Pub Date : 2024-06-21DOI: 10.1109/OJPEL.2024.3417177
Pan Sun;Leyu Wang;Yan Liang;Xusheng Wu;Qijun Deng
To meet the low-voltage and high-power demand of fast charging of electric vehicles, an ISOP multi-channel inductive power transfer (IPT) system based on LCC-S compensation network is analyzed in this paper. Firstly, the system's improvement of transmission capability is analyzed without considering the cross-coupling. After that, to clarify the cross-coupling impression, the equivalent impedance formula for the inverter output terminals of each channel is calculated. Then, combined with the harmonic characteristics of high order topology, the zero voltage switching (ZVS) condition of each channel is analyzed. Found out that the cross-coupling may lead to a decrease in the instantaneous current value when the inverter is turned on, thereby increasing the risk of losing the ZVS operating state. To eliminate the influence of cross-coupling, a parameter design method is proposed without additional devices and control. Finally, a 3-channel ISOP-IPT system prototype is built. The system achieves an energy transmission of 17.06 kW with an efficiency of 93.22%. Compared with single-channel systems, the power capacity is increased while keeping the input current level unchanged. After compensation, the system achieves equivalent decoupling in the case of cross-coupling, each channel works independently and maintains the input voltage balance.
{"title":"Analysis and Cross-Coupling Elimination of Input-Series Output-Parallel (ISOP) Multi-Channel IPT System","authors":"Pan Sun;Leyu Wang;Yan Liang;Xusheng Wu;Qijun Deng","doi":"10.1109/OJPEL.2024.3417177","DOIUrl":"10.1109/OJPEL.2024.3417177","url":null,"abstract":"To meet the low-voltage and high-power demand of fast charging of electric vehicles, an ISOP multi-channel inductive power transfer (IPT) system based on LCC-S compensation network is analyzed in this paper. Firstly, the system's improvement of transmission capability is analyzed without considering the cross-coupling. After that, to clarify the cross-coupling impression, the equivalent impedance formula for the inverter output terminals of each channel is calculated. Then, combined with the harmonic characteristics of high order topology, the zero voltage switching (ZVS) condition of each channel is analyzed. Found out that the cross-coupling may lead to a decrease in the instantaneous current value when the inverter is turned on, thereby increasing the risk of losing the ZVS operating state. To eliminate the influence of cross-coupling, a parameter design method is proposed without additional devices and control. Finally, a 3-channel ISOP-IPT system prototype is built. The system achieves an energy transmission of 17.06 kW with an efficiency of 93.22%. Compared with single-channel systems, the power capacity is increased while keeping the input current level unchanged. After compensation, the system achieves equivalent decoupling in the case of cross-coupling, each channel works independently and maintains the input voltage balance.","PeriodicalId":93182,"journal":{"name":"IEEE open journal of power electronics","volume":null,"pages":null},"PeriodicalIF":5.0,"publicationDate":"2024-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10568327","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141510971","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-06-20DOI: 10.1109/OJPEL.2024.3417017
Gianluca Roberts;Aleksandar Prodić
This article presents three modulation improvements for the series-capacitor buck (SCB) converter and its topological derivatives. The first consists of various phase activation sequences (PHACTSs) which raise the maximum input-to-output voltage conversion ratio of an N -inductor, N -phase SCB converter beyond the traditional limit of 1/ N 2 , without incurring any additional voltage stress to the switches. Phase counts up to 16 are analyzed with conversion ratios increasing by a factor of up to 7. Due to the inherent link between the converter's maximum attainable output voltage and maximum output current slew rate, these PHACTSs offer a significant improvement to the load-voltage transient response. Utilizing the flying capacitors that link adjacent inductors, a second modulation technique is introduced that effectively increases the digital pulse-width-modulator's (DPWM) output-voltage resolution, by a factor of N , by employing a novel method of minimum duty increments (MDIs). Despite the commonly-held assumption of automatic steady-state inductor-current-balancing present in an N -inductor SCB, large-signal modelling reveals that slight current imbalances inevitably arise, even in lossless configurations, with three or more output inductors. After elucidating its origin, this article introduces a third modulation technique that can reduce these inductor current imbalances through a particular implementation of MDI. A discrete prototype of an 11-inductor, 48 V-to-1.0 V, 275 A-load, SCB converter was fabricated to experimentally demonstrate and validate the simulated results of the increase in both the output voltage ceiling and DPWM resolution, as well as to evaluate the MDI-DPWM output-voltage linearity. Finally, the maintenance of both inductor current balancing and low switch-voltage-stress is experimentally substantiated when using MDI.
本文介绍了串联电容降压（SCB）转换器及其拓扑衍生物的三种调制改进方法。第一种改进包括各种相位激活序列 (PHACTS)，可将 N 电感、N 相 SCB 转换器的最大输入输出电压转换率提高到传统的 1/N2 以上，而不会对开关造成任何额外的电压压力。分析的相数多达 16 相，转换率最多可提高 7 倍。由于转换器的最大输出电压和最大输出电流回转率之间存在固有联系，这些 PHACTS 可显著改善负载电压瞬态响应。利用连接相邻电感器的飞行电容器，引入了第二种调制技术，通过采用新颖的最小占空比增量 (MDI) 方法，有效地将数字脉宽调制器 (DPWM) 的输出电压分辨率提高了 N 倍。尽管人们普遍认为 N 个电感器的 SCB 会自动实现稳态电感器电流平衡，但大信号建模显示，即使在无损耗配置中，在有三个或更多输出电感器的情况下，也不可避免地会出现轻微的电流不平衡。本文在阐明其起源后，介绍了第三种调制技术，该技术可通过 MDI 的特定实施来减少这些电感器电流不平衡现象。本文制作了一个 11 个电感器、48 V 至 1.0 V、275 A 负载、SCB 转换器的离散原型，以实验证明和验证输出电压上限和 DPWM 分辨率提高的模拟结果，并评估 MDI-DPWM 输出电压线性度。最后，实验证实了使用 MDI 时电感器电流平衡和低开关电压应力的维持。
{"title":"Modulation Improvements for High-Phase-Count Series-Capacitor Buck Converters","authors":"Gianluca Roberts;Aleksandar Prodić","doi":"10.1109/OJPEL.2024.3417017","DOIUrl":"10.1109/OJPEL.2024.3417017","url":null,"abstract":"This article presents three modulation improvements for the series-capacitor buck (SCB) converter and its topological derivatives. The first consists of various phase activation sequences (PHACTSs) which raise the maximum input-to-output voltage conversion ratio of an \u0000<italic>N</i>\u0000-inductor, \u0000<italic>N</i>\u0000-phase SCB converter beyond the traditional limit of 1/\u0000<italic>N</i>\u0000<sup>2</sup>\u0000, without incurring any additional voltage stress to the switches. Phase counts up to 16 are analyzed with conversion ratios increasing by a factor of up to 7. Due to the inherent link between the converter's maximum attainable output voltage and maximum output current slew rate, these PHACTSs offer a significant improvement to the load-voltage transient response. Utilizing the flying capacitors that link adjacent inductors, a second modulation technique is introduced that effectively increases the digital pulse-width-modulator's (DPWM) output-voltage resolution, by a factor of \u0000<italic>N</i>\u0000, by employing a novel method of minimum duty increments (MDIs). Despite the commonly-held assumption of automatic steady-state inductor-current-balancing present in an \u0000<italic>N</i>\u0000-inductor SCB, large-signal modelling reveals that slight current imbalances inevitably arise, even in lossless configurations, with three or more output inductors. After elucidating its origin, this article introduces a third modulation technique that can reduce these inductor current imbalances through a particular implementation of MDI. A discrete prototype of an 11-inductor, 48 V-to-1.0 V, 275 A-load, SCB converter was fabricated to experimentally demonstrate and validate the simulated results of the increase in both the output voltage ceiling and DPWM resolution, as well as to evaluate the MDI-DPWM output-voltage linearity. Finally, the maintenance of both inductor current balancing and low switch-voltage-stress is experimentally substantiated when using MDI.","PeriodicalId":93182,"journal":{"name":"IEEE open journal of power electronics","volume":null,"pages":null},"PeriodicalIF":5.0,"publicationDate":"2024-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10565994","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141510973","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-06-20DOI: 10.1109/OJPEL.2024.3416339
Andrea Lauri;Tommaso Caldognetto;Ruggero Carli;Davide Biadene;Paolo Mattavelli
Electronic power converters are extensively applied in microgrids to interface distributed energy resources to the grid. Besides the primary active-power control, electronic converters support increasingly advanced and flexible control capabilities. While the former is typically bound to local needs (e.g., maximum power extraction from renewables), additional degrees of freedom can be exploited to support microgrid operation. This article proposes a control algorithm that allows the optimal provision of reactive power, negative-sequence, and zero-sequence currents by distributed converters. The resulting operation shows enhanced power quality at the point of common coupling (PCC) and limited conversion losses, which are taken into account in the optimization algorithm. Three modes of operation are discussed, that is, i ) power loss minimization; ii ) balanced currents at the PCC; iii ) zero reactive power flow at the PCC. An algorithm based on the primal-dual method is proposed to solve the optimization problem. Results based on experimental measurements are discussed to prove the effectiveness of the proposal.
{"title":"Ancillary Service Provision via Primal-Dual Based Coordination of Distributed Power Electronic Converters in Three-Phase Microgrids","authors":"Andrea Lauri;Tommaso Caldognetto;Ruggero Carli;Davide Biadene;Paolo Mattavelli","doi":"10.1109/OJPEL.2024.3416339","DOIUrl":"https://doi.org/10.1109/OJPEL.2024.3416339","url":null,"abstract":"Electronic power converters are extensively applied in microgrids to interface distributed energy resources to the grid. Besides the primary active-power control, electronic converters support increasingly advanced and flexible control capabilities. While the former is typically bound to local needs (e.g., maximum power extraction from renewables), additional degrees of freedom can be exploited to support microgrid operation. This article proposes a control algorithm that allows the optimal provision of reactive power, negative-sequence, and zero-sequence currents by distributed converters. The resulting operation shows enhanced power quality at the point of common coupling (PCC) and limited conversion losses, which are taken into account in the optimization algorithm. Three modes of operation are discussed, that is, \u0000<italic>i</i>\u0000) power loss minimization; \u0000<italic>ii</i>\u0000) balanced currents at the PCC; \u0000<italic>iii</i>\u0000) zero reactive power flow at the PCC. An algorithm based on the primal-dual method is proposed to solve the optimization problem. Results based on experimental measurements are discussed to prove the effectiveness of the proposal.","PeriodicalId":93182,"journal":{"name":"IEEE open journal of power electronics","volume":null,"pages":null},"PeriodicalIF":5.0,"publicationDate":"2024-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10565993","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141474853","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-06-19DOI: 10.1109/OJPEL.2024.3414973
Lucas Melanson;Justin Woelfle;Majid Pahlevani
This article presents a novel multi-level current-driven DC-DC converter along with a modulation scheme that is able to maintain a consistently high efficiency across a wide range of input voltages. This proposed circuit is targeted to applications with a wide range of operating conditions, e.g., PV microinverters, energy storage, etc. Industry standard converters such as the flyback and the LLC resonant converter struggle to accommodate the wide range of voltages, and their efficiency suffers when operating points deviate from the nominal. The proposed approach takes advantage of the multi-level structure and flexibility of the modulation scheme to achieve high performance for a wide operating range. In addition to theoretical analysis of the operation of the converter, this paper demonstrates the functionality and performance of a laboratory prototype in direct comparison to resonant converters to show its superior performance across a wide range. The results validate the benefits of the proposed topology and show a significantly flattened efficiency curve over a wide range of input voltages (0.56% variation over an input voltage range of 32 V to 48 V).
本文介绍了一种新型多电平电流驱动 DC-DC 转换器和一种调制方案，该方案能够在宽输入电压范围内保持稳定的高效率。该电路适用于各种工作条件下的应用，如光伏微型逆变器、储能等。反激式和 LLC 谐振转换器等行业标准转换器难以适应宽电压范围，当工作点偏离额定值时，其效率也会受到影响。所提出的方法利用多电平结构和调制方案的灵活性，在宽工作范围内实现了高性能。除了对转换器的运行进行理论分析外，本文还演示了实验室原型的功能和性能，并与谐振转换器进行了直接比较，以显示其在宽范围内的优越性能。结果验证了所提出的拓扑结构的优势，并显示在宽输入电压范围内效率曲线明显趋于平缓（在 32 V 至 48 V 的输入电压范围内变化率为 0.56%）。
{"title":"A Novel Multilevel Current-Driven DC-DC Converter for Wide Range Applications","authors":"Lucas Melanson;Justin Woelfle;Majid Pahlevani","doi":"10.1109/OJPEL.2024.3414973","DOIUrl":"https://doi.org/10.1109/OJPEL.2024.3414973","url":null,"abstract":"This article presents a novel multi-level current-driven DC-DC converter along with a modulation scheme that is able to maintain a consistently high efficiency across a wide range of input voltages. This proposed circuit is targeted to applications with a wide range of operating conditions, e.g., PV microinverters, energy storage, etc. Industry standard converters such as the flyback and the LLC resonant converter struggle to accommodate the wide range of voltages, and their efficiency suffers when operating points deviate from the nominal. The proposed approach takes advantage of the multi-level structure and flexibility of the modulation scheme to achieve high performance for a wide operating range. In addition to theoretical analysis of the operation of the converter, this paper demonstrates the functionality and performance of a laboratory prototype in direct comparison to resonant converters to show its superior performance across a wide range. The results validate the benefits of the proposed topology and show a significantly flattened efficiency curve over a wide range of input voltages (0.56% variation over an input voltage range of 32 V to 48 V).","PeriodicalId":93182,"journal":{"name":"IEEE open journal of power electronics","volume":null,"pages":null},"PeriodicalIF":5.0,"publicationDate":"2024-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10564111","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141474852","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-06-18DOI: 10.1109/OJPEL.2024.3416195
Ahmed K. Khamis;Mohammed Agamy
This article proposes an integration between a graph framework for circuit representation and a Graph neural network (GNN) model suitable for different machine learning (ML) applications. Furthermore, the paper highlights design steps for tailoring and using the GNN-based ML model for converter performance predictions based on converter circuit level and internal parameter variations. Regardless of the number of components or connections present in a converter circuit, the proposed model can be readily scaled to incorporate different converter circuit topologies and may be used to analyze such circuits regardless of the number of components used or control parameters varied. To enable the use of ML methods and applications, all physical and switching circuit properties including operating mode, components and circuit behavior must be accurately mapped to graph representation. The model scalability to other circuit types and different connections and circuits elements is also tested, while being studied in the most common DC-AC inverter in grid connected systems including filter and filterless configurations. The filtered and filterless DC-AC inverter circuits are used to evaluate the model, scoring $R^{2}$ greater than 99% in most cases and a mean square error (MSE) tending to zero.
本文提出了一种用于电路表示的图框架与适用于不同机器学习（ML）应用的图神经网络（GNN）模型之间的集成。此外，本文还重点介绍了根据转换器电路水平和内部参数变化，定制和使用基于 GNN 的 ML 模型进行转换器性能预测的设计步骤。无论转换器电路中存在多少组件或连接，所提出的模型都可以很容易地进行扩展，以纳入不同的转换器电路拓扑结构，并可用于分析这些电路，而无需考虑所使用组件的数量或控制参数的变化。为了能够使用 ML 方法和应用，必须将所有物理和开关电路属性（包括工作模式、组件和电路行为）准确映射到图形表示法中。我们还测试了模型对其他电路类型、不同连接和电路元件的可扩展性，并对并网系统中最常见的直流-交流逆变器（包括滤波和无滤波配置）进行了研究。滤波和无滤波直流交流逆变器电路用于评估模型，在大多数情况下，R^{2}$大于 99%，均方误差 (MSE) 趋于零。
{"title":"Circuit Dynamics Prediction via Graph Neural Network & Graph Framework Integration: Three Phase Inverter Case Study","authors":"Ahmed K. Khamis;Mohammed Agamy","doi":"10.1109/OJPEL.2024.3416195","DOIUrl":"https://doi.org/10.1109/OJPEL.2024.3416195","url":null,"abstract":"This article proposes an integration between a graph framework for circuit representation and a Graph neural network (GNN) model suitable for different machine learning (ML) applications. Furthermore, the paper highlights design steps for tailoring and using the GNN-based ML model for converter performance predictions based on converter circuit level and internal parameter variations. Regardless of the number of components or connections present in a converter circuit, the proposed model can be readily scaled to incorporate different converter circuit topologies and may be used to analyze such circuits regardless of the number of components used or control parameters varied. To enable the use of ML methods and applications, all physical and switching circuit properties including operating mode, components and circuit behavior must be accurately mapped to graph representation. The model scalability to other circuit types and different connections and circuits elements is also tested, while being studied in the most common DC-AC inverter in grid connected systems including filter and filterless configurations. The filtered and filterless DC-AC inverter circuits are used to evaluate the model, scoring \u0000<inline-formula><tex-math>$R^{2}$</tex-math></inline-formula>\u0000 greater than 99% in most cases and a mean square error (MSE) tending to zero.","PeriodicalId":93182,"journal":{"name":"IEEE open journal of power electronics","volume":null,"pages":null},"PeriodicalIF":5.0,"publicationDate":"2024-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10560473","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141500341","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-06-13DOI: 10.1109/OJPEL.2024.3414172
Aris van Ieperen;Stijn Derammelaere;Ben Minnaert
Capacitive wireless power transfer utilizes capacitive coupling to transfer electrical energy wirelessly. Due to the nature of the coupling, it is seen as a well-suited technique for single input multiple outputs configurations. For these systems, optimal solutions for power transfer and efficiency exist, however, with variation in distance or alignment, the coupling varies and as a result, these optimal solutions vary. Therefore, there is a need for coupling-independent approaches to keep these systems within their optimal operating conditions. In this work, we propose a frequency-agile mode, using frequency bifurcation, that allows for a nearly coupling-independent power transfer and efficiency regime for a capacitive wireless power transfer system with one transmitter and multiple receivers. The conditions for bifurcation are described and analytical expressions for the power and transducer gains are determined. It is shown that, when operating at the secondary resonances, nearly constant efficiency and power transfer to the load can be achieved. An experimental setup was realized and the results validate the theoretical results, showcasing a coupling-independent efficiency and power output with a more than four-fold increase in output power at the cost of less than $5%$ reduction in absolute efficiency.
{"title":"Coupling-Independent Capacitive Wireless Power Transfer With One Transmitter and Multiple Receivers Using Frequency Bifurcation","authors":"Aris van Ieperen;Stijn Derammelaere;Ben Minnaert","doi":"10.1109/OJPEL.2024.3414172","DOIUrl":"https://doi.org/10.1109/OJPEL.2024.3414172","url":null,"abstract":"Capacitive wireless power transfer utilizes capacitive coupling to transfer electrical energy wirelessly. Due to the nature of the coupling, it is seen as a well-suited technique for single input multiple outputs configurations. For these systems, optimal solutions for power transfer and efficiency exist, however, with variation in distance or alignment, the coupling varies and as a result, these optimal solutions vary. Therefore, there is a need for coupling-independent approaches to keep these systems within their optimal operating conditions. In this work, we propose a frequency-agile mode, using frequency bifurcation, that allows for a nearly coupling-independent power transfer and efficiency regime for a capacitive wireless power transfer system with one transmitter and multiple receivers. The conditions for bifurcation are described and analytical expressions for the power and transducer gains are determined. It is shown that, when operating at the secondary resonances, nearly constant efficiency and power transfer to the load can be achieved. An experimental setup was realized and the results validate the theoretical results, showcasing a coupling-independent efficiency and power output with a more than four-fold increase in output power at the cost of less than \u0000<inline-formula><tex-math>$5%$</tex-math></inline-formula>\u0000 reduction in absolute efficiency.","PeriodicalId":93182,"journal":{"name":"IEEE open journal of power electronics","volume":null,"pages":null},"PeriodicalIF":5.0,"publicationDate":"2024-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10556644","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141435409","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-06-13DOI: 10.1109/OJPEL.2024.3414151
Z. Li;R. Mirzadarani;M. Ghaffarian Niasar;M. Itraj;L. van Lieshout;P. Bauer;Z. Qin
In the production of green hydrogen, electrolyzers draw power from renewable energy sources. In this paper, the design of Solid State Transformer (SST) for large-scale H 2 electrolyzers is benchmarked. The three most promising topologies are chosen for design and comparison, including Modular Multi-level Converter (MMC) based SST, Modular Multi-level Resonant (MMR) based SST, and Input-Series-Output-Parallel (ISOP) based SST. The distance between converter towers for insulation and maintenance, the insulation system of the transformer, and the cooling system are designed with practical considerations in order to have an accurate estimation of the volume and weight of the SST. Losses in the switches are calculated based on equations, and losses in passive components are calculated based on FEM simulation. The operating frequency for each topology is optimized to minimize loss, weight, and volume. The best of each topology is then compared with each other to identify the most suitable one for large-scale H 2 electrolyzers.
{"title":"Medium-Voltage Solid-State Transformer Design for Large-Scale H2 Electrolyzers","authors":"Z. Li;R. Mirzadarani;M. Ghaffarian Niasar;M. Itraj;L. van Lieshout;P. Bauer;Z. Qin","doi":"10.1109/OJPEL.2024.3414151","DOIUrl":"https://doi.org/10.1109/OJPEL.2024.3414151","url":null,"abstract":"In the production of green hydrogen, electrolyzers draw power from renewable energy sources. In this paper, the design of Solid State Transformer (SST) for large-scale H\u0000<sub>2</sub>\u0000 electrolyzers is benchmarked. The three most promising topologies are chosen for design and comparison, including Modular Multi-level Converter (MMC) based SST, Modular Multi-level Resonant (MMR) based SST, and Input-Series-Output-Parallel (ISOP) based SST. The distance between converter towers for insulation and maintenance, the insulation system of the transformer, and the cooling system are designed with practical considerations in order to have an accurate estimation of the volume and weight of the SST. Losses in the switches are calculated based on equations, and losses in passive components are calculated based on FEM simulation. The operating frequency for each topology is optimized to minimize loss, weight, and volume. The best of each topology is then compared with each other to identify the most suitable one for large-scale H\u0000<sub>2</sub>\u0000 electrolyzers.","PeriodicalId":93182,"journal":{"name":"IEEE open journal of power electronics","volume":null,"pages":null},"PeriodicalIF":5.0,"publicationDate":"2024-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10556593","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141453480","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-06-13DOI: 10.1109/OJPEL.2024.3414141
Abraham López;Theyllor H. Oliveira;Manuel Arias;Pablo Fernández Miaja;José A. Villarejo;Arturo Fernández
The use of a DC/DC Transformer (DCX), composed of low-power individual modules with automatic voltage and power sharing will be presented as a possible solution to increase the input voltage and output power ranges of DCX systems. The input voltage range will be increased through just Input Series – Output Parallel (ISOP) connection and the increased power handling capability will be achieved by Input Parallel – Output Parallel (IPOP) connection. With these modules, it is possible to achieve natural power and voltage sharing using only a common synchronization signal between modules. Thanks to this natural equalization, ISOP and IPOP concepts are extended to form a DCX with a matrix structure which will be tolerant to the loss of one module without compromising the power handling capabilities. The proposed topology is analyzed in detail, including the mechanisms that can affect the distribution of voltages and currents. A reliability analysis and the response of the modular system under a failure situation have also been included. The validation of this proposal has been carried out using a modular prototype for an input voltage and an output voltage of 56 V and 28 V respectively, for a rated power of 200 W, and for a switching frequency of 365 kHz.
{"title":"Modular Fault Tolerant DC/DC Transformer Enabled by Natural Power Sharing","authors":"Abraham López;Theyllor H. Oliveira;Manuel Arias;Pablo Fernández Miaja;José A. Villarejo;Arturo Fernández","doi":"10.1109/OJPEL.2024.3414141","DOIUrl":"https://doi.org/10.1109/OJPEL.2024.3414141","url":null,"abstract":"The use of a DC/DC Transformer (DCX), composed of low-power individual modules with automatic voltage and power sharing will be presented as a possible solution to increase the input voltage and output power ranges of DCX systems. The input voltage range will be increased through just Input Series – Output Parallel (ISOP) connection and the increased power handling capability will be achieved by Input Parallel – Output Parallel (IPOP) connection. With these modules, it is possible to achieve natural power and voltage sharing using only a common synchronization signal between modules. Thanks to this natural equalization, ISOP and IPOP concepts are extended to form a DCX with a matrix structure which will be tolerant to the loss of one module without compromising the power handling capabilities. The proposed topology is analyzed in detail, including the mechanisms that can affect the distribution of voltages and currents. A reliability analysis and the response of the modular system under a failure situation have also been included. The validation of this proposal has been carried out using a modular prototype for an input voltage and an output voltage of 56 V and 28 V respectively, for a rated power of 200 W, and for a switching frequency of 365 kHz.","PeriodicalId":93182,"journal":{"name":"IEEE open journal of power electronics","volume":null,"pages":null},"PeriodicalIF":5.0,"publicationDate":"2024-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10556642","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141439462","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In recent years, the interest in DC systems has increased dramatically because of some key advantages, in terms of efficiency and reliability, that this technology can offer compared to AC systems in applications such as shipboard distribution, more electric aircrafts, DC microgrids, battery protection, and photovoltaics. In this context, DC circuit breakers based on power semiconductors, the so-called solid-state circuit breakers, are becoming a popular choice because of their fast intervention speed, which is typically on the order of microseconds. Unfortunately, power electronics are vulnerable to “breakdown”, which is a dangerous operating condition triggered by overvoltages. During current interruption, the energy stored in the inductive elements of the system must be dissipated, and this typically creates a very high voltage spike on the interrupting component, which is the breaker pole. This phenomenon, if not controlled, could lead to the premature failure of the semiconductor inside the solid-state circuit breaker. For this reason, suitable techniques aimed to control the voltage gradient and overshoot during interruption have been presented in the literature. This paper analyzes and compares the performances of the voltage-clamping solutions presented in the technical literature, which range from simple passive devices to more advanced solutions.
{"title":"A Review of Voltage-Clamping Methods for Solid-State Circuit Breakers","authors":"Gioele Gregis;Luigi Piegari;Luca Raciti;Thomas Masper","doi":"10.1109/OJPEL.2024.3411110","DOIUrl":"https://doi.org/10.1109/OJPEL.2024.3411110","url":null,"abstract":"In recent years, the interest in DC systems has increased dramatically because of some key advantages, in terms of efficiency and reliability, that this technology can offer compared to AC systems in applications such as shipboard distribution, more electric aircrafts, DC microgrids, battery protection, and photovoltaics. In this context, DC circuit breakers based on power semiconductors, the so-called solid-state circuit breakers, are becoming a popular choice because of their fast intervention speed, which is typically on the order of microseconds. Unfortunately, power electronics are vulnerable to “breakdown”, which is a dangerous operating condition triggered by overvoltages. During current interruption, the energy stored in the inductive elements of the system must be dissipated, and this typically creates a very high voltage spike on the interrupting component, which is the breaker pole. This phenomenon, if not controlled, could lead to the premature failure of the semiconductor inside the solid-state circuit breaker. For this reason, suitable techniques aimed to control the voltage gradient and overshoot during interruption have been presented in the literature. This paper analyzes and compares the performances of the voltage-clamping solutions presented in the technical literature, which range from simple passive devices to more advanced solutions.","PeriodicalId":93182,"journal":{"name":"IEEE open journal of power electronics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-06-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10551911","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141422563","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-06-06DOI: 10.1109/OJPEL.2024.3410908
Amr Radwan;Mahmoud A. Elshenawy;Yasser Abdel-Rady I. Mohamed;Ehab Fahmy El-Saadany
This paper presents a grid-forming (GFM) voltage-source inverter (VSI) with direct current regulation for a hybrid wind-solar generator, enabling stable operation at very weak grid conditions and under faults. The GFM-VSI interfaces a hybrid wind-solar generator without an intermediate dc-dc conversion to increase the system efficiency. The wind generator comprises a wind turbine with a permanent magnet synchronous generator (PMSG) interfaced by a voltage-source rectifier (VSR). The PMSG-VSR and a solar photovoltaic (PV) array are connected to the GFM-VSI's dc-side. The VSR is responsible for extracting wind power with a power reserve option. The GFM-VSI is implemented to extract solar power with a power reserve capability and support the grid voltage or reactive power. The stable operation of the proposed system is validated under very weak grid conditions, and it is shown that a similar hybrid wind-solar system with grid-following control is unstable under the same weak grid conditions. A complete small-signal state-space model of the proposed hybrid system is developed and analyzed. Nonlinear time-domain simulations and real-time simulation tests verify the model's accuracy and show the proposed system's effective performance under challenging operating scenarios, such as grid uncertainties and faults.
{"title":"Grid-Forming Voltage-Source Inverter for Hybrid Wind-Solar Systems Interfacing Weak Grids","authors":"Amr Radwan;Mahmoud A. Elshenawy;Yasser Abdel-Rady I. Mohamed;Ehab Fahmy El-Saadany","doi":"10.1109/OJPEL.2024.3410908","DOIUrl":"https://doi.org/10.1109/OJPEL.2024.3410908","url":null,"abstract":"This paper presents a grid-forming (GFM) voltage-source inverter (VSI) with direct current regulation for a hybrid wind-solar generator, enabling stable operation at very weak grid conditions and under faults. The GFM-VSI interfaces a hybrid wind-solar generator without an intermediate dc-dc conversion to increase the system efficiency. The wind generator comprises a wind turbine with a permanent magnet synchronous generator (PMSG) interfaced by a voltage-source rectifier (VSR). The PMSG-VSR and a solar photovoltaic (PV) array are connected to the GFM-VSI's dc-side. The VSR is responsible for extracting wind power with a power reserve option. The GFM-VSI is implemented to extract solar power with a power reserve capability and support the grid voltage or reactive power. The stable operation of the proposed system is validated under very weak grid conditions, and it is shown that a similar hybrid wind-solar system with grid-following control is unstable under the same weak grid conditions. A complete small-signal state-space model of the proposed hybrid system is developed and analyzed. Nonlinear time-domain simulations and real-time simulation tests verify the model's accuracy and show the proposed system's effective performance under challenging operating scenarios, such as grid uncertainties and faults.","PeriodicalId":93182,"journal":{"name":"IEEE open journal of power electronics","volume":null,"pages":null},"PeriodicalIF":5.0,"publicationDate":"2024-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10551428","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141453479","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：