Compact accelerator-based neutron source facilities are garnering attention and play an important and expanding role in material and engineering sciences,as well as in neutron science education and training.Neutrons a...Compact accelerator-based neutron source facilities are garnering attention and play an important and expanding role in material and engineering sciences,as well as in neutron science education and training.Neutrons are produced by bombarding a low-energy proton beam onto a beryllium or lithium target.In such an acceleratorbased neutron source,a radio frequency quadrupole(RFQ)is usually utilized to accelerate a high-intensity proton beam to a few MeV.This study mainly covers the highfrequency structure design optimizations of a 4-vane RFQ with pi-mode stabilizer loops(PISLs)and its RF stability analysis.A 176 MHz RFQ accelerator is designed to operate at a 10%duty factor and could accelerate an80 mA proton beam from 65 keV to 2.5 MeV within a length of 5.3 m.The adoption of PISLs ensures high RF stability,eases the operation of the accelerator,and implies less stringent alignment and machining tolerances.展开更多
双向DC-DC变换器是新能源汽车混合动力系统的关键部件,为解决传统比例积分控制下双向DC-DC变换器在动态响应速度与抗干扰能力方面的不足,设计了一种基于前馈变结构比例积分控制(Feedforward Sliding Mode PI Control,FSMPI)的双向DC-DC...双向DC-DC变换器是新能源汽车混合动力系统的关键部件,为解决传统比例积分控制下双向DC-DC变换器在动态响应速度与抗干扰能力方面的不足,设计了一种基于前馈变结构比例积分控制(Feedforward Sliding Mode PI Control,FSMPI)的双向DC-DC变换器控制策略.该策略利用变结构控制对干扰信号的实时信息进行补偿,并结合前馈控制,以增强系统的鲁棒性.为验证所提控制策略的有效性,通过仿真与STM32F4实验平台上的对比实验,评估了其与传统比例积分控制的性能差异.结果表明,在负载变化时,采用前馈变结构比例积分控制的变换器具有更好的动态性能和鲁棒性.展开更多
针对独立光储微电网经常遭受的各种变化和不确定性,提出一种基于滑模的控制策略,以增强对干扰的鲁棒性,改善系统的动态性能。为有效降低外界太阳照射对系统的不利影响,提出一种基于前置DC/DC变换器的非奇异快速终端滑模(non-singular fa...针对独立光储微电网经常遭受的各种变化和不确定性,提出一种基于滑模的控制策略,以增强对干扰的鲁棒性,改善系统的动态性能。为有效降低外界太阳照射对系统的不利影响,提出一种基于前置DC/DC变换器的非奇异快速终端滑模(non-singular fast terminal sliding mode control,NFTSMC)级联电导增量法(incremental conductance method,InC)的方案,控制光伏输出电压跟踪基准电压,从而提高最大功率点跟踪(maximum power point tracking,MPPT)性能;为降低负载变化对系统的不利影响,提出一种基于滑模控制全桥逆变器的控制方案,从而保证系统稳态误差小、动态响应好;为保证直流母线电压稳定,采用传统的双回路PI控制方案实现双向DC/DC变换器,保证系统功率平衡。最后在Matlab/Simulink环境下进行仿真测试,验证控制策略的有效性。展开更多
文摘Compact accelerator-based neutron source facilities are garnering attention and play an important and expanding role in material and engineering sciences,as well as in neutron science education and training.Neutrons are produced by bombarding a low-energy proton beam onto a beryllium or lithium target.In such an acceleratorbased neutron source,a radio frequency quadrupole(RFQ)is usually utilized to accelerate a high-intensity proton beam to a few MeV.This study mainly covers the highfrequency structure design optimizations of a 4-vane RFQ with pi-mode stabilizer loops(PISLs)and its RF stability analysis.A 176 MHz RFQ accelerator is designed to operate at a 10%duty factor and could accelerate an80 mA proton beam from 65 keV to 2.5 MeV within a length of 5.3 m.The adoption of PISLs ensures high RF stability,eases the operation of the accelerator,and implies less stringent alignment and machining tolerances.
文摘双向DC-DC变换器是新能源汽车混合动力系统的关键部件,为解决传统比例积分控制下双向DC-DC变换器在动态响应速度与抗干扰能力方面的不足,设计了一种基于前馈变结构比例积分控制(Feedforward Sliding Mode PI Control,FSMPI)的双向DC-DC变换器控制策略.该策略利用变结构控制对干扰信号的实时信息进行补偿,并结合前馈控制,以增强系统的鲁棒性.为验证所提控制策略的有效性,通过仿真与STM32F4实验平台上的对比实验,评估了其与传统比例积分控制的性能差异.结果表明,在负载变化时,采用前馈变结构比例积分控制的变换器具有更好的动态性能和鲁棒性.
文摘针对独立光储微电网经常遭受的各种变化和不确定性,提出一种基于滑模的控制策略,以增强对干扰的鲁棒性,改善系统的动态性能。为有效降低外界太阳照射对系统的不利影响,提出一种基于前置DC/DC变换器的非奇异快速终端滑模(non-singular fast terminal sliding mode control,NFTSMC)级联电导增量法(incremental conductance method,InC)的方案,控制光伏输出电压跟踪基准电压,从而提高最大功率点跟踪(maximum power point tracking,MPPT)性能;为降低负载变化对系统的不利影响,提出一种基于滑模控制全桥逆变器的控制方案,从而保证系统稳态误差小、动态响应好;为保证直流母线电压稳定,采用传统的双回路PI控制方案实现双向DC/DC变换器,保证系统功率平衡。最后在Matlab/Simulink环境下进行仿真测试,验证控制策略的有效性。
