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A Novel Multilevel Current-Driven DC-DC Converter for Wide Range Applications 适用于大范围应用的新型多电平电流驱动 DC-DC 转换器
IF 5 Q1 ENGINEERING, ELECTRICAL & ELECTRONIC Pub Date : 2024-06-19 DOI: 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%)。
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引用次数: 0
Circuit Dynamics Prediction via Graph Neural Network & Graph Framework Integration: Three Phase Inverter Case Study 通过图神经网络和图框架集成进行电路动态预测:三相逆变器案例研究
IF 5 Q1 ENGINEERING, ELECTRICAL & ELECTRONIC Pub Date : 2024-06-18 DOI: 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。
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引用次数: 0
Coupling-Independent Capacitive Wireless Power Transfer With One Transmitter and Multiple Receivers Using Frequency Bifurcation 利用频率分岔实现与耦合无关的单发射器和多接收器电容式无线电力传输
IF 5 Q1 ENGINEERING, ELECTRICAL & ELECTRONIC Pub Date : 2024-06-13 DOI: 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.
电容式无线电力传输利用电容耦合来无线传输电能。由于耦合的性质,它被视为一种非常适合单输入多输出配置的技术。对于这些系统,存在着功率传输和效率的最佳解决方案,但是,随着距离或排列的变化,耦合也会发生变化,因此,这些最佳解决方案也会随之变化。因此,有必要采用与耦合无关的方法,使这些系统保持在最佳运行条件下。在这项工作中,我们利用频率分岔提出了一种频率敏捷模式,该模式可为具有一个发射器和多个接收器的电容式无线电力传输系统提供几乎与耦合无关的功率传输和效率机制。对分岔条件进行了描述,并确定了功率和换能器增益的分析表达式。结果表明,在次级谐振下工作时,可以实现近乎恒定的效率和向负载的功率传输。实验装置已经实现,结果验证了理论结果,展示了与耦合无关的效率和功率输出,输出功率增加了四倍多,而绝对效率降低了不到 5 美元。
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引用次数: 0
Medium-Voltage Solid-State Transformer Design for Large-Scale H2 Electrolyzers 用于大型 H2 电解槽的中压固态变压器设计
IF 5 Q1 ENGINEERING, ELECTRICAL & ELECTRONIC Pub Date : 2024-06-13 DOI: 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 H2 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 H2 electrolyzers.
在生产绿色氢气的过程中,电解槽从可再生能源中获取电能。本文对用于大规模氢气电解槽的固态变压器(SST)的设计进行了基准测试。本文选择了三种最有前途的拓扑结构进行设计和比较,包括基于模块化多电平转换器(MMC)的 SST、基于模块化多电平谐振(MMR)的 SST 和基于输入-串联-输出-并联(ISOP)的 SST。为了准确估算 SST 的体积和重量,我们在设计时实际考虑了用于绝缘和维护的变流器塔之间的距离、变压器的绝缘系统和冷却系统。开关的损耗根据方程式计算,无源元件的损耗根据有限元模拟计算。对每种拓扑结构的工作频率进行优化,以尽量减少损耗、重量和体积。然后对每种拓扑结构的最佳结果进行比较,以确定最适合大规模 H2 电解槽的拓扑结构。
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引用次数: 0
Modular Fault Tolerant DC/DC Transformer Enabled by Natural Power Sharing 通过自然功率共享实现模块化容错 DC/DC 变压器
IF 5 Q1 ENGINEERING, ELECTRICAL & ELECTRONIC Pub Date : 2024-06-13 DOI: 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.
直流/直流变压器(DCX)由具有自动电压和功率共享功能的低功耗单个模块组成,将作为一种可能的解决方案用于提高 DCX 系统的输入电压和输出功率范围。只需通过输入串联-输出并联(ISOP)连接即可增加输入电压范围,而通过输入并联-输出并联(IPOP)连接则可提高功率处理能力。使用这些模块,只需在模块之间使用一个共同的同步信号,就能实现自然功率和电压共享。得益于这种自然均衡,ISOP 和 IPOP 概念被扩展为矩阵结构的 DCX,这种矩阵结构可以承受一个模块的损耗,而不会影响功率处理能力。对所提出的拓扑结构进行了详细分析,包括可能影响电压和电流分布的机制。还包括可靠性分析和模块系统在故障情况下的响应。使用模块化原型验证了这一建议,输入电压和输出电压分别为 56 V 和 28 V,额定功率为 200 W,开关频率为 365 kHz。
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引用次数: 0
A Review of Voltage-Clamping Methods for Solid-State Circuit Breakers 固态断路器电压钳位方法综述
Q1 ENGINEERING, ELECTRICAL & ELECTRONIC Pub Date : 2024-06-07 DOI: 10.1109/OJPEL.2024.3411110
Gioele Gregis;Luigi Piegari;Luca Raciti;Thomas Masper
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.
近年来,人们对直流系统的兴趣急剧增加,因为与交流系统相比,直流技术在效率和可靠性方面具有一些关键优势,可应用于船上配电、更多电动飞机、直流微电网、电池保护和光伏发电等领域。在这种情况下,基于功率半导体的直流断路器,即所谓的固态断路器,因其介入速度快(通常为微秒级)而成为一种流行的选择。遗憾的是,电力电子器件容易发生 "击穿",这是一种由过电压引发的危险工作状态。在电流中断期间,系统电感元件中储存的能量必须耗散,这通常会在断路元件(即断路器极)上产生一个非常高的电压尖峰。这种现象如果不加以控制,可能会导致固态断路器内部的半导体过早失效。因此,文献中出现了旨在控制断路期间电压梯度和过冲的合适技术。本文分析并比较了技术文献中介绍的电压闭锁解决方案的性能,这些解决方案既有简单的无源装置,也有更先进的解决方案。
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引用次数: 0
Grid-Forming Voltage-Source Inverter for Hybrid Wind-Solar Systems Interfacing Weak Grids 用于弱电网风光互补系统的并网型电压源逆变器
IF 5 Q1 ENGINEERING, ELECTRICAL & ELECTRONIC Pub Date : 2024-06-06 DOI: 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.
本文介绍了一种并网(GFM)电压源逆变器(VSI),该逆变器具有直流调节功能,适用于风能和太阳能混合发电机,可在电网非常薄弱的条件下和故障情况下稳定运行。GFM-VSI 与风能-太阳能混合发电机连接,无需中间的直流-直流转换,以提高系统效率。风力发电机由风力涡轮机和永磁同步发电机(PMSG)以及电压源整流器(VSR)组成。PMSG-VSR 和太阳能光伏 (PV) 阵列连接到 GFM-VSI 的直流侧。VSR 负责提取具有功率储备选项的风能。GFM-VSI 用于提取具有功率储备能力的太阳能电力,并支持电网电压或无功功率。在电网非常薄弱的条件下,验证了所提系统的稳定运行,并表明在同样薄弱的电网条件下,采用电网跟踪控制的类似风光互补系统是不稳定的。建立并分析了拟议混合系统的完整小信号状态空间模型。非线性时域仿真和实时仿真测试验证了模型的准确性,并显示了拟议系统在电网不确定性和故障等具有挑战性的运行情况下的有效性能。
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引用次数: 0
Ripple Reduction of Active Split DC-Link 4-Wire Inverters by Phase-Shifted Multi-Carrier Modulation 通过移相多载波调制降低有源分路直流链路 4 线制逆变器的纹波
Q1 ENGINEERING, ELECTRICAL & ELECTRONIC Pub Date : 2024-06-04 DOI: 10.1109/OJPEL.2024.3409065
Ezio Gallo;Davide Biadene;Igino Toigo;Tommaso Caldognetto
This paper considers a multi-carrier modulation in which the phase-shifts between the carriers are adjusted to reduce the rms current flowing into the active split dc-link capacitors of four-wire three-phase inverters when the neutral node is modulated with the third harmonic. Capacitors current reduction is beneficial in terms of volume, losses, and components stresses. Considering the current ripple combination of the phases and neutral currents, the proposed approach reduces the rms current through the split dc-link capacitors compared to a standard single-carrier pulse-width modulation. It is shown that the amount of reduction depends on the modulation index and the ratio between the neutral and the output inductors. Besides, it is not significantly influenced by the unbalancing current, in the considered topology, in which the split dc-link capacitors are aimed to regulate the neutral-point voltage. Guidelines for selecting suitable phase-shifts in practical cases based on the inverter operating point are discussed. The results are demonstrated on an experimental prototype.
本文研究了一种多载波调制方法,当中性点受到三次谐波调制时,通过调整载波之间的相移来降低流向四线制三相逆变器有源分路直流链路电容器的均方根电流。电容器电流的降低有利于减少体积、损耗和元件应力。考虑到相电流和中性点电流的纹波组合,与标准的单载波脉宽调制相比,所提出的方法降低了通过分路直流链路电容器的均方根电流。结果表明,降低的幅度取决于调制指数以及中性线和输出电感器之间的比率。此外,在所考虑的拓扑结构中,分路直流链路电容器的目的是调节中性点电压,因此它不会受到不平衡电流的明显影响。讨论了在实际情况下根据逆变器工作点选择合适相移的准则。实验原型对结果进行了演示。
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引用次数: 0
A Partially Rated LC Trap Type AC Filter for Grid-Tied Voltage Source Converters 用于并网电压源转换器的部分额定 LC 陷波器型交流滤波器
Q1 ENGINEERING, ELECTRICAL & ELECTRONIC Pub Date : 2024-06-03 DOI: 10.1109/OJPEL.2024.3408272
Srinivas Gulur;Vishnu Mahadeva Iyer;Subhashish Bhattacharya
$AC$ power filters play an important role in limiting the high-frequency current harmonics injected by grid-tied voltage source converters (VSCs). Amongst the various types of filters, $LCL$ filters with integrated $LC$ traps have become popular due to their ability to achieve a size reduction of the grid side inductor while demonstrating a similar current harmonic mitigation performance as a traditional $LCL$ filter. In this article, a passively damped filter network with a partially rated $LC$ trap (also referred to as the $Ltext{-}PTtext{-}L$ filter) is proposed and delineated. The proposed $Ltext{-}PTtext{-}L$ filter provides a $-60;text{dB/dec}$ roll-off characteristics at frequencies greater than switching frequency. Additionally, it is also demonstrated that this proposed $Ltext{-}PTtext{-}L$ filter has smaller voltage ratings for two of its shunt-connected capacitor components due to the specific placement of the damping resistor. A systematic analysis of the proposed $Ltext{-}PTtext{-}L$ filter is elucidated to design and select the component parameters. Steady-state and transient experimental results captured from a grid-tied 2-Level, 3$phi$ VSC prototype are provided to validate the grid current harmonic filtering capability, reduced voltage ratings of the two shunt capacitors and passive damping performance of the proposed $Ltext{-}PTtext{-}L$ filter. The proposed approach can achieve 19% and 36% filter shunt branch volume reduction for low voltage (208 V, 60 Hz) and medium voltage (4.16 kV, 60 Hz) grid-tied inverter systems, respectively, compared to state-of-the-art $LCL$ filters with integrated $LC$ traps.
交流电源滤波器在限制并网电压源转换器(VSC)注入的高频电流谐波方面发挥着重要作用。在各种类型的滤波器中,集成了$LC$陷波器的$LCL$滤波器由于能够减小电网侧电感器的尺寸,同时具有与传统$LCL$滤波器类似的电流谐波缓解性能而广受欢迎。本文提出并描述了一种带有部分额定 $LC$ 陷波器的无源阻尼滤波器网络(也称为 $Ltext{-}PTtext{-}L$ 滤波器)。所提出的 $Ltext{-}PTtext{-}L$ 滤波器在频率高于开关频率时具有 $-60;text{dB/dec}$ 的滚降特性。此外,研究还表明,由于阻尼电阻器的特定位置,这种拟议的 $Ltext{-}PTtext{-}L$ 滤波器的两个并联电容器元件的额定电压较小。对所提出的 $Ltext{-}PTtext{-}L$ 滤波器进行了系统分析,以设计和选择元件参数。从并网的 2 级 3$phi$ VSC 原型中获取的稳态和瞬态实验结果验证了拟议的 $Ltext{-}PTtext{-}L$ 滤波器的电网电流谐波滤除能力、两个并联电容器的额定电压降低以及无源阻尼性能。与集成了 $LC$ 陷波器的最先进 $LCL$ 滤波器相比,所提出的方法可使低压(208 V,60 Hz)和中压(4.16 kV,60 Hz)并网逆变器系统的滤波器并联支路体积分别减少 19% 和 36%。
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引用次数: 0
Comparative Analysis of Wireless Power Transfer Couplers for Unmanned Aerial Vehicles and Drones 用于无人机和无人驾驶飞机的无线功率传输耦合器对比分析
Q1 ENGINEERING, ELECTRICAL & ELECTRONIC Pub Date : 2024-04-30 DOI: 10.1109/OJPEL.2024.3395174
Uvir Gordhan;Sampath Jayalath
Several magnetic couplers have been presented for IPT-based charging of unmanned aerial vehicles (UAV) with different sizes, transmission distances, power ratings, and landing gears. Therefore, it is hard to conclude the superiority or suitability of existing couplers for a given UAV application without evaluating their performance under common indices. Thus, a comparative analysis of existing IPT couplers for UAVs is conducted in this article, considering electromagnetic and physical performance indices. This includes efficiency, leakage magnetic field, misalignment tolerance, receiver coil volumetric power density, weight, and total harmonic distortion (THD) of transmitter and receiver currents. The validity of the analysis is experimentally supported. This article identifies the following: relative advantages and disadvantages of existing couplers, the best couplers suited for different landing gears of UAVs in the rotary-wing category, the impact of compensation on UAV coupler performance, and the best overall performing couplers. Moreover, future directions are suggested based on the drawbacks identified through analysis.
针对基于 IPT 的无人飞行器(UAV)充电,已经推出了几种磁耦合器,其尺寸、传输距离、额定功率和起落架各不相同。因此,如果不评估现有耦合器在通用指标下的性能,就很难断定其优越性或是否适用于特定的无人飞行器应用。因此,本文在考虑电磁和物理性能指标的基础上,对用于无人机的现有 IPT 耦合器进行了比较分析。其中包括效率、漏磁场、偏差容限、接收器线圈体积功率密度、重量以及发射器和接收器电流的总谐波失真(THD)。实验证明了分析的有效性。本文指出了以下几点:现有耦合器的相对优缺点、适合旋转翼无人机不同起落架的最佳耦合器、补偿对无人机耦合器性能的影响以及整体性能最佳的耦合器。此外,还根据分析发现的缺点提出了未来的发展方向。
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引用次数: 0
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IEEE open journal of power electronics
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