Journal articles: 'Full bridge submodule'

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Liu, Wenjun, Genxu Chen, Yimiao Wang, Bicheng Xu, and Yan Chen. "A Series/Parallel Full-bridge MMC with Submodule Capacitor Voltage Self-balancing Capability." Journal of Physics: Conference Series 3012, no. 1 (2025): 012077. https://doi.org/10.1088/1742-6596/3012/1/012077.

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Abstract Modular Multilevel Converters (MMC) are the key equipment in High Voltage Direct Current (HVDC) systems, but they still face challenges such as DC fault clearance and excessive computation for submodule capacitor voltage sequencing. This paper presents an improved full-bridge MMC (MF-MMC) with submodule capacitor voltage self-balancing and DC fault clearance capability. By using two reverse-series IGBTs, adjacent full-bridge submodules are reconfigured from series to parallel, establishing a parallel path between adjacent capacitors. The MF-MMC enables voltage self-balancing between capacitors of different submodules within the same arm without the need for monitoring the capacitor voltage, significantly reducing the complexity and computational load of the controller. At the same time, the parallel connection of capacitors reduces the output of individual capacitors, thereby decreasing voltage fluctuations. A dynamic distribution voltage balancing control strategy is proposed to optimize the switching of power devices, reducing overall switching losses. Finally, MATLAB experimental results validate the effectiveness of this topology in terms of submodule parallel capabilities and DC fault clearance.

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Kang, Feel-Soon, and Sung-Geun Song. "Life-Cycle Expectation Using Fault-Tree Analysis for Improved Hybrid Submodule in HVDC System." Electronics 10, no. 2 (2021): 133. http://dx.doi.org/10.3390/electronics10020133.

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An improved hybrid submodule employs a direct current (DC) short current protection function to improve the reliability of a high-voltage direct current (HVDC) system. However, it increases the number of circuit components to implement the protection. So, we need to evaluate the relationship between the protection function and the increased number of circuit components to assess whether the improved hybrid submodule (IHSM) is suitable to practical application or not from the viewpoint of reliability. Although conventional part count failure analysis considers the type and the number of parts, it cannot reflect the operational characteristics of the submodule. To overcome this problem, we design a fault tree that reflects the operational characteristics of IHSM and calculates the failure rate by using MIL-HDBK-217F. By part count failure analysis (PCA) and fault-tree analysis (FTA), we prove the high reliability of IHSM compared to half-bridge, full-bridge, and clamped-double submodules.

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Kang, Feel-Soon, and Sung-Geun Song. "Life-Cycle Expectation Using Fault-Tree Analysis for Improved Hybrid Submodule in HVDC System." Electronics 10, no. 2 (2021): 133. http://dx.doi.org/10.3390/electronics10020133.

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An improved hybrid submodule employs a direct current (DC) short current protection function to improve the reliability of a high-voltage direct current (HVDC) system. However, it increases the number of circuit components to implement the protection. So, we need to evaluate the relationship between the protection function and the increased number of circuit components to assess whether the improved hybrid submodule (IHSM) is suitable to practical application or not from the viewpoint of reliability. Although conventional part count failure analysis considers the type and the number of parts, it cannot reflect the operational characteristics of the submodule. To overcome this problem, we design a fault tree that reflects the operational characteristics of IHSM and calculates the failure rate by using MIL-HDBK-217F. By part count failure analysis (PCA) and fault-tree analysis (FTA), we prove the high reliability of IHSM compared to half-bridge, full-bridge, and clamped-double submodules.

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Ali, Salman, Santiago Bogarra, Muhammad Mansooor Khan, Ahmad Taha, Pyae Pyae Phyo, and Yung-Cheol Byun. "Prospective Submodule Topologies for MMC-BESS and Its Control Analysis with HBSM." Electronics 12, no. 1 (2022): 20. http://dx.doi.org/10.3390/electronics12010020.

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Battery energy storage systems and multilevel converters are the most essential constituents of modern medium voltage networks. In this regard, the modular multilevel converter offers numerous advantages over other multilevel converters. The key feature of modular multilevel converter is its capability to integrate small battery packs in a split manner, given the opportunity to submodules to operate at considerably low voltages. In this paper, we focus on study of potential SMs for modular multilevel converter based battery energy storage system while, keeping in view the inconsistency of secondary batteries. Although, selecting a submodule for modular multilevel converter based battery energy storage system, the state of charge control complexity is a key concern, which increases as the voltage levels increase. This study suggests that the half-bridge, clamped single, and full-bridge submodules are the most suitable submodules for modular multilevel converter based battery energy storage system since, they provide simplest state of charge control due to integration of one battery pack along with other advantages among all 24 submodule topologies. Depending on submodules analysis, the modular multilevel converter based battery energy storage system based on half-bridge submodules is investigated by splitting it into AC and DC equivalent circuits to acquire the AC and DC side power controls along with an state of charge control. Subsequently, to validate different control modes, a downscaled laboratory prototype has been developed.

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Meng, Xinhan, Ke-Jun Li, Zhuodi Wang, Wenning Yan, and Jianguo Zhao. "A Hybrid MMC Topology with dc Fault Ride-Through Capability for MTDC Transmission System." Mathematical Problems in Engineering 2015 (2015): 1–11. http://dx.doi.org/10.1155/2015/512471.

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This paper proposes a hybrid modular multilevel converter (MMC) topology based on mismatched-cascade mechanism. The blocking conditions of different submodule (SM) structures under dc fault are analyzed and a series double submodule is presented. With series-double submodules and mismatched-cascade submodules, the proposed hybrid MMC can ride-through the dc side short-circuit fault and provide an output voltage with the feature of low harmonic content. This hybrid MMC topology can be used in the VSC based multiterminal dc (VSC-MTDC) transmission system. The dc fault ride-through properties of the new structure and the total harmonic distortion (THD) are analyzed compared with the previous full-bridge and clamp-double architectures. An appropriate fault blocking procedure is presented, and a typical four-terminal dc transmission simulation system is given in the power system simulation software. Finally, simulation of steady-state and dc bipolar short-circuit fault verifies that the MTDC system based on this new hybrid MMC topology is stabilized and can block the dc fault and return the nonfault parts to normal.

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Vidal-Albalate, Ricardo, and Jaume Forner. "Modeling and Enhanced Control of Hybrid Full Bridge–Half Bridge MMCs for HVDC Grid Studies." Energies 13, no. 1 (2020): 180. http://dx.doi.org/10.3390/en13010180.

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Modular multilevel converters (MMCs) are expected to play an important role in future high voltage direct current (HVDC) grids. Moreover, advanced MMC topologies may include various submodule (SM) types. In this sense, the modeling of MMCs is paramount for HVDC grid studies. Detailed models of MMCs are cumbersome for electromagnetic transient (EMT) programs due to the high number of components and large simulation times. For this reason, simplified models that reduce the computation times while reproducing the dynamics of the MMCs are needed. However, up to now, the models already developed do not consider hybrid MMCs, which consist of different types of SMs. In this paper, a procedure to simulate MMCs having different SM topologies is proposed. First, the structure of hybrid MMCs and the modeling method is presented. Next, an enhanced procedure to compute the number of SMs to be inserted that takes into account the different behavior of full-bridge SMs (FB-SMs) and half-bridge submodules (HB-SMs) is proposed in order to improve the steady-state and dynamic response of hybrid MMCs. Finally, the MMC model and its control are validated by means of detailed PSCAD simulations for both steady-state and transients conditions (AC and DC faults).

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Dang, HongShe, and JunDa Li. "CPS-SPWM Implementation Based on Multi - Controller Collaboration." Journal of Physics: Conference Series 2076, no. 1 (2021): 012112. http://dx.doi.org/10.1088/1742-6596/2076/1/012112.

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Abstract In order to improve the modularization degree of cascaded H-bridge converter and reduce the development cost, a modularized carrier phase shifted sine pulse width modulation (CPS-SPWM) based on multi-controller is proposed in this paper, which can easily increase or decrease the number of submodules in cascaded H-bridge. In order to solve the problem of coordination in multi-controller structure, a two-stage control structure is proposed, which uses the master controller to carry out closed-loop control for multiple slave controllers, and uses the approximate natural sampling method to realize digital CPS-SPWM modulation, which reduces computation and makes full use of controller resources. The experimental result shows that the stepped voltage waveform output by the proposed method at the AC side is of high quality and H bridge submodule is easy to be increased and decreased.

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Errigo, Florian, Leandro De Oliveira Porto, and Florent Morel. "Design Methodology Based on Prebuilt Components for Modular Multilevel Converters with Partial Integration of Energy Storage Systems." Energies 15, no. 14 (2022): 5006. http://dx.doi.org/10.3390/en15145006.

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To provide ancillary services in HVDC applications, modular multilevel converters (MMCs) with integration of energy storage systems are a promising solution as they take advantage of the modularity and the controllability of the stored energy. In these solutions, an energy storage system is connected to the DC capacitor of a submodule (SM) to make an energy storage submodule (ES-SM). An MMC with partial integration (MMC-PIES) is an MMC with each arm made of a mix of SMs and ES-SMs. In this paper, we propose a novel design methodology for these converters considering they are built based on existing prebuilt submodules, while design methodologies in the literature consider the SM and ES-SM characteristics to be degrees of freedom. Therefore, the proposed approach is closer to an industrial standpoint and computes the minimum number of ES-SMs to comply with requirements. We also include a new optimization method for the circulating currents needed to balance the energy in the SM and ES-SM capacitors. Design scenarios are presented. The results show that the value of the DC capacitance and the current limitation of the switches highly influence the design, restricting the possible operating points. In addition, half-bridge ES-SMs seem to be a more promising solution than full-bridge ES-SMs, reducing the number of ES-SMs.

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Chen, Yue, Chenglin Ren, Junyi Sheng, et al. "An Optimized Fault-Ride-Through Control Strategy of Hybrid MMC with Fewer FBSMs." Electronics 13, no. 10 (2024): 1797. http://dx.doi.org/10.3390/electronics13101797.

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The modular multilevel converter (MMC) has many advantages of low switching losses, good harmonic performance and high modularity structure in state-of-the-art HVDC applications. The full-bridge submodules (FBSMs) of the hybrid MMC can inherently output negative voltage to absorb fault currents, and consequently the hybrid MMC can ride through severe DC faults without blocking. During the DC fault-ride-through process, the submodule capacitor voltage and arm current of the MMC will be temporarily increased. These characteristics limit the proportion of the FBSMs, which should not be too low and thus increase the cost and operating losses of the hybrid MMC. In this paper, an improved sorting algorithm of SM capacitor voltage is established, and a novel virtual damping control strategy is proposed that can effectively suppress the increase in submodule capacitor voltage and arm current of the hybrid MMC during the DC fault-ride-through process. By adopting this optimization control, the proportion of FBSMs can be reduced significantly without deteriorating the fault-ride-through capability or safety of the MMC. The effectiveness of the proposed control is verified by careful theoretical analysis and detailed simulation results.

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Huang, Ming. "Submodule Capacitor Voltage Ripple Reduction of Full-Bridge Submodule-Based MMC (FBSM-MMC) with Non-Sinusoidal Voltage Injection." Energies 16, no. 11 (2023): 4305. http://dx.doi.org/10.3390/en16114305.

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The full-bridge submodule (FBSM)-based modular multilevel converter (FBSM-MMC) offers promising performance due to its ability to output negative FBSM voltage. This paper studies this ability of the FBSM-MMC under zero-sequence voltage injection (ZSVI) and second-order harmonic current injection (SHCI). The focus of the research is to redistribute the FBSM powers by injecting an additional power degree of freedom, resulting in a smaller FBSM capacitor voltage ripple, while keeping the maximum AC output voltage for a given fundamental frequency component of the arm voltage reference. Accordingly, a control strategy was developed, based on non-sinusoidal ZSVI, and SHCI is proposed for further improving the performance of the FBSM-MMC. The proposed non-sinusoidal ZSVI contains a higher sinusoidal third-order harmonic component than that of pure sinusoidal third-order voltage injection (THVI) when operating under the same maximum AC output voltage. By implementing this solution, a smaller amplitude of the injected second-order harmonic current can be achieved, producing a lower power loss in the FBSM-MMC. Considering the proposed solution, the relationship of the arm powers and FBSM capacitor voltages are also discussed. Finally, the simulation results and experimental results are presented to verify the effectiveness of the theoretical analysis of the proposed method.

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Xia, Siyi, Yunfeng Li, Hangyu Wei, and Yu Zhang. "Reliability analysis of half-/full-bridge hybrid MMCs based on submodule correlation." IET Conference Proceedings 2024, no. 33 (2025): 1250–54. https://doi.org/10.1049/icp.2025.0701.

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Sheik, Rasheed, Kumar Ch.Pavan, and Shankar M.Mani. "Design of Full-Bridge Modular Multilevel Converter with Low Energy Storage Requirements for HVdc Transmission System with Fuzzy Inference System." International Journal of Engineering and Advanced Technology (IJEAT) 10, no. 2 (2020): 132–40. https://doi.org/10.35940/ijeat.B2067.1210220.

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This paper proposes a hierarchical Fuzzy Interface System (FIS) Predicated control architecture designed for an arbitrary high voltage multi terminal dc (MTDC) network. Modular multilevel converter (MMC)s a well-proved circuit topology in voltage-source converter-based high voltage direct current (VSC-HVdc) transmission systems. As is known, the conventional half-bridge submodule (HBSM)-based MMC-HVdc s not suitable for overhead line transmission applications. In addition, high energy storage requirements, .e., large capacitance is nevitable. The conventional design of the full-bridge submodule (FBSM)-based MMC usually does not utilize the negative voltage state of FBSM in normal operation. Considering the same dc voltage as with the HBSM case and utilizing the negative voltage state of the FBSM, this paper presents the design method of the power transmission capability of a single FBSM. Meanwhile, an optimized energy storage capacitance design method of the FBSM is proposed. With this method, the capacitance of FBSM can be reduced significantly. The correctness and effectiveness of the proposed method is verified by the simulation of a±160kVVSC-HVdc MMC and the comparison results of the dc short fault blocking and ride through capability are also provided.

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Damian, Ioan-Cătălin, Mircea Eremia, and Lucian Toma. "Fault Simulations in a Multiterminal High Voltage DC Network with Modular Multilevel Converters Using Full-Bridge Submodules." Energies 14, no. 6 (2021): 1653. http://dx.doi.org/10.3390/en14061653.

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The concept of high-voltage DC transmission using a multiterminal configuration is presently a central topic of research and investment due to rekindled interest in renewable energy resource integration. Moreover, great attention is given to fault analysis, which leads to the necessity of developing proper tools that enable proficient dynamic simulations. This paper leverages models and control system design techniques and demonstrates their appropriateness for scenarios in which faults are applied. Furthermore, this paper relies on full-bridge submodule topologies in order to underline the increase in resilience that such a configuration brings to the multiterminal DC network, after an unexpected disturbance. Therefore, strong focus is given to fault response, considering that converters use a full-bridge topology and that overhead power lines connect the terminals.

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Marca, Ygor Pereira, Maurice G. L. Roes, Cornelis G. E. Wijnands, Jorge L. Duarte, and Henk Huisman. "Single-Stage MV-Connected Charger Using an Ac/Ac Modular Multilevel Converter." Energies 17, no. 12 (2024): 2998. http://dx.doi.org/10.3390/en17122998.

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Modular multilevel converters with non-sinusoidal ac voltage output can reduce cost and volume in medium-voltage-connected electric vehicle battery charging applications. The use of full-bridge submodules in such converters enables single-stage ac/ac voltage conversion, allowing a medium-voltage grid to be directly connected to a medium-frequency isolation transformer. The application of a square wave voltage at the medium-frequency transformer’s single-phase port enhances the converter’s efficiency and power density in comparison to a sinusoidal voltage. This paper presents the analysis and modelling of a modular multilevel converter, comparing its operation with sinusoidal and square wave output voltages. A single control scheme for both output voltage waveforms is proposed for the three-phase and single-phase ac currents, circulating currents, and the energy stored in the submodule capacitors. The control strategy of the three-phase and single-phase port currents is verified through simulation and experiments using a scaled-down prototype, thereby validating its suitability for high-power bidirectional battery chargers.

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Wei, Xinwei, Xiaonan Zhu, Wenyuan Zhang, et al. "Multilayer Model Predictive Control for a Voltage Mode Digital Power Amplifier." Electronics 10, no. 14 (2021): 1699. http://dx.doi.org/10.3390/electronics10141699.

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The application of the finite control set model predictive control to cascaded inverters is severely limited by its computational complexity. In this paper, a load observer based multilayer model predictive control is proposed for the voltage mode digital power amplifier employing cascaded full-bridge neutral point clamped inverter, which can avoid the use of load current sensor and greatly reduce the controller computation without affecting its dynamic performance. The discrete mathematical model of the voltage mode digital power amplifier employing cascaded full-bridge neutral point clamped inverter is established with filter inductor current and filter capacitor voltage as state variables. A load current observer is designed based on this to avoid the use of load current observer. Based on the discrete model and the observed load current, the upper layer of the multilayer model predictive control determines the optimal level that minimizes the cost function. The middle layer allocates the optimal level to each submodule in order to achieve capacitor voltage balancing. The lower layer determines the switching state of each submodule in order to reduce switching actions. Finally, the experimental results based on the designed nine-level prototype show that the develop multilayer model predictive control lead to acceptable steady state, dynamic and robust performance, with only 1.37% of the run time of the traditional model predictive control.

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Heinig, Stefanie, Keijo Jacobs, Kalle Ilves, et al. "Implications of Capacitor Voltage Imbalance on the Operation of the Semi-Full-Bridge Submodule." IEEE Transactions on Power Electronics 34, no. 10 (2019): 9520–35. http://dx.doi.org/10.1109/tpel.2018.2890622.

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Sakib, Munif Nazmus, Sahar Pirooz Azad, and Mehrdad Kazerani. "A Critical Review of Modular Multilevel Converter Configurations and Submodule Topologies from DC Fault Blocking and Ride-Through Capabilities Viewpoints for HVDC Applications." Energies 15, no. 11 (2022): 4176. http://dx.doi.org/10.3390/en15114176.

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Modular multilevel converters (MMCs) based on half-bridge submodules (HBSMs) are unable to prevent the AC side contribution to DC side fault currents, thus necessitating circuit breakers (CBs) for protection. A solution to this problem is using submodules (SMs) that are capable of blocking the flow of current from the AC grid to feed the DC side fault. The full-bridge submodule (FBSM) is one type of fault blocking SM where the presence of two extra switches ensures that in the event of a DC fault, the reverse voltage from the FBSM capacitor is placed in the path of the AC side current feeding the DC side fault through the antiparallel diodes. However, the additional semiconductor switches in the FBSMs increase the converter cost, complexity, and losses. Several SM configurations have been proposed in recent years that provide DC fault blocking capability with lower losses and device counts than those of FBSMs. Besides, many of the proposed hybrid converter configurations that combine different topologies to optimize converter performance are also capable of providing DC fault blocking. Furthermore, certain SM topologies are capable of riding through DC faults by remaining deblocked and operating in static synchronous compensator (STATCOM) mode to provide reactive power support to the AC grid. In this paper, noteworthy SM and MMC configurations capable of DC fault blocking and ride-through are reviewed and compared in terms of component requirements, semiconductor losses, and DC fault handing capability. The review also includes a discussion on control strategies for MMC arm/leg energy balancing during STATCOM operation.

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Kontos, E., G. Tsolaridis, R. Teodorescu, and P. Bauer. "Full-bridge MMC DC fault ride-through and STATCOM operation in multi-terminal HVDC grids." Bulletin of the Polish Academy of Sciences Technical Sciences 65, no. 5 (2017): 653–62. http://dx.doi.org/10.1515/bpasts-2017-0070.

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Abstract This paper investigates a control structure to enhance the DC fault ride-through capability of a full-bridge modular multilevel converter (MMC) station, while ensuring a stable controlled operation as a STATCOM during DC faults without the need for fault isolation. Taking advantage of the switching states of a full-bridge submodule, a DC current controller is proposed, which provides the DC voltage reference for the modulation when a DC fault is detected. By changing the outer controllers strategy from DC voltage or active power control to converter energy control during a fault, the decoupling of the converter operation from the DC side dynamics is realized. In this paper, the focus is on the control methodology at all times of operation and the evaluation of the STATCOM control during a fault. To this end, extensive simulations were performed on a three-terminal high voltage direct current (HVDC) grid in radial configuration and a pole-to-pole DC fault case was investigated. The results showed that the AC voltage and current were controlled within limits at all times, while the full-bridge MMC was able to provide reactive power support to the AC grid. Moreover, using the proposed control methodology, the transients at the operation transition points between STATCOM and inverter/rectifier operation were minimized and the stations were able to safely ride through the fault.

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Fang, Xiongfeng, Gen Li, Canfeng Chen, Dongyu Wang, Jian Xiong, and Kai Zhang. "An Energy Absorbing Method for Hybrid MMCs to Avoid Full-Bridge Submodule Overvoltage During DC Fault Blocking." IEEE Transactions on Power Electronics 37, no. 5 (2022): 4947–51. http://dx.doi.org/10.1109/tpel.2021.3130766.

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Elserougi, Ahmed A., Ibrahim Abdelsalam, Ahmed M. Massoud, and Shehab Ahmed. "A Full-Bridge Submodule-Based Modular Unipolar/Bipolar High-Voltage Pulse Generator With Sequential Charging of Capacitors." IEEE Transactions on Plasma Science 45, no. 1 (2017): 91–99. http://dx.doi.org/10.1109/tps.2016.2633489.

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Liu, Junyi, Yanfang Fan, Junjie Hou, and Xueyan Bai. "Reliability Evaluation of DC/DC Converter in Direct Current Collection System of Wind Farm Considering the Influence of Control Strategy." Processes 11, no. 10 (2023): 2825. http://dx.doi.org/10.3390/pr11102825.

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The DC collection system of wind farms can effectively solve the problems of harmonic resonance and reactive power transmission in large-scale wind power AC collection systems, and has broad development prospects. The DC/DC converter is critical equipment in the wind farm DC collection system, and its reliability is related to the entire collection system’s safe and stable operation. The reliability of DC/DC converters is affected by factors such as system operating conditions and control strategies. Based on this, a reliability evaluation model for boost full-bridge isolated (BFBIC) DC/DC converters is proposed from the device level to the submodule level and then to the equipment level, incorporating operating conditions and control strategies into reliability analysis. Firstly, in device-level reliability modeling, the impact of DC/DC converter operating conditions and control strategies on insulated gate bipolar transistor (IGBT) module losses and junction temperature fluctuations are considered. Secondly, fault tree analysis (FTA) is used to establish the reliability model of the BFBIC submodule and DC/DC converter. In the end, we verify the effectiveness of the proposed model through a numerical example, and provide solid data support for analyzing the reliability of the wind farm DC collection system.

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Barros, Luis A. M., António P. Martins, and José Gabriel Pinto. "A Comprehensive Review on Modular Multilevel Converters, Submodule Topologies, and Modulation Techniques." Energies 15, no. 3 (2022): 1078. http://dx.doi.org/10.3390/en15031078.

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The concept of the modular multilevel converter (MLC) has been raising interest in research in order to improve their performance and applicability. The potential of an MLC is enormous, with a great focus on medium- and high-voltage applications, such as solar photovoltaic and wind farms, electrified railway systems, or power distribution systems. This concept makes it possible to overcome the limitation of the semiconductors blocking voltages, presenting advantageous characteristics. However, the complexity of implementation and control presents added challenges. Thus, this paper aims to contribute with a critical and comparative analysis of the state-of-the-art aspects of this concept in order to maximize its potential. In this paper, different power electronics converter topologies that can be integrated into the MLC concept are presented, highlighting the advantages and disadvantages of each topology. Nevertheless, different modulation techniques used in an MLC are also presented and analyzed. Computational simulations of all the modulation techniques under analysis were developed, based on four cascaded full-bridge topologies. Considering the simulation results, a comparative analysis was possible to make regarding the symmetry of the synthesized waveforms, the harmonic content, and the power distribution in each submodule constituting the MLC.

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Ruge, Dorte, Heather Dawn Johannesen, Frøydis Nordgård Vik, Zdenek Janík, and Stojan Kostanjevec. "Introduction." Futures of Education, Culture and Nature - Learning to Become 2, no. 3 (2024): 1–10. https://doi.org/10.7146/fecun.v2i3.152506.

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The aim of the SustainComp project was to bridge the gap between sector-divided, discipline-embedded national curricula in education and to address the current need for competence-based, interdisciplinary, transformative, and internationalized Higher Education (HE) that is in congruence with the European Council Erasmus+ program and the 21st Century learning goals. Four HE partners – UCL University College in Denmark, University of Agder in Norway, University of Ljubljana, Slovenia, and Masaryk University, Czech Republic - set out to develop a 10 ECTS SustainComp Curriculum, each partner contributing to the aims with a 2,5 ECTS submodule as part of the SustainComp curriculum. The development of the 10 ECTS SustainComp curriculum was guided by Design Based Research (DBR) approach, enabling the four HEs to test in practice and adjust the curriculum in the pre-pilot phase in April 2023 and the full-scale pilot in October-December 2023. See fig 1

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Abdelsalam, Ibrahim, Mohamed A. Elgenedy, Shehab Ahmed, and Barry W. Williams. "Full-Bridge Modular Multilevel Submodule-Based High-Voltage Bipolar Pulse Generator With Low-Voltage DC, Input for Pulsed Electric Field Applications." IEEE Transactions on Plasma Science 45, no. 10 (2017): 2857–64. http://dx.doi.org/10.1109/tps.2017.2743822.

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Sakib, Munif Nazmus, Sahar Pirooz Azad, and Mehrdad Kazerani. "Fast DC Fault Current Suppression and Fault Ride-Through in Full-Bridge MMCs via Reverse SM Capacitor Discharge." Energies 15, no. 13 (2022): 4595. http://dx.doi.org/10.3390/en15134595.

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In the event of a DC side fault in modular multilevel converters (MMCs), the fault current contributions are initially made by submodule (SM) capacitor discharge, which occurs before the fault is detected, followed by the AC side contribution to the DC side fault. While the AC side currents can be regulated using fault blocking SMs, the initial discharge of the SM capacitors results in high DC fault currents, which can take several milliseconds to be brought under control. This paper presents a method to actively control the rate of rise of the DC fault current by regulating the discharge of SM capacitors and accelerating the suppression of fault current oscillations during fault ride-through (FRT) in a full-bridge (FB)-MMC system. In the proposed method, the discharge direction of the FBSM capacitors is reversed following the detection of a DC side fault, which leads to a reversal in the fault current direction and a fast drop-off towards the zero-crossing. Immediately after the zero-crossing of the DC fault current, the DC fault is cleared by adjusting the arm voltage references and operating the MMC as a static synchronous compensator (STATCOM) to provide voltage support to the AC grid. The proposed control scheme provides faster fault current suppression, more effective SM capacitor voltage regulation, low AC side and MMC arm current transient peaks, and an overall superior DC-FRT performance compared to methods in which the conventional fault ride-through operation is initiated immediately upon DC fault detection.

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Firas, Abdul-Hadi Salih, and Kahawish Hassan Turki. "Capacitor voltages balancing method for buck modular DC/DC converter." International Journal of Power Electronics and Drive Systems 13, no. 4 (2022): 2277~2285. https://doi.org/10.11591/ijpeds.v13.i4.pp2277-2285.

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The most critical problem of the modular DC-DC converter (MDCC) is the voltage balancing of the submodule (SM) capacitors, the MDCC with stepped 2-level modulation has been developed and presents a good solution, however, this type of modulation has many restrictions when there is a wide range of capacitance tolerance of the SM capacitors that results inaccurate capacitor voltages balancing. To solve this problem, this paper discusses a proposed method of capacitor voltage balancing. Compared with stepped 2-level modulation, the voltage balancing method using modified duty cycle modulation offers the merits: i) reduction in output voltage and SM capacitor voltages overshoot during dynamic operation and improvement in the time response of the system and; ii) accurate voltage balancing over wide range of capacitance tolerance of each SM capacitor; and iii) the sorting algorithm replaced with modified duty cycle modulation method for the SM capacitor voltages balancing which reduces the computation burden. The proposed method ensures a stable voltage balancing, improves the time response of the system, and decreases the voltage and current overshoot during the dynamic response compared with prior art of MDCCs, where the stepped 2-level modulation is adopted. An analytical simulation of the MDCC is presented using MATLAB/Simulink to explain the operation.

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Kim, Jae-Myeong, Geum-Seop Song, and Jae-Jung Jung. "Zero-Sequence Voltage Injection Method for DC Capacitor Voltage Balancing of Wye-Connected CHB Converter under Unbalanced Grid and Load Conditions." Energies 14, no. 4 (2021): 1019. http://dx.doi.org/10.3390/en14041019.

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Leg capacitor energy balancing control is one of the crucial issues for stable operation of a cascaded H-bridge (CHB) converter. Because this topology inherently consists of numerous submodule cells with DC capacitors, the cell voltages and leg capacitor energy instantaneously fluctuate depending on operation sequence of the CHB converter. In general, a wye-connected CHB-converter-based static synchronous compensator (STATCOM) utilizes a zero-sequence voltage component for leg capacitor energy balancing. In this paper, to improve the dynamics of leg energy balancing control, a feedforward calculation method of the zero-sequence voltage injection is proposed. The feedforward term can be instantaneously calculated by using the information from the measured leg voltages and leg currents, and the method ensures successful regulation of the leg energy balance even under unbalanced grid and load conditions. Moreover, the verification of the proposed method is supported by the mathematical vector theorems. A 50MVA full-scale wye-connected CHB–STATCOM system simulation was performed to verify the proposed feedforward calculation method considering unbalanced grid as well as unbalanced load conditions.

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Rodrigues, Nuno, Jose Cunha, Vitor Monteiro, and Joao L. Afonso. "Development and Experimental Validation of a Reduced-Scale Single-Phase Modular Multilevel Converter Applied to a Railway Static Converter." Electronics 12, no. 6 (2023): 1367. http://dx.doi.org/10.3390/electronics12061367.

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With special emphasis in recent years, an increase has been verified not only in demand but also in the price of electricity, arising the need to develop more reliable and efficient electrical energy conversion systems. In this context, emerges the utilization of the modular multilevel converter (MMC) based on submodules. The key to the MMC is modularity, which allows the converter to reach higher performance levels, improving the voltage and current output signals of the converter, in a compact solution. The modularity concept allows the increase of the operation voltage using submodules in series, and the increase of the operating current using submodules in parallel. Additionally, in the event of a submodule malfunction, the converter can be reconfigured and continue the operation, albeit at a lower power level. Due to its versatility, the MMC can be used in a variety of applications, such as HVDC power transmission systems, solid-state transformers, renewable energy interfaces, and more recently, railway power systems. In this context, this paper focuses on the development and experimental validation of a single-phase MMC based on the use of half-bridge submodules applied to a railway static converter, where the main focus lies on the AC side control. The control algorithms are fully described for a single-phase MMC reduced-scale prototype implemented (500 W, 230 V–50 Hz, 200 VDC), connecting two submodules in series in the upper arm, two submodules also in series in the lower arm, the respective driver and command circuits, sensing and signal conditioning circuits, as well as a digital control platform recurring to the DSP TMS320F28379D. Experimental results were obtained to validate each submodule individually, and, later, to verify the operation of the MMC with the set of four submodules.

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Li, Rui, Lie Xu, Lujie Yu, and Liangzhong Yao. "A Hybrid Modular Multilevel Converter With Reduced Full-Bridge Submodules." IEEE Transactions on Power Delivery 35, no. 4 (2020): 1876–85. http://dx.doi.org/10.1109/tpwrd.2019.2956265.

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Zhou, Fayun, Xinxing Xiang, Fujun Ma, Yichao Wang, Fangyuan Zhou, and Peng Peng. "An Improved Phase-Disposition Pulse Width Modulation Method for Hybrid Modular Multilevel Converter." Energies 16, no. 3 (2023): 1192. http://dx.doi.org/10.3390/en16031192.

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The hybrid modular multilevel converter (MMC) consisting of half-bridge submodules (HBSMs) and full-bridge submodules (FBSMs) is a promising solution for overhead lines high-voltage direct current systems (HVDC) due to the advantages of direct current short circuit fault ride-through (DC-FRT) capability. This paper proposes an improved phase-disposition pulse width modulation (PDPWM) method for the hybrid modular multilevel converter. The number of carriers can be reduced from 3N (N is the number of submodules in each arm) to 6. The theoretical harmonic analysis of the improved PDPWM method for hybrid MMC is performed by using double Fourier integral analysis. The influence of three carrier displacement angles between HBSMs and FBSMs in the upper and lower arms on harmonic characteristics is investigated. The output voltage harmonics minimization PDPWM scheme and circulating current harmonics cancellation PDPWM scheme can be achieved by selecting the optimum carrier displacement angles, respectively. The proposed method for hybrid MMC is verified by the simulation and experimental results.

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Xu, Yuzhe, Zheren Zhang, and Zheng Xu. "Design and DC fault clearance of modified hybrid MMC with low proportion of full‐bridge submodules." IET Generation, Transmission & Distribution 15, no. 15 (2021): 2203–14. http://dx.doi.org/10.1049/gtd2.12170.

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He, Liqun, Kai Zhang, Jian Xiong, Shengfang Fan, and Yaosuo Xue. "Low-Frequency Ripple Suppression for Medium-Voltage Drives Using Modular Multilevel Converter With Full-Bridge Submodules." IEEE Journal of Emerging and Selected Topics in Power Electronics 4, no. 2 (2016): 657–67. http://dx.doi.org/10.1109/jestpe.2015.2477433.

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Wang, Kailun, Qiang Song, and Shukai Xu. "Analysis and Design of the Energy Storage Requirement of Hybrid Modular Multilevel Converters Using Numerical Integration and Iterative Solution." Energies 15, no. 3 (2022): 1225. http://dx.doi.org/10.3390/en15031225.

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Increasing the modulation index by utilizing the negative voltage states of full-bridge submodules (FBSMs) can greatly reduce capacitor usage of modular multilevel converters (MMCs), thereby optimizing the cost and volume. The hybrid MMC is composed of half-bridge submodules (HBSMs) and FBSMs, and the capacitor voltages of the two types of submodules (SMs) have different shapes as long as negative voltage states exist. This condition greatly complicates the analysis and design of the energy storage requirement of the hybrid MMC, which utilizes the negative voltage states of FBSMs to boost the AC voltage. A numerical calculation method for solving the capacitor voltages and designing the capacitances of FBSMs and HBSMs is proposed in order to accurately determine the minimum energy storage requirement considering the difference between the energy variations in FBSMs and HBSMs. In the numerical calculation, the energy storage and voltage of the arm are decomposed into FBSM and HBSM parts. According to the physical switching process, the output voltages of FBSM and HBSM parts are determined separately. The one-cycle waveforms of the capacitor voltages are then obtained by numerical integration of the power flows in FBSM and HBSM parts. An iterative solution procedure and the termination criterion that can ensure the accuracy of the obtained one-cycle waveforms are also proposed. Using the numerical integration and iterative solution procedure as the kernel algorithm, the proposed method can accurately analyze the capacitor voltages of the FBSMs and HBSMs and determine the minimum energy storage requirement of the hybrid MMC. Furthermore, the proposed method is applicable for various operating working conditions and various proportions of FBSMs. The simulation results verify the feasibility and accuracy of the analysis and design method.

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Wang, Yunzhi, Fei Sun, Jun Chen, Huafeng Cai, and Shen Gao. "Novel Series-Parallel Phase-Shifted Full-Bridge Converters with Auxiliary LC Networks to Achieve Wide Lagging-Leg ZVS Range." Electronics 13, no. 7 (2024): 1311. http://dx.doi.org/10.3390/electronics13071311.

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Under light load conditions, the phase-shifted full-bridge (PSFB) converter often has difficulty in realizing the zero-voltage switching (ZVS) of the lagging-leg by relying on the energy of its resonant inductor; however, for the series-parallel PSFB converter applied in high-power applications, the lagging-leg still has the problem of difficult realization of ZVS. Based on this, the paper analyzes the reasons why the series-parallel PSFB converter has difficulty in achieving ZVS for the lagging-leg under light and heavy loads. Under interleaved control, the ZVS of the lagging-leg over the full load range is realized by adding an auxiliary LC branch at the midpoint of the lagging-leg of both submodules. Based on the double-bridge input-parallel-output-series (IPOS) PSFB converter, analyzing the working principle of the circuit after adding the auxiliary LC branch and extending it to the series-parallel PSFB converter. The design requirements of the LC auxiliary branch of the dual-bridge series-parallel PSFB converter are given and the effects of the LC auxiliary branch on the module operating state and device stress are analyzed. On this basis, an extension is carried out to give the working principle and design method of the auxiliary LC branch of the N-bridge series-parallel PSFB converter. Finally, a 100 kW Matlab/Simulink simulation model verifies the superior performance of the proposed LC auxiliary branch to realize the lagging-leg ZVS of the series-parallel PSFB converter under light and heavy loads and achieves a 1.09% peak efficiency improvement at rated load.

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Zhang, Jianbin, Quanrui Hao, and Dong Li. "Hardware Platform Construction of Hybrid Modular Multilevel Converter Purely Based on FPGA Controller." Journal of Physics: Conference Series 2401, no. 1 (2022): 012047. http://dx.doi.org/10.1088/1742-6596/2401/1/012047.

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Abstract The modular multilevel converter (MMC) hardware platform is of great significance to the research of control and protection before engineering operation. In practical engineering, each bridge arm is composed of many submodules (SMs) cascaded, which brings significant challenges to the research. In this paper, a controller based on a field programmable gate array (FPGA) is designed for hybrid MMC, and a hardware platform is built on this basis. The platform fully uses the parallel characteristics of FPGA to improve the calculation speed of the controller. It optimizes the SM capacitor voltage sorting method to shorten the sorting time significantly. The stability experiment verifies that the hardware platform can be applied to the research of hybrid MMC.

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Suo, Zhiwen, Gengyin Li, Lie Xu, Rui Li, Weisheng Wang, and Yongning Chi. "Hybrid modular multilevel converter based multi‐terminal DC/DC converter with minimised full‐bridge submodules ratio considering DC fault isolation." IET Renewable Power Generation 10, no. 10 (2016): 1587–96. http://dx.doi.org/10.1049/iet-rpg.2016.0281.

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Nasr Esfahani, Fatemeh, Ahmed Darwish, and Xiandong Ma. "Design and Control of a Modular Integrated On-Board Battery Charger for EV Applications with Cell Balancing." Batteries 10, no. 1 (2024): 17. http://dx.doi.org/10.3390/batteries10010017.

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This paper presents operation and control systems for a new modular on-board charger (OBC) based on a SEPIC converter (MSOBC) for electric vehicle (EV) applications. The MSOBC aims to modularise the battery units in the energy storage system of the EV to provide better safety and improved operation. This is mainly achieved by reducing the voltage of the battery packs without sacrificing the performance required by the HV system. The proposed MSOBC is an integrated OBC which can operate the EV during traction and braking, as well as charge the battery units. The MSOBC is composed of several submodules consisting of a full-bridge voltage source converter connected on the ac side and SEPIC converter installed on the battery side. The SEPIC converter controls the battery segments with a continuous current because it has an input inductor which can smooth the battery’s currents without the need for large electrolytic capacitors. The isolated version of the SEPIC converter is employed to enhance the system’s safety by providing galvanic isolation between the batteries and the ac output side. This paper presents the necessary control loops to ensure the optimal operation of the EV with the MSOBC in terms of charge and temperature balance without disturbing the required modes of operation. The mathematical analyses in this paper are validated using a full-scale EV controlled by TMS320F28335 DSP.

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Terlizzi, Cristina, Antonio Magnanimo, Francesco Santoro, and Stefano Bifaretti. "Development of a Scalable MMC Pulsed Power Supply through HIL Methodology." Energies 16, no. 10 (2023): 4106. http://dx.doi.org/10.3390/en16104106.

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Nuclear fusion experiments are becoming one of the most interesting focuses of research, given the hope of generating programmable, safe, and green energy. Among them, ASDEX (axially symmetric divertor experiment) upgrade has been operating at the Max Planck Institute for Plasma Physics (IPP) research center since 1991. To ignite and confine the plasma, several coils must be supplied through controllable high-current pulsed power supplies. The toroidal field magnets are here considered and a modular multilevel converter (MMC)-like system was designed and tested thanks to a small-scale prototype in previous works. The MMC-like topology, consisting of full-bridge submodules (SMs) with IGBTs and supercapacitor and exploitable also for other industrial applications, was chosen because of its modularity, redundancy, fault tolerance, and large amount of stored energy. The prototype, made of four SMs, was necessary to highlight critical key points in the design process. However, its scalability must be further tested before building a full-scale power supply, meant to reach almost 2400 SMs to guarantee the energy required by the load. This paper aims at validating hardware-in-the-loop (a powerful, safe, and relatively inexpensive real-time simulation environment that enables testing with real control boards) as a useful technology for power supply scalability studies and not only for control strategy tests. The results obtained previously from the prototype will allow us to finally increase the number of SMs and test the MMC-like scalability.

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Sun, Fei, Jun Chen, Xinchun Lin, and Dongchu Liao. "Analysis and Suppression of Rectifier Diode Voltage Oscillation Mechanism in IPOS High-Power PSFB Converters." Electronics 12, no. 13 (2023): 2871. http://dx.doi.org/10.3390/electronics12132871.

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Parasitic oscillations in the rectifier diode voltage of phase-shifted-full-bridge (PSFB) converters limit their application in high-voltage and high-power situations. The conventional analysis method for parasitic oscillation in rectifier diode voltage in PSFB converters treats the filter inductor as a constant current source and fails to consider the impact of changes in filter inductor current on the rectifier diode’s parasitic oscillation. Consequently, this approach does not apply when analyzing the rectifier diode voltage’s parasitic oscillations in high-power PSFB converters employing an input-parallel output-series (IPOS) configuration with interleaved drive. This research paper introduces an innovative equivalent circuit model for analyzing the parasitic oscillations of rectifier diode voltage in IPOS high-power PSFB converters. The model takes into account the mutual influence of rectifier diode voltage oscillations between submodules under interleaved control, considering the influence of changes in filter inductor current on rectifier diode parasitic oscillation. Based on the circuit model, we explain the mechanism of multiple oscillations of the rectifier diode voltage and the reason for the high peak of the first oscillation. Consequently, the interplay of rectifier diode voltage oscillations in IPOS high-power k-module PSFB converters under interleaved control is analyzed. To mitigate the adverse effects of rectifier diode voltage parasitic oscillation, a buffering strategy involving the connection of a resistor capacitor diode (RCD) circuit in parallel after the rectifier bridge is adopted, considering the structure of the IPOS high-power PSFB converter. The study provides a detailed analysis of the circuit’s operation mechanism upon incorporating the RCD buffer circuit and establishes the relationship between buffer capacitance, resistance, and spike voltage. Furthermore, a design method for buffer capacitors and discharge resistors in buffer circuits is presented. Finally, a 100 kW prototype is tested to verify the rectifier diode voltage oscillation mechanism of the IPOS high-power PSFB converter and the rationality of the buffer capacitor and discharge resistor design method under the interleaved drive approach.

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Liu, Yiqi, Laicheng Yin, Zhaoyu Duan, Zhenjie Li, Mingfei Ban, and Jiawei Zhang. "A low‐cost MMC submodule topology with fast DC fault handling capability." IET Power Electronics 18, no. 1 (2025). https://doi.org/10.1049/pel2.12846.

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AbstractWith the continuous development of new energy technologies and the widespread application of high voltage direct current transmission technology, the use of modular multilevel converters (MMC) has significantly increased. Traditional MMCs, composed of half‐bridge submodules, lack fault handling capabilities, and cannot block fault currents on the DC side, thus compromising the stability of transmission systems. Therefore, this study proposes a low‐cost improved MMC submodule topology based on the dual‐bidirectional switch submodule (DBSSM) and provides an analysis and description of its structure and operating principles. The proposed DBSSM structure can output five voltage levels: 0, ± Uc, and ±2 Uc. Compared to the full‐bridge submodule topology, which achieves the same effect, the DBSSM reduces the number of IGBTs by half, significantly lowering hardware costs. A simulation model with a DC side voltage of 80 kV was built using MATLAB/Simulink to verify this topology. In the 80 kV scenario, the proposed DBSSM achieved DC fault ride‐through within 3 ms, doubling the speed compared to the full‐bridge submodule. Finally, hardware‐in‐the‐loop testing was performed using the dSPACE1202 and relevant hardware circuits, confirming the feasibility of the proposed structure.

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Diwan, Anuja Prashant Prashant, N. Booma Nagarajan, and M. Venmathi. "Comparative Analysis of Submodules and Design of Seventeen-Level Modular Multilevel Converter Using A Five-level Submodule Block." Engineering Research Express, October 15, 2024. http://dx.doi.org/10.1088/2631-8695/ad8726.

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Abstract Multilevel inverters and various modulation techniques have been proven to be the best solutions to overcome all the limitations of conventional two- or three-level voltage source inverters. In recent years, among all topologies, modular multilevel converter (MMC) has advantages like low total harmonic distortion (THD), reduced filter requirement, fault-tolerant operation, scalability, modularity, transformerless operation, etc. The main application of MMC is found in high-voltage DC transmission (HVDC). This study describes and analyses the performance of two distinct MMC submodule (SM) topologies: the Half Bridge submodule (HBSM) and the Full Bridge submodule (FBSM). Switching pattern is simpler in HBSM topology but it has the disadvantage that it does not have DC fault current blocking capability. Whereas FBSM not only inherently can block the DC fault current but also has advantages like reduced volume of MMC and better performance. Further, having the capability to produce three voltage levels, it can be operated in boost mode. Also, by using a proper switching pattern, MMC can be designed to generate a various number of output levels by using the same five-level submodule block. Out of which 17 level MMC gives the best output. The MATLAB-Simulink model is used to simulate the circuit, and the findings are confirmed for a 17-level output voltage.

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Song, Yonghui, Yongjie Luo, and Xiaofu Xiong. "Loss distribution analysis and accurate calculation method for bulk-power MMC." Protection and Control of Modern Power Systems 8, no. 1 (2023). http://dx.doi.org/10.1186/s41601-023-00313-x.

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AbstractAccurate evaluation of power losses in a modular multilevel converter (MMC) is very important for circuit component selection, cooling system design, and reliability analysis of power transmission systems. However, the existing converter valve loss calculation methods using the nearest level modulation (NLM) method and the traditional sorting-based capacitor voltage balancing strategy are inaccurate since the submodule (SM) switching logics in the MMC arms are uncertain. To solve this problem, the switching principle of the SMs in the sorting-based voltage balancing strategy is analyzed. An accurate MMC power loss calculation method based on the analysis of loss distribution of various SM topologies, including half-bridge submodule (HBSM), full-bridge submodule (FBSM) and clamp double submodule (CDSM), is proposed in this paper. The method can accurately calculate the losses caused by the extra switching actions during the capacitor voltage balancing process, thus greatly increasing the calculation accuracy of switching losses compared with existing methods. Simulation results based on a practical ± 350 kV/1000 MW MMC-HVDC system with variety of MMC topologies with different voltage balancing strategies demonstrate the effectiveness of the proposed method.

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Zhou, Yiyuan, Liang Qin, Shiqi Yang, Qing Wang, and Kaipei Liu. "A selection principle of submodule switching state vectors for switching frequency reduction in voltage self‐balancing half‐bridge modular multilevel converters." IET Power Electronics, November 12, 2023. http://dx.doi.org/10.1049/pel2.12606.

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AbstractThe problem of submodule switching frequency reduction in half‐bridge modular multilevel converters (HB‐MMCs) with capacitor voltage self‐balancing control is considered and explored in this paper. A selection principle of submodule switching state vectors is proposed based on the voltage self‐balancing switching state matrix, aiming to lower submodule switching frequency and device losses. The relationship between system stability and submodule switching signals is revealed according to the capacitor voltage self‐balancing characteristics, and the full‐rank constraints on the voltage self‐balancing switching state matrix are proposed. Considering the tradeoff between switching loss and capacitor voltage fluctuation, the evaluation indexes of voltage self‐balancing control effect are determined. The selection principle of submodule switching state vectors and the optimized construction method of switching state matrix are presented. Voltage self‐balancing HB‐MMC models are built in MATLAB/Simulink, and it is verified that the submodule switching state vector selection principle proposed in this study can effectively reduce switching frequency while meeting the evaluation requirements of practical engineering projects, so as to achieve the balance between switching loss and steady‐state capacitor voltage fluctuation.

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Xu, Yutao, Zhukui Tan, Jikai Li, Qihui Feng, and Zhuang Wu. "A lightweight MMC topology with recombined half‐bridge submodules for DC fault ride‐through." IET Generation, Transmission & Distribution, November 4, 2024. http://dx.doi.org/10.1049/gtd2.13282.

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AbstractThe lightweight of modular multilevel converter (MMC) and the DC faults ride‐through ability are main challenges for MMC‐high voltage direct current (HVDC) transmission systems. By introducing the concept of time‐division multiplexing, an arm multiplexing MMC (AM‐MMC) topology with high utilization of submodules is presented to reduce the weight and volume of MMC. In order to block the DC side fault current, this paper proposes a novel submodule in AM‐MMC, instead of using full‐bridge submodules. The proposed recombined half‐bridge submodules of AM‐MMC (RHAM‐MMC) contains four half‐bridge submodules and an IGBT with reverse parallel diodes. The topology and operating principle of RHAM‐MMC are introduced in detail. The time‐division multiplexing of middle arms between upper and lower arms is achieved by introducing arm selection switches. Thus, a new type of arm switch and switching method is designed based on the switch state. The DC faults ride‐through strategy is carried out based on its DC fault characteristic analysis. In addition, the economy analysis is conducted on the switching loss and operating loss of RHAM‐MMC. Compared with the fault ride‐through capability of other sub‐modules (SMs), RHAM‐MMC performs better in terms of investment cost and device losses. The simulation results based on MATLAB/Simulink reveal that RHAM‐MMC can achieve the DC side fault ride‐through and show effectiveness of the DC fault ride‐through control strategy.

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Shu, Dewu, Venkata Dinavahi, Xiaorong Xie, and Qirong Jiang. "Shifted Frequency Modeling of Hybrid Modular Multilevel Converters for Simulation of MTDC Grid." June 1, 2018. https://doi.org/10.5281/zenodo.7678001.

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When investigating voltage and current stresses in critical main circuit components during faults of the converter, a detailed equivalent model capable of representing the balancing control strategies of the capacitor voltages on the submodule level, along with blocking and delocking, is always necessary. Among previously proposed equivalent models of the modular multilevel converter (MMC), only submodule averaged models (SAMs) can capture interested inner dynamics inside each arm. However, the simulation accuracy of SAMs is not always satisfactory, especially when the time step is larger than 10 μs. In order to further improve the simulation accuracy with guaranteed simulation efficiency, the shifted frequency modeling of the half- and full-bridge hybrid MMC is proposed in this paper. Therein, each submodule is represented by Thevenin equivalents derived by submodule dynamic phasors. The arm of the MMC is represented by Norton equivalents to guarantee the efficiency, considering both normal and dc-blocking conditions. The effectiveness of the proposed model in terms of accuracy and efficiency is validated by simulating an MMC-based HVdc transmission.

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46

Yin, Tianxiang, Lei Lin, Xiaojie Shi, and Kaiyuan Jing. "A Si/SiC Hybrid Full-bridge Submodule for Modular Multilevel Converter with Its Control Scheme." IEEE Journal of Emerging and Selected Topics in Power Electronics, 2022, 1. http://dx.doi.org/10.1109/jestpe.2022.3208602.

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Shen, Zhuoxuan, and Venkata Dinavahi. "Real-Time MPSoC-Based Electrothermal Transient Simulation of Fault Tolerant MMC Topology." February 1, 2019. https://doi.org/10.5281/zenodo.7685895.

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Among different modular multilevel converter (MMC) submodule (SM) topologies, the clamp double submodule (CDSM) has the capability of dc fault current limiting and utilizes a relatively small number of switching devices. Since CDSM has a more complex circuit structure than half-bridge or full-bridge SM, it is a significant challenge for the real-time electromagnetic transient (EMT) simulation for a multiterminal dc (MTDC) system containing CDSM MMC.This paper proposes the device-level electrothermal model of CDSM for real-time EMT simulation, which can accurately present the power losses, the junction temperatures, and the switching transient waveforms of individual switches consuming more computation resources. The individual insulated-gate bipolar transistors of the CDSM MMC during fault clearance transient are evaluated from both electromagnetic and thermal perspectives, which interact with each other dynamically. To ensure the real-time performance of the proposed model, the equivalent circuit model is combined with the device-level model. The system-level and device-level waveforms during normal operation and dc fault transient for a three-terminal dc system are both presented and compared with PSCAD/EMTDC and SaberRD. The simulation system was implemented on the Xilinx Zynq UltraScale+ ZCU102 multiprocessor system-on-chip (MPSoC) platform, and the results were captured by the oscilloscope in real-time.

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Magnanimo, Antonio, Markus Teschke, and Gerd Griepentrog. "Full-Bridge Submodule Development of an MMC-Like Topology for ASDEX Upgrade Toroidal Field Coils Power Supply." IEEE Transactions on Plasma Science, 2022, 1–7. http://dx.doi.org/10.1109/tps.2022.3179624.

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Ning, Guangfu, Yu Deng, Litao Du, et al. "Current‐Fed Single‐Stage Converter With MPPT and Auto‐Voltage‐Sharing Integrated for MVDC Grids." International Journal of Circuit Theory and Applications, February 23, 2025. https://doi.org/10.1002/cta.4471.

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ABSTRACTThis paper proposes a current‐fed single‐stage input‐parallel‐output‐series (IPOS) modular converter for a large‐scale photovoltaic (PV) generation connected to MVDC grids, which can realize maximum power point tracking and auto‐voltage‐sharing by only sampling the PV voltage and current. The submodule (SM) is integrated by an interleaved parallel boost unit and a full‐bridge LC series resonant unit. The simple pulse width modulation is adopted, while the drivers of different SMs are interleaved but with the same duty cycle set. Because the full‐bridge LC series resonant unit operates as a DC transformer (DCX) with zero‐current switching realized for all rectifier diodes, the voltage gain of SM is only related to the duty cycle of the interleaved parallel boost unit for the boost inductor current is continuous. Hence, without any SM output voltage nor input current sensors, the SMs can automatically share the output voltage by using the same duty cycle set for each SM. Moreover, the zero‐voltage‐switching can be realized for switches. A 1.5‐kW prototype with three SMs is built to verify the converter characteristics and control strategy.

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Xu, Chen, Jialu He, and Lei Lin. "Research on Capacitor-Switching Semi-Full-Bridge Submodule of Modular Multilevel Converter Using Si-IGBT and SiC-MOSFET." IEEE Journal of Emerging and Selected Topics in Power Electronics, 2020, 1. http://dx.doi.org/10.1109/jestpe.2020.3034451.

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Journal articles on the topic 'Full bridge submodule'

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