Article
Engineering, Electrical & Electronic
Shaoze Zhou, Binbin Li, Jingkun Wang, Dianguo Xu
Summary: Modular multilevel converter (MMC) is considered an emerging topology in medium-voltage variable-speed motor drive applications, especially for driving fan-/pump-like loads. A simple and cost-effective modified MMC topology is introduced in this brief, which provides high torque to motor during zero/low frequency and is particularly suitable for fan-/pump-like loads. The validity and effectiveness of this topology are verified through experimental results.
IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS II-EXPRESS BRIEFS
(2021)
Article
Energy & Fuels
Shaoze Zhou, Binbin Li, Dianguo Xu, Gen Li
Summary: The modular multilevel converter (MMC) is a promising topology for medium-voltage drive applications. A hybrid MMC (HMMC) with a thyristor instead of IGBT as the DC-link switch is proposed to address the challenge of large cell capacitor voltage ripple. A new control scheme is proposed to ensure the safe operation of the thyristor and improve the reliability of HMMC. Experimental results validate the effectiveness of the proposed scheme for starting up a motor from standby mode to rated speed with full torque.
CSEE JOURNAL OF POWER AND ENERGY SYSTEMS
(2023)
Article
Engineering, Multidisciplinary
Tarek Younis, Paolo Mattavelli, Igino Toigo, Michele Corradin
Summary: This paper proposes a capacitor voltage control scheme for a three-phase modular multilevel converter (MMC) with optimized capacitor sizing. Unlike the existing circulating current control, the proposed controller uses the middle capacitor voltage to control the second-order harmonic component of the circulating current. The proposed controller can effectively control the circulating current to be constant or inject second-order harmonics to reduce the capacitor sizing. Detailed analysis, controller design, and performance of the proposed scheme are presented in this paper. The effectiveness of this study is confirmed by simulation and experimental results.
IEEE TRANSACTIONS ON INDUSTRY APPLICATIONS
(2023)
Article
Automation & Control Systems
Jinyu Wang, Yi Tang, Yang Qi, Pengfeng Lin, Zhenbin Zhang
Summary: This article introduces a simple and effective startup strategy for MMCs based on deadbeat predictive current control, which achieves fast and safe startup without the need for traditional controller design and parameter tuning, reducing design burdens and structural complexities. Experimental results verify the effectiveness and performance of the developed strategy.
IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS
(2021)
Article
Engineering, Electrical & Electronic
Tarek Younis, Paolo Mattavelli, Igino Toigo, Michele Corradin
Summary: This article discusses a modified MMC topology designed for low-voltage systems to reduce the high capacitance requirement. The design and optimization process of this structure, along with the investigation of various parameters and a control scheme for voltage and current regulation, are presented in this study. The outcomes are verified through simulation and experiments.
IEEE TRANSACTIONS ON POWER ELECTRONICS
(2021)
Article
Energy & Fuels
Guanlong Jia, Mingshuo Li, Binhao Shi, Xinchao Yu, Xiaoming Liu
Summary: This paper proposes an innovative high-frequency voltage injection method to reduce the voltage fluctuation in capacitor in variable speed drives and improve the performance of motors at low frequency. The feasibility and effectiveness of the proposed method are verified through simulation and experiment.
Article
Automation & Control Systems
Duc Dung Le, Dong-Choon Lee
Summary: This article proposes a method to determine the average submodule capacitor voltage in a flying-capacitor modular multilevel converter (FC-MMC) in order to reduce current stresses and improve total harmonic distortion (THD) of the phase voltages. The method introduces higher ripple in the low-frequency voltage by partially alleviating the low-frequency power fluctuation, and determines the average SM capacitor voltage based on this ripple value. This allows for a decrease in the ac-circulating current amplitude and a reduction in current stresses in switching devices, inductors, and flying capacitors. Additionally, it improves the THD of the phase voltage in low-speed operation.
IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS
(2022)
Article
Engineering, Electrical & Electronic
Mohamed Atef Tawfik, Mohammad Sameer Irfan, Chungu Lee, Ashraf Ahmed, Joung-Hu Park
Summary: This paper presents a power decoupling scheme for medium-voltage motor drives based on flux cancelation method and sliding mode controller. The scheme eliminates the adverse effects of sub-module capacitor voltage ripple on system performance and lifetime by utilizing a three-winding high-frequency transformer to couple and cancel the ripple power.
JOURNAL OF POWER ELECTRONICS
(2022)
Article
Engineering, Electrical & Electronic
Lingbo Zhou, Canfeng Chen, Jian Xiong, Kai Zhang
Summary: This article proposes a modified individual capacitor voltage balancing method for MMCs with phase-shifted carrier pulsewidth modulation (CPS-PWM) to solve the problem of poor dynamic performance at low output power. The proposed method incorporates the information of arm current into the balancing algorithm to cancel out the coupling effect of output power on balancing control, showing better robustness and dynamic performance.
IEEE TRANSACTIONS ON POWER ELECTRONICS
(2022)
Article
Engineering, Electrical & Electronic
Tarek Younis, Paolo Mattavelli, Paolo Magnone, Igino Toigo, Michele Corradin
Summary: The rapid growth of renewable energy sources in low-voltage networks has led to increased interest in efficient and compact energy conversion systems. This article proposes an improved modulation technique to reduce capacitor requirements in existing converters. By combining two solutions, the total capacitor demand can be significantly reduced across the entire modulation range.
IEEE JOURNAL OF EMERGING AND SELECTED TOPICS IN POWER ELECTRONICS
(2022)
Article
Engineering, Electrical & Electronic
Debdeep Samajdar, Tanmoy Bhattacharya
Summary: This article presents a control framework based on a generalized decoupled double synchronous reference frame control for optimizing (minimizing) the arm energy deviations using only instantaneous values of currents and voltages, as well as simple integral or proportional control. Extensive analysis is conducted to find a tradeoff between energy deviation minimization and arm current rms, and the viability of the proposed capacitor voltage ripple optimization method is confirmed through simulation and experiment.
IEEE TRANSACTIONS ON POWER ELECTRONICS
(2022)
Article
Automation & Control Systems
Yue Zhang, Fujin Deng, Jiehua Hou, Pengyuan Jiang, Hanlu Zhang, Kangshun Zhu, Yihua Hu, Sergio Vazquez
Summary: This article proposes a cascaded MMC and CCV based drive system to overcome the challenge of large capacitor voltage fluctuation in low-speed drive. The MMC provides medium-frequency AC voltage to the CCV, which converts it into low-frequency AC output required by the machine. Detailed analysis of MMC's operation frequency, device current stress, and SM capacitance are presented. The proposed drive system can operate at zero/low frequency under rated load torque, with smaller SM capacitance compared to existing methods. Simulation and experimental studies confirm the effectiveness of the proposed system.
IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS
(2023)
Article
Energy & Fuels
Mohamed Atef Tawfik, Mohammad Sameer Irfan, Ashraf Ahmed, Joung-Hu Park
Summary: In this paper, a modular multilevel converter (MMC) with a wireless magnetic power decoupling approach suitable for medium-voltage high-power variable-speed machine drives is proposed. The power decoupling approach is independent of the operating frequency, solving the issue of wide fluctuations of low-frequency voltage ripple components in submodule (SM) capacitors. The use of wireless magnetic elements reduces the high-voltage insulation between the transformer windings, resulting in a significant reduction in system size.
CSEE JOURNAL OF POWER AND ENERGY SYSTEMS
(2022)
Article
Energy & Fuels
Kailun Wang, Qiang Song, Shukai Xu
Summary: Increasing modulation index by utilizing negative voltage states can reduce capacitor usage of modular multilevel converters. A numerical calculation method is proposed to accurately determine the minimum energy storage requirement, and it is applicable for various operating conditions and proportions of modules. Simulation results verify the feasibility and accuracy of the proposed method.
Article
Engineering, Electrical & Electronic
Jian Liu, Dong Dong
Summary: This article presents a modified MMC called HL-MMC, which integrates HV voltage source converters (VSCs) to replace a portion of MMC submodules (SMs), resulting in reduced cost and conduction losses. The HL-MMC also reduces the energy storage requirement and provides a dc-fault tolerant capability through the combination of HV VSCs and a dc hybrid circuit breaker. Experimental validation and simulation models are provided to illustrate the effectiveness of the proposed topology.
IEEE TRANSACTIONS ON POWER ELECTRONICS
(2022)
Article
Automation & Control Systems
Shuxin Zhang, Binbin Li, Wei Wang, Yujie Zhang, Dianguo Xu, Gen Li, Jun Liang
Summary: This article discusses a novel hybrid modular interline current flow controller based on H-bridge submodules and thyristor valves, suitable for applications requiring high voltage and large power capacity. In addition to presenting its circuit structure and operation principle, a control strategy is proposed. The effectiveness of the controller is verified through simulations and building a downscaled prototype.
IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS
(2022)
Article
Engineering, Electrical & Electronic
Xiaodong Zhao, Binbin Li, Bingxu Zhang, Dianguo Xu
Summary: This paper proposes a high-power step-up dc/dc converter dedicated to dc offshore wind farms, which greatly reduces the number of devices, costs, losses, and energy storage requirements by using a combination of half-bridge submodules, thyristors, diodes, and transformers. The effectiveness and validity are confirmed by simulation and experimental results.
IEEE TRANSACTIONS ON POWER ELECTRONICS
(2022)
Article
Spectroscopy
Binbin Li, Changchun Hao, Hengyu Liu, Haiyan Yang, Kunfeng Zhong, Mingduo Zhang, Runguang Sun
Summary: The interaction between graphene oxide (GO) and lysozyme (Lyz) is influenced by temperature and pH, leading to significant changes in structure and secondary structure. Under acidic conditions, lysozyme is found to have a high density adsorbed on the GO surface, while increasing pH results in a progressive decrease in adsorbed Lyz density.
SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
(2022)
Article
Engineering, Electrical & Electronic
Binbin Li, Bingxu Zhang, Yujie Zhang, Lei Li, Dianguo Xu
Summary: This article presents a thyristor-submodule hybrid dc/dc converter (TSDC) that combines the advantages of low cost, low conduction loss, and high robustness of thyristors with the high controllability of cascaded half-bridge submodules. The TSDC offers efficient dc/dc conversion, reliable thyristor switching, wide voltage operation range, and the ability to block dc faults without the need for dc circuit breakers.
IEEE JOURNAL OF EMERGING AND SELECTED TOPICS IN POWER ELECTRONICS
(2022)
Article
Engineering, Electrical & Electronic
Zigao Xu, Binbin Li, Shengyuan Li, Xiongfei Wang, Dianguo Xu
Summary: This article develops the MMC signal-flow graph (SFG), providing an analytical transfer function to quantitatively estimate the attenuation degree of MMC harmonics, in order to guide the model truncation. Moreover, the SFG offers an intuitive understanding of the mathematical characteristics of MMC and helps to reduce modeling calculations. Additionally, the conversion formula of MMC multiple input multiple output and single input single output admittance is derived based on the truncated model, further simplifying the stability analysis.
IEEE TRANSACTIONS ON POWER ELECTRONICS
(2022)
Article
Engineering, Electrical & Electronic
Huijie Jiang, Fujin Deng, Zheng Wang, Zhixiang Zou, Binbin Li, Frede Blaabjerg
Summary: This article proposes a harmonic optimization strategy to improve the harmonic performance of modular multilevel converters under submodule capacitor voltage reduction control. By adjusting the phase-shift angle and capacitor voltage to their optimal values, the converter's harmonics can be improved.
IEEE TRANSACTIONS ON POWER ELECTRONICS
(2022)
Article
Engineering, Electrical & Electronic
Lei Li, Binbin Li, Zhiyuan Wang, Ming Yang, Dianguo Xu
Summary: This article proposes a monopolar symmetrical dc-dc converter, which achieves the goals of small installed capacity, low cost, low power loss, lightweight, and small footprint through partial-power processing and improved phase-shifted carrier pulsewidth modulation. The effectiveness of the proposed converter has been verified by simulation and experimental results.
IEEE TRANSACTIONS ON POWER ELECTRONICS
(2022)
Article
Engineering, Electrical & Electronic
Qiang Yu, Fujin Deng, Chengkai Liu, Zheng Wang, Binbin Li, Frede Blaabjerg
Summary: This article analyzes the high-frequency current ripple in the dc link of MMCs under 2N+1 SUPWM and proposes a control method to reduce the dc-link current ripple, which effectively improves the performance of the MMC.
IEEE TRANSACTIONS ON POWER ELECTRONICS
(2022)
Article
Urology & Nephrology
Jinqing Zhang, Binbin Li, Gang Li, Zengshi Yang, Ning Ye, Yihao Liu, Hongbing Zhuo, Jingfan Hong
Summary: This study assessed a novel ureteroscopic technique for treating upper urinary calculi in a lateral decubitus body position. The results showed that this technique is safe and effective, especially for upper ureteral calculi.
Article
Computer Science, Artificial Intelligence
Zhenyuan Zhang, Bin Li, Luning Liu
Summary: This paper investigates the impacts of AI-based conversational agents on firms' operational performance. Results show that the introduction of an AI-based conversational agent increases the average call length and has no significant influence on call numbers. There is also a heterogeneous effect among different time blocks. These findings have important implications for the operational management of call centers.
APPLIED ARTIFICIAL INTELLIGENCE
(2023)
Article
Engineering, Electrical & Electronic
Zigao Xu, Binbin Li, Xiongfei Wang, Frede Blaabjerg, Dianguo Xu
Summary: This article proposes a unified model to study the high-frequency resonance (HFR) in the modular multilevel converter (MMC). By changing the gain of the model, the high-frequency characteristics of the MMC under different control strategies can be reflected. The analysis based on this model reveals the worst cases of HFR risk and the limitation of low-pass filter (LPF) order on MMC high-frequency damping. A joint design method for LPF and passive damper is proposed to completely eliminate the HFR risk without sacrificing much dynamic performance of MMC. An alternative HFR suppression method based on delay time adjustment is also developed.
IEEE TRANSACTIONS ON POWER ELECTRONICS
(2022)
Article
Chemistry, Multidisciplinary
Zhixian Liao, Yingzong Jiao, Zhiwen Suo, Binbin Li, Xiaodong Zhao, Linjie Han, Dianguo Xu
Summary: This paper proposes a three-port power electronic transformer based on magnetic integration, which can directly obtain low-voltage DC output. It has the advantages of compact structure and reduced cost. Compared with existing transformers, it can save a large amount of magnetic volume and device cost. The feasibility of the transformer has been verified by simulation and experiments.
APPLIED SCIENCES-BASEL
(2022)
Article
Computer Science, Information Systems
Zhipeng Liao, Keqing Duan, Jinjun He, Zizhou Qiu, Binbin Li
Summary: This paper introduces an end-to-end robust adaptive beamforming (RBF) method using a two-stage convolutional neural network to address advancements in jamming technology. The first stage evaluates the covariance matrix precisely using finite snapshots, while the second stage maps the first stage's output to an adaptive weight vector. The two-stage structure enables the network to possess practical physical meaning, allowing for satisfying performance even with array gain/phase errors.
Article
Energy & Fuels
Shaoze Zhou, Binbin Li, Dianguo Xu, Gen Li
Summary: The modular multilevel converter (MMC) is a promising topology for medium-voltage drive applications. A hybrid MMC (HMMC) with a thyristor instead of IGBT as the DC-link switch is proposed to address the challenge of large cell capacitor voltage ripple. A new control scheme is proposed to ensure the safe operation of the thyristor and improve the reliability of HMMC. Experimental results validate the effectiveness of the proposed scheme for starting up a motor from standby mode to rated speed with full torque.
CSEE JOURNAL OF POWER AND ENERGY SYSTEMS
(2023)
Proceedings Paper
Computer Science, Artificial Intelligence
Long Qian, Zhigang Wang, Zhiqiang Zhou, Dong Li, Xinjie Peng, Binbin Li, Bin Jiao
Summary: This paper proposes a method to optimize the extreme learning machine using the sparrow search algorithm for the fault diagnosis of rolling bearings in motors. Experimental results show that this method can achieve faster classification and diagnosis of faults, demonstrating good time stability of the proposed model.
ADVANCED INTELLIGENT TECHNOLOGIES FOR INDUSTRY
(2022)
