Article
Engineering, Electrical & Electronic
Yangbin Zeng, Jialin Zheng, Zhengming Zhao, Weicheng Liu, Zuoxing Wang, Hong Li
Summary: This letter proposes an event-synchronous time-asynchronous (ESTA) method for CHIL simulations of modular multilevel converters (MMCs). The proposed method addresses the issue of extensive power circuit simulation calculations and reduces the calculation points of the simulator by employing data interaction events and state/switching events. The proposed ESTA method allows for accurate CHIL simulations even with significant computational tasks and offers a promising avenue for simulating large-scale MMCs in the CHIL simulation system.
IEEE TRANSACTIONS ON POWER ELECTRONICS
(2023)
Article
Energy & Fuels
Harith R. Wickramasinghe, Pingyang Sun, Georgios Konstantinou
Summary: This study demonstrates the interoperability of an emerging alternate arm converter (AAC) with the state-of-the-art modular multilevel converter (MMC) in high-voltage direct current (HVDC) systems based on a hybrid VSC-HVDC system. Through detailed analysis of an 800 MVA hybrid voltage source converter (VSC)-HVDC system, the study showcases the interoperability performance of the AAC under different operating scenarios and verifies its associated control functions.
Article
Automation & Control Systems
Binbin Li, Zigao Xu, Shengbo Wang, Linjie Han, Dianguo Xu
Summary: The article discusses the use of PHIL simulation in studying and verifying complex electric systems, with a focus on the damping impedance interface algorithm to ensure stability and low-frequency accuracy.
IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS
(2021)
Article
Engineering, Electrical & Electronic
Haozhe Jin, Wu Chen, Yeyuan Xie, Liangcai Shu, Yutao Xu
Summary: This article proposes an optimized asymmetric trapezoidal wave (ATW) modulation scheme for a modular multilevel resonant dc/dc converter (MMRDC) to reduce current stress over wide load and voltage ranges. The optimized operating point of MMRDC is derived based on the soft switching characteristic and reactive current analysis, considering low current stress and zero voltage switching constraint. The experimental results on a 4 kW MMRDC prototype verify the correctness and effectiveness of the analysis and the optimized ATW modulation scheme.
IEEE TRANSACTIONS ON POWER ELECTRONICS
(2023)
Article
Engineering, Electrical & Electronic
Nibedita Parida, Anandarup Das
Summary: This article presents an isolated dc-dc modular multilevel converter topology designed to extract power from the HVdc link, featuring two stages of power conversion and a high-voltage transformation ratio. Operating at medium-frequency ac reduces the size of the transformer and passive elements, while implementing a sinusoidal level-shifted pulsewidth modulation technique ensures voltage close to a sine wave.
IEEE TRANSACTIONS ON POWER ELECTRONICS
(2021)
Article
Engineering, Electrical & Electronic
Mustafa Kaya, Alessandro Costabeber, Alan Watson, Francesco Tardelli, Jon Clare
Summary: This article introduces a push-pull series connected (PPSC) ac-dc converter for high-voltage direct current applications. The proposed topology requires fewer submodules compared to a standard modular multilevel converter (MMC) for the same dc voltage. Each converter phase unit is connected via a center-tapped single-phase transformer, providing galvanic isolation. The required arm inductance can be merged into the transformer leakage inductance. The design, operation, and comparison with MMC are discussed in detail.
IEEE TRANSACTIONS ON POWER ELECTRONICS
(2022)
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
Energy & Fuels
Qing Chen, Rui Xie, Hao Lu, Xiang Zheng, Lijun Hang, Chunxiang Fu, Zhen He, Yuanbin He, Pingliang Zeng, Jian Qiu
Summary: Energy crisis and climate changes have posed great challenges to traditional power generation and transmission. The power transmission system of VSC-HVDC is gaining increasing attention due to its separate control of reactive and active power and low harmonic content, along with the advantages of modular multilevel converters (MMC). This paper proposes an improved method to suppress circulating current in MMC and presents simulation and experimental results to demonstrate its effectiveness.
Article
Engineering, Electrical & Electronic
Govind Avinash Reddy, Anshuman Shukla
Summary: In this article, a new enhanced modular multilevel converter (EMMC) is introduced, which addresses the drawbacks of the conventional modular multilevel converters (MMC). The EMMC, based on a new submodule (SM) structure, is fully modular and requires fewer switches and capacitors. It possesses the features of reduced energy-storage requirement and dc fault-tolerant capability.
IEEE TRANSACTIONS ON POWER ELECTRONICS
(2023)
Article
Automation & Control Systems
Saurav Dey, Tanmoy Bhattacharya
Summary: A modular multilevel dc-dc converter philosophy is proposed in this article to exchange power between HVdc links of different voltage levels. The converter operates symmetrically in four quadrants, unaffected by voltage polarity, allowing power flow direction/magnitude to remain constant even with reversal of power flow in the HVdc link. The working principle is analytically explained and validated through simulation and experimental results.
IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS
(2021)
Article
Automation & Control Systems
Tianxiang Yin, Lei Lin, Chen Xu, Donghai Zhu, Kaiyuan Jing
Summary: This article proposes a hybrid modular multilevel converter (MMC) topology based on SiC mosfet and Si IGBT. By improving the modulation scheme and introducing a specialized voltage balancing scheme, the performance of the system is enhanced. Simulation and experimental results demonstrate the feasibility of the hybrid MMC and its superiority in terms of cost, loss, and feasibility compared to others.
IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS
(2022)
Article
Automation & Control Systems
Levi M. Bieber, Joel A. Pfannschmidt, Liwei Wang, Juri Jatskevich, Wei Li
Summary: This article presents a hybrid five-level converter (H5LC) with cascaded full-bridge submodules (FBSMs) for high voltage direct current (HVdc) transmission. It introduces a voltage injection scheme and a bypass branch to reduce losses and enable fault blocking in the H5LC. The article also demonstrates the control capabilities and fault resilience of the H5LC through simulation studies and a lab-scale hardware implementation.
IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS
(2023)
Article
Engineering, Electrical & Electronic
Wei Luo, Yifan Ma, Changbao Zheng
Summary: An improved balancing method based on a novel selection algorithm for MMCs is proposed in this paper to address the problems of large calculation burden and high switching frequency in the traditional capacitor voltage balancing method. This method can avoid sorting operation of the arm SM voltages in each control cycle, greatly improving sorting efficiency while maintaining control precision of the capacitor voltages.
JOURNAL OF POWER ELECTRONICS
(2021)
Article
Engineering, Electrical & Electronic
Xiangyang Xia, Lei Xu, Xinxin Zhao, Xiaoyong Zeng, Jing Zhang, Yedan He, Haigan Yi
Summary: A novel model predictive control (MPC) has been designed for MMC-HVDC applications, optimizing the switching states of the MMC units, achieving voltage balance of the capacitor, and adjusting DC bus power distribution to avoid internal energy imbalance in the MMC. Simulation and experimental results have verified the effectiveness of the proposed control strategy.
JOURNAL OF POWER ELECTRONICS
(2021)
Article
Engineering, Electrical & Electronic
Futian Qin, Feng Gao, Yi Tang, Tao Xu, Jinyu Wang, Decun Niu
Summary: This article introduces a new nine-arm modular multilevel converter with improved hybrid submodules for middle arms, which can reduce the dc-side voltage, eliminate the dc offset in common mode voltages, and provides a control method for middle arm current. The feasibility and performance characteristics of the proposed 9A-MMC were verified through simulation and experimental results.
IEEE TRANSACTIONS ON POWER ELECTRONICS
(2021)
Article
Engineering, Electrical & Electronic
Irfan Sami, Syed Sabir Hussain Bukhari, Nasim Ullah, Jong-Suk Ro
Summary: This paper presents a new control scheme for encoder-less operation of multiphase induction motor speed control. Simulation experiments are conducted to compare the performance of different controllers, and the results show that FOTSMC has advantages in performance and SMC and FOTSMC are more robust compared to the traditional PI controller.
JOURNAL OF ELECTRICAL ENGINEERING & TECHNOLOGY
(2023)
Article
Computer Science, Information Systems
Zohaib Asghar, Kamran Hafeez, Dilshad Sabir, Bilal Ijaz, Syed Sabir Hussain Bukhari, Jong-Suk Ro
Summary: This paper considers diesel generators sets (DGs), battery storage systems (BSS) and Photovoltaic system (PV) in a centralized Energy Management System (EMS) to minimize grid power injection. Machine learning (ML) techniques are used to predict performance of regression models like ANN, WNN, LR, LR-I, LR-S, RF-T, RC-T, and GPR. Demand Side Management (DSM) techniques like peak shaving and valley filling are integrated with ML technique in a Hybrid energy source (HS) system. Results show effective reshaping of grid profile without load scheduling or disconnection, validated using Matlab simulation software.
Article
Engineering, Electrical & Electronic
Irfan Sami, Shafaat Ullah, Shafqat Ullah, Syed Sabir Hussain Bukhari, Naseer Ahmed, Muhammad Salman, Jong-Suk Ro
Summary: This paper proposes a novel super-twisting fractional-order sliding mode control (ST-FOSMC) for the outer loop speed control of the model predictive torque control (MPTC)-based induction motor drive system. It also presents a machine learning-based Gaussian Process Regression (GPR) framework for speed estimation. The performance of the proposed control and estimation strategy is evaluated using various test cases in Matlab/Simulink environment, demonstrating its effectiveness and improved performance.
Article
Mathematics, Interdisciplinary Applications
Ghulam Farid, Wajida Akram, Ferdous M. O. Tawfiq, Jong-Suk Ro, Fairouz Tchier, Saira Zainab
Summary: This article investigates inequalities for certain types of strongly convex functions using q-h integrals, providing refinements of well-known results for (alpha, m)- and ((h) over bar -m)-convex and related functions. Inequalities for q-integrals can be derived by setting the parameter h to zero. Some particular cases are discussed after proving the main results.
FRACTAL AND FRACTIONAL
(2023)
Article
Mathematics, Interdisciplinary Applications
Timilehin Gideon Shaba, Serkan Araci, Jong-Suk Ro, Fairouz Tchier, Babatunde Olufemi Adebesin, Saira Zainab
Summary: This study introduces a new family of analytic functions using the q-derivative operator and the q-version of the hyperbolic tangent function, and finds certain inequalities and their corresponding extremal functions. The results are sharp and valid.
FRACTAL AND FRACTIONAL
(2023)
Article
Mathematics, Interdisciplinary Applications
Nazar Khan, Kashif Khan, Ferdous M. Tawfiq, Jong-Suk Ro, Isra Al-shbeil
Summary: In this paper, the concept of quantum calculus is used to define a q-analogous of a fractional differential operator and explore its applications. New subclasses of uniformly q-starlike and q-convex functions are defined using this operator in association with a new generalized conic domain, Lambda(beta,q,gamma). The paper presents novel lemmas and investigates important features of these function classes, including inclusion relations, coefficient bounds, Fekete-Szego problem, and subordination results. The findings also lead to several known and new specific corollaries.
FRACTAL AND FRACTIONAL
(2023)
Article
Mathematics, Applied
Mohsan Raza, Mehak Tariq, Jong-Suk Ro, Fairouz Tchier, Sarfraz Nawaz Malik
Summary: The aim of this paper is to introduce a class of starlike functions related to Bernoulli's numbers of the second kind. We define phi(BS) ((zeta) over tilde) = ((zeta) over tilde /e((zeta) over tilde) -1)(2) = Sigma(infinity)(n=0) (zeta) over tilde B-n(n)2 /n! , where the coefficients of B-n(2) are Bernoulli numbers of the second kind. We then introduce a subclass of starlike functions F such that (zeta) over tildeF'((zeta) over tilde)/F((zeta) over tilde) (SIC) phi(BS) ((zeta) over tilde). We explore coefficient bounds, radii problems, structural formulas, inclusion relations, and sharp Hankel determinant problems of this class.
Article
Mathematics, Applied
Muhammad Ghafar Khan, Bilal Khan, Ferdous M. O. Tawfiq, Jong-Suk Ro
Summary: In this paper, we investigate coefficient functionals related to tangent functions and evaluate sharp coefficient bounds, sharp Fekete-Szego functionals, and sharp Zalcman functionals for this class of functions. We also provide majorization results for some non-vanishing holomorphic functions that are related to various domains in the open unit disk.
Article
Mathematics, Applied
Ghulam Farid, Hafsa Tariq, Ferdous M. O. Tawfiq, Jong-Suk Ro, Saira Zainab
Summary: This article aims to derive inequalities involving the unified Mittag-Leffler function, providing bounds for integral operators in generalized convexity. These findings extend and refine many existing inequalities. By assigning values to monotone functions, classical convexity results can be reproduced. Various Hadamard-type inequalities for classes related to convex functions are identified in remarks and some are also presented in the last section.
Article
Mathematics, Applied
Shahid Khan, Jong-Suk Ro, Fairouz Tchier, Nazar Khan
Summary: This work focuses on the application of geometric function theory, a branch of complex analysis, to the study of fuzzy sets. A novel operator La,?m:An & RARR;An is developed in the open unit disc & UDelta; using the Noor integral operator and the generalized Salagean differential operator. The fuzzy differential subordination for La,?m is developed, and a particular class of fuzzy analytic functions in & UDelta; is defined. Several new results relevant to this class are discovered through the concept of fuzzy differential subordination. Fundamental theorems, corollaries, and practical examples are presented.
Article
Computer Science, Information Systems
Sheikh Yasir Hammad, Junaid Ikram, Rabiah Badar, Syed Sabir Hussain Bukhari, Laiq Khan, Jong-Suk Ro
Summary: In this paper, a self-excited topology using third harmonic field excitation is proposed for brushless operation of the Wound Rotor Vernier Machine (WRVM). The proposed topology consists of two windings housed inside the stator periphery connected in series with a three-phase diode rectifier. When current is supplied by the inverter, a 4-pole and 12-pole Magneto Motive Force (MMF) is developed in the machine air gap. The third harmonic field induces a harmonic current in the rotor winding, which is rectified to excite the rotor field winding and achieve brushless operation.
Article
Mathematics, Interdisciplinary Applications
Amanullah, Muhammad Yousaf, Salman Zeb, Mohammad Akram, Sardar Muhammad Hussain, Jong-Suk Ro
Summary: This paper investigates the use of the Hermite wavelet method (HWM) for solving 12th and 13th order boundary value problems (BVPs) of ordinary differential equations (ODEs). The proposed algorithm converts the ODEs into a system of algebraic equations, which are then solved to obtain the approximate solution. Test problems were considered and compared with exact solutions and other numerical methods in the literature, showing the HWM-based algorithm to be more accurate than the homotopy perturbation method (HPM) and the differential transform method (DTM).
FRACTALS-COMPLEX GEOMETRY PATTERNS AND SCALING IN NATURE AND SOCIETY
(2023)
Article
Mathematics, Interdisciplinary Applications
Ali Turab, Wutiphol Sintunavarat, Jong-Suk Ro
Summary: Chemical graph theory is a mathematical science that applies graph theory to chemical structures and processes. Chemical graphs are widely used in cheminformatics to represent chemical interactions. In this paper, the authors investigate the existence of solutions to fractional boundary value problems on an isobutane graph, which has the chemical formula C4H10. The results are supported by fixed point theory and demonstrated with examples.
FRACTAL AND FRACTIONAL
(2023)
Article
Computer Science, Information Systems
Soheil Yousefnejad, Ebrahim Amiri, Mohsen Sarparast, Jong-Suk Ro
Summary: This paper investigates the impact of a defective solenoid on the performance of a DC series motor starter. It describes the effects of the starting system on the solenoid parts and establishes a circuit model to obtain the motor performance. Experimental measurements and theoretical discussion support the simulation results.
Article
Mathematics, Applied
Muhammmad Ghaffar Khan, Wali Khan Mashwani, Jong-Suk Ro, Bakhtiar Ahmad
Summary: The work presented in this article aims to establish a new subfamily of holomorphic functions and investigate the estimate problems of their Hankel determinants and logarithmic coefficients.