selected to avoid undesired grid-converter interactions. This thesis also studies ac/ac MMCs for railway power supplies, which are used in countries with a low-frequency railway grid, such as Germany (16.7 Hz) and Sweden (16 2/3 Hz). A hierarchical control scheme for these converters is devised and evaluated, considering the requirements and the operating conditions specific to this application. Furthermore, admittance models of the ac/ac MMC are developed, showing how the suggested hierarchical control scheme affects the three-phase and the single-phase side admittances of the converter. For computing the insertion indices, an open-loop scheme with sum capacitor voltage estimation is applied to the ac/ac MMC. Lyapunov stability theory is used to prove the asymptotic stability of the converter operated with the proposed control method. This specific open-loop scheme is also adapted to a modular multilevel matrix converter, which performs three-to-three phase direct conversion. Finally, this thesis presents the design of a down-scaled MMC prototype for experimental verification, rated at 10 kW with 30 full-bridge submodules. The hardware and the software are designed to be easily reconfigurable, which makes the converter suitable for different research projects focused on MMCs. Experiments on this down-scaled MMC are used to support and validate the key results presented throughout the thesis.
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| 10. |
- Bhadoria, Shubhangi, et al.
(författare)
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Enablers for Overcurrent Capability of Silicon-Carbide-Based Power Converters : An Overview
- 2023
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Ingår i: IEEE transactions on power electronics. - : Institute of Electrical and Electronics Engineers Inc.. - 0885-8993 .- 1941-0107. ; 38:3, s. 3569-3589
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Tidskriftsartikel (refereegranskat)abstract
- With the increase in penetration of power electronic converters in the power systems, a demand for overcurrent/ overloading capability has risen for the fault clearance duration. This article gives an overview of the limiting factors and the recent technologies for the overcurrent performance of SiC power modules in power electronics converters. It presents the limitations produced at the power module level by packaging materials, which include semiconductor chips, substrates, metallization, bonding techniques, die attach, and encapsulation materials. Specifically, technologies for overcurrent related temperatures in excess of 200°C are discussed. This article also discusses potential technologies, which have been proven or may be potential candidates for improving the safe operating area. The discussed technologies are use of phase-change materials below the semiconductor chip, Peltier elements, new layouts of the power modules, control and modulation techniques for converters. Special attention has been given to an overview of various potential phase-change materials, which can be considered for high-temperature operations.
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