In the aerospace sector,the soft magnetic materials of Hermetically Sealed Electromagnetic Relays(HSERs)are critical in forming magnetic circuits.Conventional soft magnetic materials,primarily magnetic iron,have been ...In the aerospace sector,the soft magnetic materials of Hermetically Sealed Electromagnetic Relays(HSERs)are critical in forming magnetic circuits.Conventional soft magnetic materials,primarily magnetic iron,have been unable to meet the development trend of fast-response,miniaturized,and lightweight aerospace and aviation systems.This paper applies circuit theory and electromagnetics theory to establish a Field-Circuit Coupling Mathematical Model(FCCMM)for dynamic response analysis of HSERs.This model centers on inductance calculation,with the core's permeability and saturation magnetic flux density as critical parameters.Based on this model,for a specific type of HSER,this paper introduced three alloys with key parameters different from magnetic iron,then tested the magnetic characteristic curves of these four soft magnetic materials,followed by simulations to obtain the electromagnetic characteristics of digital mock-ups corresponding to these four materials,compared and validated the dynamic responses corresponding to these four soft magnetic materials finally.Based on the theoretical model analysis results,this paper designed a lightweight coil to minimize response time,made prototypes,set up test systems,and tested dynamic characteristics.The experimental results indicate that the nanocrystalline alloy1K107B exhibits the most significant optimization,reducing the closing time by 40.48%and achieving a weight reduction of 6.53%.展开更多
Presented field-circuit coupled adaptive time-stepping finite element method to study on permanent magnet linear synchronous motor (PMLSM) characteristics fed by SPWM voltage source inverter.In air-gap field where the...Presented field-circuit coupled adaptive time-stepping finite element method to study on permanent magnet linear synchronous motor (PMLSM) characteristics fed by SPWM voltage source inverter.In air-gap field where the direction or magnitude of the field is changing rapidly,the smallest elements are demanded due to high accuracy to use adaptive meshing technique.The co-simulation was used with the status space functions and time-step finite element functions,in which time-step of the status space functions was the smallest than finite element functions'.The magnitude relation of the normal elec- tromagnetic force and tangential electromagnetic force and the period were attained,and current curve was very abrupt at current zero area due to the bigger resistance and leak- age reactance,including main characteristics of motor voltage and velocity.The simulation results compare triumphantly with the experiments results.展开更多
针对低压交流配电系统中复杂支路串联电弧故障检测困难、易引发电气火灾的挑战,提出了基于马尔可夫变迁场与可变形自引导Transformer(Markov transition field and deformable convolutional self-guided transformer,MTF-DSGT)的检测...针对低压交流配电系统中复杂支路串联电弧故障检测困难、易引发电气火灾的挑战,提出了基于马尔可夫变迁场与可变形自引导Transformer(Markov transition field and deformable convolutional self-guided transformer,MTF-DSGT)的检测方案。利用马尔可夫变迁场将一维电流信号转换为图像,融合可变形卷积网络(deformable convolutional network,DCN)提取局部特征及自引导Transformer捕捉全局信息,以提高故障识别精度。实验结果显示,该方案在复杂支路电路中检测准确率达99.88%,在Jetson Orin Nano平台测试耗时仅7.78 ms。该方案能高效辨识串联电弧故障,具备实时处理能力,适合边缘设备部署。展开更多
In the conventional analogous circuit theory of the loudspeaker system, the vibrating air in box is considered as lumped parameter; in this paper we consider the air as distributed parameter. The sound field theory an...In the conventional analogous circuit theory of the loudspeaker system, the vibrating air in box is considered as lumped parameter; in this paper we consider the air as distributed parameter. The sound field theory and the analogous circuit theory are combined to analyze the characteristics of the loudspeaker system such as radiation acoustic power, frequency response and impedance response.展开更多
基金supported by the National Natural Science Foundation of China(No.52177134)。
文摘In the aerospace sector,the soft magnetic materials of Hermetically Sealed Electromagnetic Relays(HSERs)are critical in forming magnetic circuits.Conventional soft magnetic materials,primarily magnetic iron,have been unable to meet the development trend of fast-response,miniaturized,and lightweight aerospace and aviation systems.This paper applies circuit theory and electromagnetics theory to establish a Field-Circuit Coupling Mathematical Model(FCCMM)for dynamic response analysis of HSERs.This model centers on inductance calculation,with the core's permeability and saturation magnetic flux density as critical parameters.Based on this model,for a specific type of HSER,this paper introduced three alloys with key parameters different from magnetic iron,then tested the magnetic characteristic curves of these four soft magnetic materials,followed by simulations to obtain the electromagnetic characteristics of digital mock-ups corresponding to these four materials,compared and validated the dynamic responses corresponding to these four soft magnetic materials finally.Based on the theoretical model analysis results,this paper designed a lightweight coil to minimize response time,made prototypes,set up test systems,and tested dynamic characteristics.The experimental results indicate that the nanocrystalline alloy1K107B exhibits the most significant optimization,reducing the closing time by 40.48%and achieving a weight reduction of 6.53%.
基金National Natural Sciences Foundation(60474043)Henan Province Science Fund for Distinguished Young Scholars(0412002200)Henan Province Major Projects(0223025300)
文摘Presented field-circuit coupled adaptive time-stepping finite element method to study on permanent magnet linear synchronous motor (PMLSM) characteristics fed by SPWM voltage source inverter.In air-gap field where the direction or magnitude of the field is changing rapidly,the smallest elements are demanded due to high accuracy to use adaptive meshing technique.The co-simulation was used with the status space functions and time-step finite element functions,in which time-step of the status space functions was the smallest than finite element functions'.The magnitude relation of the normal elec- tromagnetic force and tangential electromagnetic force and the period were attained,and current curve was very abrupt at current zero area due to the bigger resistance and leak- age reactance,including main characteristics of motor voltage and velocity.The simulation results compare triumphantly with the experiments results.
文摘针对低压交流配电系统中复杂支路串联电弧故障检测困难、易引发电气火灾的挑战,提出了基于马尔可夫变迁场与可变形自引导Transformer(Markov transition field and deformable convolutional self-guided transformer,MTF-DSGT)的检测方案。利用马尔可夫变迁场将一维电流信号转换为图像,融合可变形卷积网络(deformable convolutional network,DCN)提取局部特征及自引导Transformer捕捉全局信息,以提高故障识别精度。实验结果显示,该方案在复杂支路电路中检测准确率达99.88%,在Jetson Orin Nano平台测试耗时仅7.78 ms。该方案能高效辨识串联电弧故障,具备实时处理能力,适合边缘设备部署。
文摘In the conventional analogous circuit theory of the loudspeaker system, the vibrating air in box is considered as lumped parameter; in this paper we consider the air as distributed parameter. The sound field theory and the analogous circuit theory are combined to analyze the characteristics of the loudspeaker system such as radiation acoustic power, frequency response and impedance response.
