Due to a series of challenges such as low-orbit maintenance of satellites, the air-breathing electric propulsion has got widespread attention. Commonly, the radio frequency ion thruster is favored by low-orbit mission...Due to a series of challenges such as low-orbit maintenance of satellites, the air-breathing electric propulsion has got widespread attention. Commonly, the radio frequency ion thruster is favored by low-orbit missions due to its high specific impulse and efficiency. In this paper, the power transfer efficiency of the radio frequency ion thruster with different gas compositions is studied experimentally, which is obtained by measuring the radio frequency power and current of the antenna coil with and without discharge operation. The results show that increasing the turns of antenna coils can effectively improve the radio frequency power transfer efficiency, which is due to the improvement of Q factor. In pure N_2 discharge,with the increase of radio frequency power, the radio frequency power transfer efficiency first rises rapidly and then exhibits a less steep increasing trend. The radio frequency power transfer efficiency increases with the increase of gas pressure at relatively high power, while declines rapidly at relatively low power. In N_(2)/O_(2) discharge, increasing the N_(2) content at high power can improve the radio frequency power transfer efficiency, but the opposite was observed at low power. In order to give a better understanding of these trends, an analytic solution in limit cases is utilized, and a Langmuir probe was employed to measure the electron density. It is found that the evolution of radio frequency power transfer efficiency can be well explained by the variation of plasma resistance, which is related to the electron density and the effective electron collision frequency.展开更多
Traditional power supply method for moving electric railway vehicles is based on contact type power collection technology.This sometimes cannot meet the requirements of modern rail transportation.A new wireless power ...Traditional power supply method for moving electric railway vehicles is based on contact type power collection technology.This sometimes cannot meet the requirements of modern rail transportation.A new wireless power transfer(WPT)technology can offer significant benefits in modern rail transportation particularly in some stringent environments.This paper reviews the status and the development of rail transit power supply technology,and introduces a new challenging technology--inductive power transfer(IPT)technology for rail transit.Tesla established the underpinning of IPT technology and creatively and significantly demonstrated power transfer by using highly resonant tuned coils long time ago.However,only in recent years the IPT technology has been significantly improved including the transfer air-gap length,transfer efficiency,coupling factor,power transfer capability and so on.This is mainly due to innovative semiconductor switches,higher control frequency,better coil designs and high performance material,new track and vehicle construction techniques.Recent advances in IPT for rail transit and major milestones of the developments are summarized in this paper.Some important technical issues such as coupling coil structures,power supply schemes,segmentation switching techniques for long-distance power supply,and bidirectional IPT systems for braking energy feedback are discussed.展开更多
Along with the prosperous of magnetic coupled inductive power transfer( MCIPT) technology which is widely used in industrial applications such as electric vehicle charging,the topology of double D coils( DD coils) wit...Along with the prosperous of magnetic coupled inductive power transfer( MCIPT) technology which is widely used in industrial applications such as electric vehicle charging,the topology of double D coils( DD coils) with a spatial quadrature Q coil arises with great research interest. The Q coil, however, has been thoroughly studied by adding to the receiving side but seldom to the transmitting side. By using finite element simulation, this paper presents a preliminary study on the effectiveness of Q coil in the transmitting side,and its inner dimension is optimized for optimal compensating the misalignment between the transmitting and receiver sides. Simulation results show that the windings of the Q coil should be placed in the center of the aperture of the DD coils,and these results render a useful guidance for mechanical structural design and circuit controller design of MCIPT.展开更多
Inductively coupled power transfer systems (ICPT) are becoming ubiquitous in industry. Many such systems are excited with single or multi-phase input current. This leads to increased complexity in comparing such syste...Inductively coupled power transfer systems (ICPT) are becoming ubiquitous in industry. Many such systems are excited with single or multi-phase input current. This leads to increased complexity in comparing such systems when solely using the magnetic frequency analysis. This paper utilizes modern finite element method analysis software to propose a novel software methodology for the numerical comparison of single and two phase ICPT systems as demonstrated on a three dimensional (3D) battery charging system. The sinusoidal magnetic frequency response of a single phase system is compared to the magnetic transient response of a multi-phase current system by use of a novel software methodology proposed in this paper. This consists of a transient response analysis to determine compute the resulting magnetic response over the duration of an input current period on the two phase system. The resulting non-sinusoidal response is then integrated over a whole period to extract the root-mean-square value for comparison with that of a single phase system across a 3D cubic power zone.展开更多
In this paper,a novel pulse density modulation(PDM)with semi-bridgeless active rectifier(S-BAR)in inductive power transfer(IPT)system for rail vehicle is proposed.It is to reduce switching losses of the active rectifi...In this paper,a novel pulse density modulation(PDM)with semi-bridgeless active rectifier(S-BAR)in inductive power transfer(IPT)system for rail vehicle is proposed.It is to reduce switching losses of the active rectifier in pickups.In the control method,the insulated-gate bipolar transistors(IGBTs)in the S-BAR are controlled by synchronous PDM signals,so that zero-voltage switching(ZVS)and zero-current switching(ZCS)can be achieved in the whole output power range.The output power is regulated by changing the pulse density(PD)of the S-BAR since the it is almost linear proportional with the PD in high quality factor of pickup side.The communication device between the primary side and pickup side is not necessary anymore.The detailed theoretical analyses of the PDM method are provided,and its advantages are shown in a 7.5kW IPT prototype for rail vehicle.The experimental results are presented to verify the analysis and demonstrate the performance.The overall efficiency of the system by PDM control is 74.2%which is improved by 4%compared with phase shift(PS)control at light load.展开更多
与传统接触式充电方式相比,采用感应式电能传输IPT(inductive power transfer)系统给自主水下航行器AUVs(autonomous underwater vehicles)充电更加方便和安全。为了解决AUV船体中心磁场强和由波浪引起的旋转偏移导致传输功率剧烈波动...与传统接触式充电方式相比,采用感应式电能传输IPT(inductive power transfer)系统给自主水下航行器AUVs(autonomous underwater vehicles)充电更加方便和安全。为了解决AUV船体中心磁场强和由波浪引起的旋转偏移导致传输功率剧烈波动的问题,提出1种具有新型耦合结构的三相IPT系统。耦合器由3个发射线圈和4个反向交替串联的接收线圈组成,该结构有利于抑制中心磁场并提高抗旋转偏移性能。Maxwell仿真结果表明,在船体旋转时,等效互感Meq波动小于2%,同时AUV中心磁场始终保持在较低水平。此外,为简化系统分析,采用1种无源元件解耦的方法对3个发射线圈进行解耦。搭建了1台基于LCC-S补偿拓扑的实验样机来验证系统的可行性,实验结果表明,当AUV旋转时,传输功率为536~595 W,最大波动率为9.91%,系统直-直最高效率为86.28%。展开更多
Wireless power transfer via inductive link is becoming a popular choice as an alternate powering scheme for biomedical sensor electronics. Spiral printed circuit board (PCB) inductors are gaining attractions for wirel...Wireless power transfer via inductive link is becoming a popular choice as an alternate powering scheme for biomedical sensor electronics. Spiral printed circuit board (PCB) inductors are gaining attractions for wireless power transfer applications due to their various advantages over conventional inductors such as low-cost, batch fabrication, durability, manufacturability on flexible substrates, etc. In this work, design of a multi-spiral stacked solenoidal inductor for biomedical application in 13.56 MHz band is presented. Proposed stacking method enhances the inductance density of the inductor for a given area. This paper reports an optimization technique for design and implementation of the PCB inductors. The proposed scheme shows higher inductance and better figure-of-merit values compared to PCB inductors reported in literature, which are desirable for wireless power transfer system.展开更多
By representing the Earth as a rotating spherical antenna several historic and scientific breakthroughs are achieved.Visualizing the Sun as a transmitter and the planets as receivers the solar system can be represente...By representing the Earth as a rotating spherical antenna several historic and scientific breakthroughs are achieved.Visualizing the Sun as a transmitter and the planets as receivers the solar system can be represented as a long wave radio system operating at Tremendously Low Frequency(TLF).Results again confirm that the“near-field”is Tesla’s“dynamic gravity”,better known to engineers as dynamic braking or to physicists as centripetal acceleration,or simply(g).Timewave theory is invented,and the relationship of reflected timewaves and time travel explored.A new law of the Sun is proposed as well as the merging of Einstein’s equation with acoustics and cosmic superstring theory.A new law of cosmic efficiency is also proposed that equates vibratory force and pressure with volume acceleration of the solar system.Lorentz force is broken down into centripetal and gravitational waves.Ten-dimensional cosmic superstring theory is espoused versus the aging three-dimensional Maxwellian model.Spherical antenna patterns for planets are presented and flux transfer frequency is calculated using distance to planets as wavelengths.The galactic grid operates at a Schumann Resonance of 7.83 Hz,which is derived from the science of dark energy and dark matter.The Sun and the planets are tuned to transmit and receive electrical power like resonating Tesla coils.The Earth’s stator winding has been modeled as a toroid tesla coil and the armature as a spherical armature.The equation for everything is born.展开更多
传统的感应电能传输(inductive power transfer,IPT)系统采用单相全桥谐振逆变器,由于受到功率器件的容量限制,IPT系统的输出功率较低。为实现IPT系统大功率输出,构建了基于阶梯波移相合成方法的级联型多电平逆变器的IPT系统,并详细分...传统的感应电能传输(inductive power transfer,IPT)系统采用单相全桥谐振逆变器,由于受到功率器件的容量限制,IPT系统的输出功率较低。为实现IPT系统大功率输出,构建了基于阶梯波移相合成方法的级联型多电平逆变器的IPT系统,并详细分析其工作原理和功率自平衡特性。在此基础上,建立谐波消除方程,得到移相角与脉宽的显式解,从而避免求解高次超越方程。在消除3次谐波的基础上,通过改变移相角与脉宽,不需增加DC-DC环节便能实现IPT系统输出功率的连续调节。仿真和实验验证了IPT系统的级联型逆变器输出功率为1.6 kW时,每个全桥单元的输出功率约为800 W,且级联逆变器的输出电压的3次谐波被完全消除,同时能连续调节IPT系统的功率。这种基于阶梯波移相合成方法的级联型多电平逆变器可望在大功率IPT系统中得到应用。展开更多
为了简化感应电能传输(inductive power transfer,IPT)电池充电系统原边与副边电路的设计和控制复杂性,该文提出通过在原边电路加入一个附加电容和一个半导体开关的方法实现对电池恒流恒压切换充电,无需调节逆变器直流输入电压、原边移...为了简化感应电能传输(inductive power transfer,IPT)电池充电系统原边与副边电路的设计和控制复杂性,该文提出通过在原边电路加入一个附加电容和一个半导体开关的方法实现对电池恒流恒压切换充电,无需调节逆变器直流输入电压、原边移相控制及副边加入调压电路。恒流模式时,配置的补偿电容完全补偿原边线圈;恒压模式时,只需一个开关切出或者切入附加电容。该方法只需简单的通信(用于充电模式切换),没有复杂的控制策略,结构简单,成本低。实验表明,所提出方法输出的恒流和恒压随着电池等效负载电阻改变而轻微变化,但结果仍然满足电池充电要求。展开更多
为实现感应电能传输(inductivepowertransfer,IPT)系统在负载变化下的恒定电压和高效电能输出,提出一种基于线性自抗扰控制(linear active disturbance rejection control,LADRC)的恒压输出和基于阻抗匹配技术的最大效率跟踪的复合控制...为实现感应电能传输(inductivepowertransfer,IPT)系统在负载变化下的恒定电压和高效电能输出,提出一种基于线性自抗扰控制(linear active disturbance rejection control,LADRC)的恒压输出和基于阻抗匹配技术的最大效率跟踪的复合控制方法。首先,分析LCC-S型IPT系统的参数与效率、输出功率的关系,通过参数优化设计使最优效率达到最大化;然后,在副边采用基于Buck-Boost电路的阻抗匹配技术以实现最大效率跟踪,同时在原边设计一阶LADRC对输出电压进行闭环控制,并给出控制器参数选取规则,所提复合控制方法保证效率和电压2个控制回路之间的解耦运行;最后,搭建实验平台对理论分析进行验证。实验结果表明,当负载电阻从满载到轻载变化时,所提系统可以实现恒压输出,整体效率保持在85.7%,与比例积分控制相比,LADRC对负载扰动和参考电压扰动具有更好的输出电压动态调节作用。展开更多
在电池充电中,感应电能传输(inductive power transfer,IPT)系统通常需要实现恒流(constant current,CC)和恒压(constant voltage,CV)输出。同时,IPT系统的线圈偏移是难以避免的,因此系统同时需要具有抗偏移能力。文中提出一种基于混合...在电池充电中,感应电能传输(inductive power transfer,IPT)系统通常需要实现恒流(constant current,CC)和恒压(constant voltage,CV)输出。同时,IPT系统的线圈偏移是难以避免的,因此系统同时需要具有抗偏移能力。文中提出一种基于混合钳位拓扑的IPT系统,利用钳位电路实现CC到CV的自动切换,通过四线圈结构的混合拓扑提高系统的抗偏移性能,简化系统控制复杂性。最后,搭建一个400 W的原理样机,验证所提方法的正确性和有效性。负载在5~100Ω范围变化时,系统在X轴方向偏移达52.5%和Z轴方向偏移为17.5%的情况下,CC模式下的输出电流和CV模式下的输出电压波动始终小于5%。展开更多
针对感应电能传输(inductive power transfer,IPT)系统多负载条件下能量传输效率问题研究频率与效率的关系,并从系统能量流动的角度解释效率特性。为了验证最大传输效率结论的正确性,采用双工作模式切换的电流调节方法和离散准滑模控制...针对感应电能传输(inductive power transfer,IPT)系统多负载条件下能量传输效率问题研究频率与效率的关系,并从系统能量流动的角度解释效率特性。为了验证最大传输效率结论的正确性,采用双工作模式切换的电流调节方法和离散准滑模控制策略来维持原边谐振电流(激磁电流)的恒定。基于系统能量平衡函数关系,建立关于激磁电流峰值包络的系统离散变结构模型,构建具有重置积分环节的切换函数来改善系统的稳态响应。实验结果表明,当工作频率偏离副边固有谐振频率时,系统效率最大,合理的积分增益可以使系统具有较好的控制性能,对于负载大范围变化具有较强的鲁棒性,如当负载完全拿开时,控制器经过时长约为5 ms的调节,激磁电流最终稳定在参考值,表现出较好的抗扰动性,且系统效率均保持90%以上。展开更多
基金Project supported by the National Natural Science Foundation of China(Grant Nos.12005031 and 12275041)the Natural Science Fund from the Interdisciplinary Project of Dalian University(Grant No.DLUXK-2023-QN-001)。
文摘Due to a series of challenges such as low-orbit maintenance of satellites, the air-breathing electric propulsion has got widespread attention. Commonly, the radio frequency ion thruster is favored by low-orbit missions due to its high specific impulse and efficiency. In this paper, the power transfer efficiency of the radio frequency ion thruster with different gas compositions is studied experimentally, which is obtained by measuring the radio frequency power and current of the antenna coil with and without discharge operation. The results show that increasing the turns of antenna coils can effectively improve the radio frequency power transfer efficiency, which is due to the improvement of Q factor. In pure N_2 discharge,with the increase of radio frequency power, the radio frequency power transfer efficiency first rises rapidly and then exhibits a less steep increasing trend. The radio frequency power transfer efficiency increases with the increase of gas pressure at relatively high power, while declines rapidly at relatively low power. In N_(2)/O_(2) discharge, increasing the N_(2) content at high power can improve the radio frequency power transfer efficiency, but the opposite was observed at low power. In order to give a better understanding of these trends, an analytic solution in limit cases is utilized, and a Langmuir probe was employed to measure the electron density. It is found that the evolution of radio frequency power transfer efficiency can be well explained by the variation of plasma resistance, which is related to the electron density and the effective electron collision frequency.
基金This work was supported in part by the National Key R&D Program of China under Grant 2017YFB1201003.
文摘Traditional power supply method for moving electric railway vehicles is based on contact type power collection technology.This sometimes cannot meet the requirements of modern rail transportation.A new wireless power transfer(WPT)technology can offer significant benefits in modern rail transportation particularly in some stringent environments.This paper reviews the status and the development of rail transit power supply technology,and introduces a new challenging technology--inductive power transfer(IPT)technology for rail transit.Tesla established the underpinning of IPT technology and creatively and significantly demonstrated power transfer by using highly resonant tuned coils long time ago.However,only in recent years the IPT technology has been significantly improved including the transfer air-gap length,transfer efficiency,coupling factor,power transfer capability and so on.This is mainly due to innovative semiconductor switches,higher control frequency,better coil designs and high performance material,new track and vehicle construction techniques.Recent advances in IPT for rail transit and major milestones of the developments are summarized in this paper.Some important technical issues such as coupling coil structures,power supply schemes,segmentation switching techniques for long-distance power supply,and bidirectional IPT systems for braking energy feedback are discussed.
基金Sichuan International Exchange of Science and Technology Cooperation and Research Program,China(No.2015HH0010)
文摘Along with the prosperous of magnetic coupled inductive power transfer( MCIPT) technology which is widely used in industrial applications such as electric vehicle charging,the topology of double D coils( DD coils) with a spatial quadrature Q coil arises with great research interest. The Q coil, however, has been thoroughly studied by adding to the receiving side but seldom to the transmitting side. By using finite element simulation, this paper presents a preliminary study on the effectiveness of Q coil in the transmitting side,and its inner dimension is optimized for optimal compensating the misalignment between the transmitting and receiver sides. Simulation results show that the windings of the Q coil should be placed in the center of the aperture of the DD coils,and these results render a useful guidance for mechanical structural design and circuit controller design of MCIPT.
文摘Inductively coupled power transfer systems (ICPT) are becoming ubiquitous in industry. Many such systems are excited with single or multi-phase input current. This leads to increased complexity in comparing such systems when solely using the magnetic frequency analysis. This paper utilizes modern finite element method analysis software to propose a novel software methodology for the numerical comparison of single and two phase ICPT systems as demonstrated on a three dimensional (3D) battery charging system. The sinusoidal magnetic frequency response of a single phase system is compared to the magnetic transient response of a multi-phase current system by use of a novel software methodology proposed in this paper. This consists of a transient response analysis to determine compute the resulting magnetic response over the duration of an input current period on the two phase system. The resulting non-sinusoidal response is then integrated over a whole period to extract the root-mean-square value for comparison with that of a single phase system across a 3D cubic power zone.
文摘In this paper,a novel pulse density modulation(PDM)with semi-bridgeless active rectifier(S-BAR)in inductive power transfer(IPT)system for rail vehicle is proposed.It is to reduce switching losses of the active rectifier in pickups.In the control method,the insulated-gate bipolar transistors(IGBTs)in the S-BAR are controlled by synchronous PDM signals,so that zero-voltage switching(ZVS)and zero-current switching(ZCS)can be achieved in the whole output power range.The output power is regulated by changing the pulse density(PD)of the S-BAR since the it is almost linear proportional with the PD in high quality factor of pickup side.The communication device between the primary side and pickup side is not necessary anymore.The detailed theoretical analyses of the PDM method are provided,and its advantages are shown in a 7.5kW IPT prototype for rail vehicle.The experimental results are presented to verify the analysis and demonstrate the performance.The overall efficiency of the system by PDM control is 74.2%which is improved by 4%compared with phase shift(PS)control at light load.
文摘Wireless power transfer via inductive link is becoming a popular choice as an alternate powering scheme for biomedical sensor electronics. Spiral printed circuit board (PCB) inductors are gaining attractions for wireless power transfer applications due to their various advantages over conventional inductors such as low-cost, batch fabrication, durability, manufacturability on flexible substrates, etc. In this work, design of a multi-spiral stacked solenoidal inductor for biomedical application in 13.56 MHz band is presented. Proposed stacking method enhances the inductance density of the inductor for a given area. This paper reports an optimization technique for design and implementation of the PCB inductors. The proposed scheme shows higher inductance and better figure-of-merit values compared to PCB inductors reported in literature, which are desirable for wireless power transfer system.
文摘By representing the Earth as a rotating spherical antenna several historic and scientific breakthroughs are achieved.Visualizing the Sun as a transmitter and the planets as receivers the solar system can be represented as a long wave radio system operating at Tremendously Low Frequency(TLF).Results again confirm that the“near-field”is Tesla’s“dynamic gravity”,better known to engineers as dynamic braking or to physicists as centripetal acceleration,or simply(g).Timewave theory is invented,and the relationship of reflected timewaves and time travel explored.A new law of the Sun is proposed as well as the merging of Einstein’s equation with acoustics and cosmic superstring theory.A new law of cosmic efficiency is also proposed that equates vibratory force and pressure with volume acceleration of the solar system.Lorentz force is broken down into centripetal and gravitational waves.Ten-dimensional cosmic superstring theory is espoused versus the aging three-dimensional Maxwellian model.Spherical antenna patterns for planets are presented and flux transfer frequency is calculated using distance to planets as wavelengths.The galactic grid operates at a Schumann Resonance of 7.83 Hz,which is derived from the science of dark energy and dark matter.The Sun and the planets are tuned to transmit and receive electrical power like resonating Tesla coils.The Earth’s stator winding has been modeled as a toroid tesla coil and the armature as a spherical armature.The equation for everything is born.
文摘传统的感应电能传输(inductive power transfer,IPT)系统采用单相全桥谐振逆变器,由于受到功率器件的容量限制,IPT系统的输出功率较低。为实现IPT系统大功率输出,构建了基于阶梯波移相合成方法的级联型多电平逆变器的IPT系统,并详细分析其工作原理和功率自平衡特性。在此基础上,建立谐波消除方程,得到移相角与脉宽的显式解,从而避免求解高次超越方程。在消除3次谐波的基础上,通过改变移相角与脉宽,不需增加DC-DC环节便能实现IPT系统输出功率的连续调节。仿真和实验验证了IPT系统的级联型逆变器输出功率为1.6 kW时,每个全桥单元的输出功率约为800 W,且级联逆变器的输出电压的3次谐波被完全消除,同时能连续调节IPT系统的功率。这种基于阶梯波移相合成方法的级联型多电平逆变器可望在大功率IPT系统中得到应用。
文摘为了简化感应电能传输(inductive power transfer,IPT)电池充电系统原边与副边电路的设计和控制复杂性,该文提出通过在原边电路加入一个附加电容和一个半导体开关的方法实现对电池恒流恒压切换充电,无需调节逆变器直流输入电压、原边移相控制及副边加入调压电路。恒流模式时,配置的补偿电容完全补偿原边线圈;恒压模式时,只需一个开关切出或者切入附加电容。该方法只需简单的通信(用于充电模式切换),没有复杂的控制策略,结构简单,成本低。实验表明,所提出方法输出的恒流和恒压随着电池等效负载电阻改变而轻微变化,但结果仍然满足电池充电要求。
文摘为实现感应电能传输(inductivepowertransfer,IPT)系统在负载变化下的恒定电压和高效电能输出,提出一种基于线性自抗扰控制(linear active disturbance rejection control,LADRC)的恒压输出和基于阻抗匹配技术的最大效率跟踪的复合控制方法。首先,分析LCC-S型IPT系统的参数与效率、输出功率的关系,通过参数优化设计使最优效率达到最大化;然后,在副边采用基于Buck-Boost电路的阻抗匹配技术以实现最大效率跟踪,同时在原边设计一阶LADRC对输出电压进行闭环控制,并给出控制器参数选取规则,所提复合控制方法保证效率和电压2个控制回路之间的解耦运行;最后,搭建实验平台对理论分析进行验证。实验结果表明,当负载电阻从满载到轻载变化时,所提系统可以实现恒压输出,整体效率保持在85.7%,与比例积分控制相比,LADRC对负载扰动和参考电压扰动具有更好的输出电压动态调节作用。
文摘针对感应电能传输(inductive power transfer,IPT)系统多负载条件下能量传输效率问题研究频率与效率的关系,并从系统能量流动的角度解释效率特性。为了验证最大传输效率结论的正确性,采用双工作模式切换的电流调节方法和离散准滑模控制策略来维持原边谐振电流(激磁电流)的恒定。基于系统能量平衡函数关系,建立关于激磁电流峰值包络的系统离散变结构模型,构建具有重置积分环节的切换函数来改善系统的稳态响应。实验结果表明,当工作频率偏离副边固有谐振频率时,系统效率最大,合理的积分增益可以使系统具有较好的控制性能,对于负载大范围变化具有较强的鲁棒性,如当负载完全拿开时,控制器经过时长约为5 ms的调节,激磁电流最终稳定在参考值,表现出较好的抗扰动性,且系统效率均保持90%以上。
