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Optimization of Generator Based on Gaussian Process Regression Model with Conditional Likelihood Lower Bound Search

ces Transactions on Electrical Machines and Systems 2024年第1期8卷 32-42页

作者： Xiao Liu Pingting Lin Fan Bu Shaoling Zhuang Shoudao Huang ces&IEEE the College of Electrical and Information Engineering Hunan UniversityChangsha 410082China ces

The noise that comes from finite element simulation often causes the model to fall into the local optimal solution and over fitting during optimization of generator.Thus,this paper proposes a Gaussian Process Regression(GPR)model based on Conditional Likelihood Lower Bound Search(CLLBS)to optimize the design of the generator,which can filter the noise in the data and search for global optimization by combining the Conditional Likelihood Lower Bound Search method.Taking the efficiency optimization of 15 kW Permanent Magnet Synchronous Motor as an example.Firstly,this method uses the elementary effect analysis to choose the sensitive variables,combining the evolutionary algorithm to design the super Latin cube sampling plan;Then the generator-converter system is simulated by establishing a co-simulation platform to obtain data.A Gaussian process regression model combing the method of the conditional likelihood lower bound search is established,which combined the chi-square test to optimize the accuracy of the model globally.Secondly,after the model reaches the accuracy,the Pareto frontier is obtained through the NSGA-II algorithm by considering the maximum output torque as a constraint.Last,the constrained optimization is transformed into an unconstrained optimizing problem by introducing maximum constrained improvement expectation(CEI)optimization method based on the re-interpolation model,which cross-validated the optimization results of the Gaussian process regression model.The above method increase the efficiency of generator by 0.76%and 0.5%respectively;And this method can be used for rapid modeling and multi-objective optimization of generator systems.

关键词： Generator optimization Gaussian Process Regression(GPR) Conditional Likelihood Lower Bound Search(CLLBS) Constraint improvement expectation(CEI) Finite element calculation

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Vibration Suppression for Active Magnetic Bearings Using Adaptive Filter with Iterative Search Algorithm

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ces Transactions on Electrical Machines and Systems 2024年第1期8卷 61-71页

作者： Jin-Hui Ye Dan Shi Yue-Sheng Qi Jin-Hui Gao Jian-Xin Shen IEEE Department of Electrical Engineering Zhejiang UniversityHangzhou 310027China ces and IEEE

Active Magnetic Bearing(AMB) is a kind of electromagnetic support that makes the rotor movement frictionless and can suppress rotor vibration by controlling the magnetic force. The most common approach to restrain the rotor vibration in AMBs is to adopt a notch filter or adaptive filter in the AMB controller. However, these methods cannot obtain the precise amplitude and phase of the compensation current. Thus, they are not so effective in terms of suppressing the vibrations of the fundamental and other harmonic orders over the whole speed range. To improve the vibration suppression performance of AMBs,an adaptive filter based on Least Mean Square(LMS) is applied to extract the vibration signals from the rotor displacement signal. An Iterative Search Algorithm(ISA) is proposed in this paper to obtain the corresponding relationship between the compensation current and vibration signals. The ISA is responsible for searching the compensating amplitude and shifting phase online for the LMS filter, enabling the AMB controller to generate the corresponding compensation force for vibration suppression. The results of ISA are recorded to suppress vibration using the Look-Up Table(LUT) in variable speed range. Comprehensive simulations and experimental validations are carried out in fixed and variable speed range, and the results demonstrate that by employing the ISA, vibrations of the fundamental and other harmonic orders are suppressed effectively.

关键词： Active Magnetic Bearing(AMB) Adaptive filter Iterative search algorithm Least mean square(LMS) Vibration suppression

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Wireless Power Supply Based on MNG-MNZ Metamaterial for Cardiac Pacemakers

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ces Transactions on Electrical Machines and Systems 2024年第1期8卷 103-112页

作者： Weihua Chen Jingtao Jia Xiaoheng Yan Yuhang Song Jiayi Li Faculty of Electrical and Control Engineering Liaoning Technical UniversityNo.188Longwan South StreetXingchengHuludao 125105China ces

To solve the low power transfer efficiency and magnetic field leakage problems of cardiac pacemaker wireless powering, we proposed a wireless power supply system suitable for implanted cardiac pacemaker based on mu-negative(MNG) and mu-nearzero(MNZ) metamaterials. First, a hybrid metamaterial consisted of central MNG unit for magnetic field concentration and surrounding MNZ units for magnetic leakage shielding was established by theoretical calculation. Afterwards, the magnetic field distribution of wireless power supply system with MNG-MNZ metamaterial slab was acquired via finite element simulation and verified to be better than the distribution with conventional MNG slab deployed. Finally, an experimental platform of wireless power supply system was established with which power transfer experiment and system temperature rise experiment were conducted.Simulation and experimental results showed that the power transfer efficiency was improved from 44.44%,19.42%, 8.63% and 6.19% to 55.77%, 62.39%, 20.81%and 14.52% at 9.6 mm, 20 mm, 30 mm and 50 mm,respectively. The maximum SAR acquired by SAR simulation under human body environment was-7.14 dbm and maximum reduction of the magnetic field strength around the receiving coil was 2.82 A/m. The maximum temperature rise during 30min charging test was 3.85℃,and the safety requirements of human bodies were met.

关键词： Cardiac pacemaker MNG metamaterial MNZ metamaterial Wireless power supply system

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The Use of Smart Textiles in the Healthcare Space: Towards an Improvement of the User-Patient Experience

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Journal of Textile Science and Technology 2024年第2期10卷 41-50页

作者： Balkis Ellouze Marwa Damak Department of Design Higher Institute of Arts and Crafts of Sfax University of Sfax Sfax Tunisia ces Lab National Engineering School of Sfax Sfax Tunisia

This article explores the role of smart textiles in transforming healthcare environments into spaces that prioritize patient well-being. We will examine the advantages of smart textiles in healthcare settings, such as the real-time monitoring of vital signs through connected clothing. Additionally, we will introduce metadesign as a design approach that considers the interactions between users, healthcare environments, and technologies to create fulfilling experiences. By combining the advanced features of smart textiles with a patient-centered metadesign approach, it becomes possible to create care spaces that cater to patient needs. The objective of this article is to present the integration of metadesign in the design of smart textiles as a process aimed at enhancing the quality of the patient user experience. In this process, we will emphasize the collaborative approach and embrace technological innovation to harness the potential for ongoing improvement and provide users with high-quality experiences. Lastly, we will underscore the significance of adopting a multidimensional approach to evaluate the impact of smart textiles on the patient user experience.

关键词： Smart Textiles Healthcare Space User-Patient Experience Metadesign

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An Analytic Method of Segmented PWM Duty Cycle for Switched Reluctance Motor

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ces Transactions on Electrical Machines and Systems 2023年第2期7卷 163-170页

作者： Chaozhi Huang Yuliang Wu Hongwei Yuan Wensheng Cao Yongmin Geng ces the School of Electrical and Automation Jiangxi University of Science and TechnologyGanzhou341000China

In view of the large current peak and torque ripple in the actual current chopping control of switched reluctance motor,a segmented PWM duty cycle analysis method of switched reluctance motor based on current chopping control is proposed in this paper.The method realizes the control of the winding current by adjusting the average voltage of the two ends of the winding in one cycle through the PWM duty cycle.At the same time,according to the inductance linear model,the conduction phase is divided into a small inductance region and an inductance rising region,and the analytical formulas of PWM duty cycle in the two regions are deduced respectively.Finally,through matlab/simulink simulation and motor platform experiment,the current chopping control is compared with the segmented PWM duty cycle analysis method in this paper.Simulation and experimental results show that the segmented PWM duty cycle analysis method can effectively reduce the current peak and torque ripple,and has high practical application value.

关键词： Switched Reluctance Motor Current Chopping Control PWM Duty Cycle Current Peak Torque Ripple

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Research on the Voltage Supporting Capability of Multi-VSC-HVDC Subsystems Operation Strategy to Receiving-end LCC-HVDC Network in Weak AC Grid

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ces Transactions on Electrical Machines and Systems 2023年第1期7卷 11-20页

作者： Tao Li Yongli Li Yuchen Zhu IEEE the School of Electrical Automation and Information Engineering Tianjin UniversityTianjin300072China ces

For the hybrid multi-infeed HVDC system in which the receiving-end grid is a strong AC grid including LCC-HVDC subsystems and multiple VSC-HVDC subsystems,it has higher voltage support capability.However,for weak AC grid,the voltage support capability of the multi-VSC-HVDC subsystems to the LCC-HVDC subsystem(voltage support capability-mVSCs-LCC)can resist the risk of commutation failure.Based on this consideration,this paper proposes an evaluation index called Dynamic Voltage Support Strength Factor(DVSF)for the hybrid multi-infeed system,and uses this index to qualitatively judge the voltage support capability-mVSCs-LCC in weak AC grid.In addition,the proposed evaluation index can also indirectly judge the ability of the LCC-HVDC subsystem to suppress commutation failure.Firstly,the mathematical model of the power flow of the LCC and VSC networks in the steady-state is analyzed,and the concept of DVSF applied to hybrid multi-infeed system is proposed.Furthermore,the DVSF index is also used to qualitatively judge the voltage support capability-mVSCs-LCC.Secondly,the influence of multiple VSC-HVDC subsystems with different operation strategies on the DVSF is analyzed with reference to the concept of DVSF.Finally,the indicators proposed in this paper are compared with other evaluation indicators through MATLAB simulation software to verify its effectiveness.More importantly,the effects of multi-VSC-HVDC subsystems using different coordinated control strategies on the voltage support capability of the receiving-end LCC-HVDC subsystem are also verified.

关键词： Hybrid multi-infeed HVDC system Voltage support Multi-VSC-HVDC LCC-HVDC Commutation failure DVSF Control strategy

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An Improved DITC Control Method Based on Turn-on Angle Optimization

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ces Transactions on Electrical Machines and Systems 2023年第4期7卷 379-389页

作者： Chaozhi Huang Wensheng Cao Zhou Chen Yuliang Wu Yongmin Geng the School of Electrical and Automation Jiangxi University of Science and TechnologyGanzhou 341000China ces

Switched reluctance motor(SRM)usually adopts Direct Instantaneous Torque Control(DITC)to suppress torque ripple.However,due to the fixed turn-on angle and the control mode of the two-phase exchange region,the conventional DITC control method has low adaptability in different working conditions,which will lead to large torque ripple.For this problem,an improved DITC control method based on turn-on angle optimization is proposed in this paper.Firstly,the improved BP neural network is used to construct a nonlinear torque model,so that the torque can be accurately fed back in real time.Secondly,the turn-on angle optimization algorithm based on improved GRNN neural network is established,so that the turn-on angle can be adjusted adaptively online.Then,according to the magnitude of inductance change rate,the two-phase exchange region is divided into two regions,and the phase with larger inductance change rate and current is selected to provide torque in the sub-regions.Finally,taking a 3-phase 6/20 SRM as example,simulation and experimental verification are carried out to verify the effectiveness of this method.

关键词： Switched Reluctance Motor Turn-on Angle Optimization Neural Network Inductance Change Rate Torque Ripple

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Design and Analysis of Asymmetric Rotor Pole Type Bearingless Switched Reluctance Motor

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ces Transactions on Electrical Machines and Systems 2022年第1期6卷 3-10页

作者： Zhenyao Xu Qingguo Yu Fengge Zhang ces IEEE Shenyang University of Technology TechnologyShenyang110870China

Bearingless switched reluctance motor(BSRM) not only combines the merits of bearingless motor(BM) and switched reluctance motor(SRM), but also decreases the vibration and acoustic noise of SRM, so it could be a strong candidate for high-speed driving fields. Under the circumstances, a 12/14 BSRM with hybrid stator pole has been proposed due to its high output torque density and excellent decoupling characteristics between torque and suspension force. However, this motor has torque dead-zone, which leads to problems of self-start at some rotor positions and large torque ripple during normal operation. To solve the existing problems in the 12/14 type, an asymmetric rotor pole type BSRM is proposed. The structure and design process of the proposed motor is presented in detail. The characteristics of the proposed motor is analyzed and compared with that of the 12/14 type. Furthermore, prototype of the proposed structure is designed, manufactured and experimented. Finally, simulation and test results are illustrated and analyzed to prove the validity of the proposed structure.

关键词： Asymmetric rotor pole bearingless switched reluctance motor self-start torque ripple reduction

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Analysis of a Novel Mechanically Adjusted Variable Flux Permanent Magnet Homopolar Inductor Machine with Rotating Magnetic Poles for Flywheel Energy Storage System

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ces Transactions on Electrical Machines and Systems 2022年第3期6卷 315-323页

作者： Qing Li Mingcheng Lyu Jiangtao yang Shoudao Huang IEEE College of Electrical and Information Engineering Hunan UniversityChangsha410082China ces

Permanent magnet homopolar inductor machine(PMHIM) has attracted much attention in the field of flywheel energy storage system(FESS) due to its merits of simple structure,brushless excitation, and rotor flywheel integration. However, the air-gap flux generated by the PM cannot be adjusted, which would cause large electromagnetic losses in the standby operation state of FESS. To solve this problem, a novel mechanically adjusted variable flux permanent magnet homopolar inductor machine with rotating magnetic poles(RMP-PMHIM) is proposed in this paper. The permanent magnet poles are rotated by an auxiliary rotating device and the purpose of changing the air-gap flux is achieved. First, the structure and operation principle of the proposed RMP-PMHIM are explained. Second,the flux weakening principle of the RMP-PMHIM is analyzed and the equivalent magnetic circuit models under different flux weakening states are built. Third, the parameters of the PM and its fixed structure are optimized to obtain the good electromagnetic performance. Fourth, the electromagnetic performance, including the air-gap flux density, back-EMF, flux weakening ability, loss, etc. of the proposed RMP-PMHIM are investigated and compared. Compared with the non-rotating state of the PM of RPM-PMHIM, the air-gap flux density amplitude can be weakened by 99.95% when the PM rotation angle is 90 degrees, and the no-load core loss can be suppressed by 99.98%,which shows that the proposed RPM-PMHIM is a good candidate for the application of FESS.

关键词： Homopolar inductor machine(HIM) Variable flux Flywheel energy storage system(FESS)

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Time-resolved impact electrochemistry for quantitative measurement of single-nanoparticle reaction kinetics

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Nano Research 2017年第11期10卷 3680-3689页

作者： En Ning Saw Markus Kratz Kristina Tschulik Micro-&Nano-Electrochemistry and Centre for Electrochemical Sciences(ces) Ruhr-University BochumBochum D-44780Germany

Single-nanoparticle electrochemistry has been established as a tool to characterize various nanomaterials based on the charge passed during their random impact at an electrode.Here it is demonstrated that the duration and shape of the resulting current peak can be used to quantify the reaction kinetics on a single-particle basis.Both the chemical rate constant and reaction mechanism for oxidation of single nanoparticles in different electrolytes can be determined directly from the duration of the current signal recorded in high-speed,high-sensitivity current measurements.Using 29-nm-sized Ag particles in four different electrolytes as a proof of concept for this general approach,hitherto inaccessible insights into single-particle reactivity are provided.While comparable rate constants were measured for the four electrolytes at low overpotentials,transport-limited impacts at high overpotentials were found to depend strongly on the type and quantity of anions present in solution.

关键词： single-particle reactivity,electrochemical kinetics,nano-impact method,silver,reaction mechanism

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