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A High-Gain Controllable Radiation Nulls SIGW Filtering Antenna With Improved Selectivity for 5G Millimeter-Wave Applications

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IEEE ANTENNAS AND WIRELESS PROPAGATION LETTERS 2024年第12期23卷 4328-4332页

作者： Wang, Lihui Wang, Wenjian Luo, Zhiyong Lin, Qiu-Hua Hou, Da Chen, Pengpeng Chen, Hao Sun Yat Sen Univ Sch Elect & Commun Engn Shenzhen 518107 Peoples R China Pengcheng Lab Shenzhen 518107 Peoples R China

In this letter, a substrate integrated gap waveguide (SIGW) filtering antenna with controllable radiation nulls, high-gain, and improved selectivity for millimeter-wave applications is proposed. A novel coupling feeding network (CFN) topology using multiple paths based on SIGW is presented to obtain a bandpass filtering response with a center frequency of 31 GHz, which is verified by an equivalent circuit model. The sideband rolloff characteristics of this antenna can be independently tuned by the SIGW and CFN to achieve radiation nulls. Furthermore, the selectivity and gain of the antenna are improved, benefiting from SIGW's frequency cutoff property and suppression of edge electric fields, respectively. The filtering antenna is fabricated, assembled, and measured. The measured results show a suppression level of 19.6 dB, a bandwidth of 14.2%(|S-11|< -10 dB), and a peak realized gain of 9.6 dBi.

关键词： Filtering Antennas Couplings Gain Cutoff frequency Antenna measurements Surface waves Controllable radiation nulls frequency cutoff high-gain improved selectivity millimeter-wave (MMW) filtering antenna substrate integrated gap waveguide (SIGW)

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Effect of austenitizing temperature on variant selection of martensite transformation in a 2 GPa grade steel

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JOURNAL OF MATERIALS RESEARCH AND technology-JMR&T 2024年 33卷 2794-2802页

作者： Zhao, Jun Hou, Zi-yong Wang, Bo Yang, He Wang, Ya-ru Chang, Zhi-yuan Zhang, Ling Wu, Gui-lin Huang, Xiao-xu State Key Lab Vanadium & Titanium Resource Compreh Panzhihua 617000 Sichuan Peoples R China Shanghai Univ Sch Mat Sci & Engn State Key Lab Adv Special Steel Shanghai Key Lab Adv Ferromet Shanghai 200444 Peoples R China Chongqing Univ Coll Mat Sci & Engn Int Joint Lab Light Alloys Minist Educ Chongqing 400044 Peoples R China Chongqing Univ State Key Lab Mech Transmiss Adv Equipment Chongqing 400044 Peoples R China Pangang Grp Co Ltd Inst Steel Technol Automobile & Household Applianc Panzhihua 617000 Sichuan Peoples R China Chongqing Univ Coll Mat Sci & Engn Electron Microscopy Ctr Chongqing 400044 Peoples R China

The correlation of prior austenite grain (PAG) size, mechanical properties, and the variant selection in martensite transformation of a 2 GPa grade automobile steel has been systematically investigated by using a combination of scaning electron microscopy (SEM), electron backscatter diffraction (EBSD), and uniaxial tesile tests. As the austenitizing temperature decreases from 970 degrees C to 870 degrees C, the as-quenched microstructure of the studied steel is fully lath martensite. Meanwhile, the average size of PAG is refined from 7.2 f 3.9 mu m to 2.1 f 1.2 mu m, and the volume fraction of high angle grain boundaries (HAGB) is increased from 59.8% to 72.3%, accompanied with an increased number fraction of grains belonging to closely spaced planes (CP) group. With the refinement of the PAGs, the martensitic variant selectivity becomes strong, and the Bain group variant selection discretely transites to the CP group, resulting in a dominate CP group. Consequently, a tensile strength of 2014 f 33 MPa, a tensile elongtation of 12.9 f 0.5% and a maximum strength x ductility production of 26.0 f 1.4 GPa & sdot;%, are obtained when the austenitization temperature is at 920 degrees C.

关键词： Microstructure Lath martensite Prior austenite grain size Mechanical properties Variant selection

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Comparative Study of Mechanically Modulated HIA with Magnetic Modulator Ring or Radial Movable Permanent Magnets

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JOURNAL OF ELECTRICAL engineering & technology 2025年第4期20卷 2377-2392页

作者： Liu, Long-jian Yu, Ke-xun Xie, Xian-fei Liu, Zhi-jian Kunming Univ Sci & Technol Fac Elect Power Engn Kunming 650500 Peoples R China Huazhong Univ Sci & Technol State Key Lab Adv Electromagnet Technol Wuhan 430074 Peoples R China

The homopolar inductor alternator (HIA) with magnetic modulator ring (MMR) has important applications in flywheel energy storage system, synchronous condenser, capacitor charge power supply (CCPS) and so on. But it has the disadvantage of high non-linearity of magnetic-flux regulation and the no-load iron core losses during idling conditions is not extremely low. In this paper, we propose using the HIA with radial movable permanent magnet (RMPM) to replace the HIA with MMR in the above application scenarios, and compared the HIA with MMR or RMPM in detail. The magnetic circuit model, the magnetic field and flux weakens ability, no-load iron core losses, flux regulation linearity, power density, the electromagnetic force and complexity and reliability of magnetic adjustment actuator (MAA) for HIA with MMR or RMPM are compared. The simulation results show that the HIA with RMPMs has much better magnetic field and flux weakens ability and flux regulation linearity, and also it has much lower no-load iron core loss under idle operating conditions. What's more, the electromagnetic force of MAA for HIA with RMPMs is much smaller than the HIA with MMR. But the MAA for HIA with RMPMs is more complex than that for the HIA with MMR, so its reliability is relatively lower. The power density of HIA with RMPMs is slightly smaller than the HIA with MMR. The difference of charge voltage between every pulse for CCPS based on HIA with RMPM is much less than that of the HIA with MMR. The research results in this paper are benefit for choosing between HIA with RMPM and HIA with MMR according to different performance requirement. The way of moving PM is also studied, and can guide the operation of HIA with RMPM.

关键词： Homopolar inductor alternator Radial movable permanent magnet Magnetic modulator ring

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Network algebraization and port relationship for power-electronic-dominated power systems

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IET RENEWABLE POWER GENERATION 2024年第S1期18卷 4519-4529页

作者： Ma, Rui Yang, Xiaowen Zhan, Meng Shandong Univ Sch Elect Engn Key Lab Power Syst Intelligent Dispatch & Control Minist Educ Jinan Peoples R China Huazhong Univ Sci & Technol Sch Elect & Elect Engn State Key Lab Adv Electromagnet Engn & Technol Wuhan 430074 Peoples R China

In the classical differential-algebraic equations (DAEs) framework for the traditional power system stability analysis, synchronous generators are depicted by differential equations and network by algebraic equations under the quasi-steady-state assumption. Differently, in the power-electronic-dominated power system (PEDPS), the dynamics of transmission lines of network for fully differential equations should be considered, due to the rapid response of converters' controls, for example, the alternating current controls. This poses a great challenge for the cognition, modeling, and analysis of the PEDPS. In this article, a nonlinear DAE model framework for the PEDPS is established with differential equations for the source nodes and algebraic equations for the dynamical electrical network, by generalizing the application scenarios of Kron reduction. The internal and terminal voltages of source nodes of converters are chosen as ports of nodes and network. Namely, the internal and terminal voltages of source nodes work as their output and input, respectively, whereas they work as the input and output of the algebraic network, respectively. The impact of dynamical network becomes clear, namely, it serves as a (linear) voltage divider and generates the terminal voltage based on the internal voltage of the sources simultaneously. By keeping only useful independent state variables, all differential equations for the transmission lines can be transferred to algebraic equations. With this simple model, the roles of both nodes and network become apparent, and it enhances the understanding of the PEDPS dynamics. On the other hand, broad simulations are conducted and compared to verify the proposed DAE framework for the PEDPS. As all independent variables have been kept in the model, it is found that they show the same computational accuracy, but better efficiency in computational time, compared to the electromagnetic-transient simulation results.

关键词： AC-DC power convertors differential algebraic equations differential equations integration power system dynamic stability renewable energy power conversion stability criteria voltage-source convertors

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Synchronization stability of power-grid-tied converters

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CHAOS 2023年第3期33卷 032102-032102页

作者： Ma, Rui Zhang, Yayao Yang, Ziqian Kurths, Juergen Zhan, Meng Lin, Congping Huazhong Univ Sci & Technol Sch Elect & Elect Engn State Key Lab Adv Electromagnet Engn & Technol Hubei Elect Power Secur & High Efficiency Key Lab Wuhan 430074 Peoples R China China Southern Power Grid Elect Power Res Inst SEP Guangzhou 510080 Peoples R China Potsdam Inst Climate Impact Res D-14473 Potsdam Germany Humboldt Univ Inst Phys D-12489 Berlin Germany Huazhong Univ Sci & Technol Sch Math & Stat Hubei Key Lab Engn Modeling & Sci Comp Wuhan 430074 Peoples R China Huazhong Univ Sci & Technol Ctr Math Sci Hubei Key Lab Engn Modeling & Sci Comp Wuhan 430074 Peoples R China

Synchronization stability is one of central problems in power systems, and it is becoming much more complicated with the high penetration of renewable energy and power electronics devices. In this paper, we review recent work by several nonlinear models for renewable-dominated power systems in terms of multiple timescales, in particular, grid-tied converters within the DC voltage timescale. For the simplest model, a second-order differential equations called the generalized swing equation by considering only the phase-locked loop (PLL) is obtained, which shows a similar form with the well-known swing equation for a synchronous generator in the traditional power systems. With more outer controllers included, fourth-order and fifth-order models can be obtained. The fourth-order model is called the extended generalized swing equation, exhibiting the combined function of grid synchronization and active power balance on the DC capacitor. In addition, a nonlinear model for a two coupled converter system is given. Based on these studies, we find that the PLL plays a key role in synchronization stability. In summary, the value of this paper is to clarify the key concept of the synchronization stability in renewable-dominated power systems based on different nonlinear models, which still lacks systematic studies and is controversial in the field of electrical power engineering. Meanwhile, it clearly uncovers that the synchronization stability of converters has its root in the phase synchronization concept in nonlinear sciences.

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Research on the electromagnetic Interference of Scanning Magnet Magnetic Field to Cable in Proton Therapy 4

Research on the Electromagnetic Interference of Scanning Mag...

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4th IEEE China International Youth Conference on Electrical engineering, CIYCEE 2023

作者： Shen, Xinyi Tan, Ping Wang, Xinze Lin, Yinjie Chen, Songbin Xiong, Haimin Qian, Zhihong Huazhong University of Science and Technology State Key Laboratory of Advanced Electromagnetic Technology School of Electrical and Electronic Engineering Wuhan430074 China

ISBN: (纸本)9798350305562

Proton therapy is a new method to treat tumors. The main method of proton therapy is the pencil beam scanning (PBS), whose core component is the scanning magnets. The beam is deflected under the magnetic field of the scanning magnets. Various cables are arranged near the scanning magnets. The excitation current and magnetic field of the scanning magnets will cause electromagnetic interference to the surrounding cables. To reduce electromagnetic interference, the shielding structure is designed. In this paper, the type of cables near the scanning magnets is analyzed first. Then, using Computer Simulation technology (CST) CABLE STUDIO, the magnet magnetic field is modeled, the influence of the magnetic fields on the strong electrical cables, weak electrical cables and multi-channel signal cables are simulated. This paper further analyzes the influence factors of the shielding frame such as the layer thickness, the size and the shielding material on shielding effect. It is concluded that the shielding effect of coaxial cable is better than that of single cable. The larger the thickness of the shielding frame, the smaller the size, the larger the conductivity and relative permeability of the shielding material, the better the shielding effect. © 2023 IEEE.

关键词： Signal interference

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Performance Enhancing Control of Frequency for Future Power Systems With Strong Uncertainties

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IEEE TRANSACTIONS ON INDUSTRIAL INFORMATICS 2024年第10期20卷 12439-12449页

作者： Shangguan, Xing-Chen Wei, Chen-Guang Zhang, Chuan-Ke He, Yong Jiang, Lin China Univ Geosci Sch Automat Wuhan 430074 Peoples R China Hubei Key Lab Adv Control & Intelligent Automat Co Wuhan 430074 Peoples R China Minist Educ Engn Res Ctr Intelligent Technol Geoexplorat Wuhan 430074 Peoples R China Univ Liverpool Dept Elect Engn & Elect Liverpool L69 3GJ England

The future power systems with renewable energy sources (RESs) and electric vehicles (EVs) are usually subject to strong uncertainties in system parameters, communication network, and disturbances, which may severely degrade the frequency control performance. This article proposes a performance enhancing load frequency control (LFC) scheme for future power systems with strong uncertainties based on the Kalman-filter (KF) control compensation method. First, the LFC of a multiarea interconnected power system (MAIPS) with RESs and EVs is conceptualized as a linear stochastic and discrete model. Then, KF is introduced to evaluate the unmeasurable states of the LFC, so as to design an additional KF-based state feedback control law. The KF-based control loop serves as compensation for the original controller of the LFC system. Next, an optimal compensation control gain of the KF-based control loop is derived based on a differential optimal calculation method to enhance the control performance of the LFC of MAIPS under strong uncertainties. Finally, simulation results are conducted on a typical three-area LFC systems that integrate RESs and EVs, which demonstrate that the proposed control strategy can provide better control performance and robustness than the original LFC strategy when the systems are subject to strong uncertainties.

关键词： Uncertainty Frequency control Stochastic processes Power system stability Measurement uncertainty Load modeling Generators Future power systems Kalman filter (KF) load frequency control (LFC) strong uncertainties

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A discrete-time looped functional approach and its application to discrete-time systems with cyclically varying delays

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SCIENCE CHINA-INFORMATION SCIENCES 2025年第8期68卷 1-15页

作者： Chen, Wen-Hu Zhang, Chuan-Ke Wang, Chen-Rui Xie, Ke-You He, Yong Zeng, Hong-Bing China Univ Geosci Sch Automat Wuhan 430074 Peoples R China Hubei Key Lab Adv Control & Intelligent Automat Co Wuhan 430074 Peoples R China Engn Res Ctr Intelligent Technol Geoexplorat Wuhan 430074 Peoples R China Hunan Univ Technol Sch Elect & Informat Engn Zhuzhou 412007 Peoples R China

This paper investigates the stability analysis problem of discrete-time systems with cyclically varying delays. Unlike previous studies, the delay investigated in this paper cyclically alternates between increasing and decreasing changes within its upper and lower bounds. First, to reasonably describe the cyclic variation characteristics of the delay, a discrete-time looped functional (DTLF) approach and a refined allowable delay set (ADS) are proposed. Then, based on the constructed DTLF with delay-product terms and using matrix-separation-based inequality to estimate its forward difference, delay-variation-interval-dependent stability conditions considering two different ADSs are derived. Finally, the effectiveness and superiority of the obtained conditions are demonstrated through two numerical examples.

关键词： cyclically varying delay discrete-time systems discrete-time looped functional allowable delay sets stability analysis

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Self-Trigger Solid-state Quasi-Square Wave Marx Generator Based on Cascode Structure

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IEEE TRANSACTIONS ON PLASMA SCIENCE 2025年

作者： Ren, Lvheng Yu, Liang Ma, Jiuxin Wang, Shixin Wang, Sicong Yao, Chenguo Dong, Shoulong Chongqing Univ State Key Lab Power Transmiss Equipment Technol Chongqing 400044 Peoples R China

With the increasingly extensive applications of all solid-state Marx generators in the defense and industrial fields, the development of traditional Marx topology faces many key issues, such as drive isolation, compact design, and slow discharge falling edge over high resistance. Hence, a novel compact quasi-square wave pulse generator is proposed. In Marx modules, by employing the cascode push-pull structure of the N-channel power MOSFETs and the P-channel power MOSFETs, the circuit can obtain tail-cut capability with single drive control. By means of interstages resistor-capacitor coupling, the tail-cut switch can be triggered on as designed to improve the output falling edge. The characteristic parameters of the eight-stage experimental prototype are as follows: an output voltage amplitude of 3.8 kV with both rising time and falling time shorter than 100 ns and a pulsewidth of 300-600 ns.

关键词： Switches Logic gates Capacitors MOSFET Discharges (electric) Generators Couplings Gate drivers Switching circuits Topology Nanosecond pulse generator self-trigger solid-state Marx circuits tail-cut switch

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Design and implementation of shear-horizontal mode surface acoustic wave formaldehyde gas sensor

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SURFACES AND INTERFACES 2024年 52卷

作者： Xu, Zhangliang Luo, Yang Fu, Hao Yuan, Rui Wei, Song China West Normal Univ Sch Elect Informat Engn Nanchong 637009 Sichuan Peoples R China Guilin Univ Elect Technol Sch Mech & Elect Engn Guilin 541000 Peoples R China

Surface acoustic wave (SAW) sensors have garnered significant attention due to high performance in gas detection. Love wave as the special mode of SAW has greater attractiveness for molecules detection in gas or liquid. To investigate the detection performance of Love wave SAW (Love-SAW) devices towards toxic gases, the influence of interdigitated electrodes on the propagating performance of Rayleigh and shear horizontal (SH) waves along ST-X and ST-90 degrees X quartz substrates was analyzed by finite element method (FEM). The effect of the guiding layer based on different substrates of SAW devices has been discussed by changing the thickness of the zinc oxide (ZnO) layer. The results indicate that the SH wave excited on ST-90 degrees X quartz substrate couples into the Love wave mode through the ZnO guiding layer, and Rayleigh waves in ST-X quartz do not exhibit mode coupling. The Love-SAW sensor covering the ZnO guiding layer (0.5 mu m) has shown high mass sensitivity. The vibration distribution of SH wave excited by different thicknesses of electrodes is different, indicating that the mass-loading is one of the reasons for the transformation of SH wave into Love wave. Furthermore, the 50 ppm, 95 ppm and 110 formaldehyde-load leads the short-circuit resonance frequency of the polyetherimide (PEI) covered Love-SAW devices to drop by 100.1 kHz, 200.2 kHz and 300.3 kHz, respectively. The maximum detection sensitivity reached about 2.73 kHz/ppm. This work can provide valuable insights for designing and investigating the SAW formaldehyde gas sensors.

关键词： Surface acoustic wave Guiding layer Shear-horizontal Formaldehyde gas sensing Sensitivity

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