As an emerging research field,inductively coupled wireless power transfer(ICWPT) technology has attracted wide spread attention recently.In this paper,the maximum power transfer performances of four basic topologies l...As an emerging research field,inductively coupled wireless power transfer(ICWPT) technology has attracted wide spread attention recently.In this paper,the maximum power transfer performances of four basic topologies labeled as SS,SP,PS and PP are investigated.By modeling the equivalent circuits of these topologies in high frequency(HF),the primary resonance compensation capacitances for maximum power transfer capability are deduced.It is found that these capacitances fluctuate with load resistance change,which is disadvantageous to SP,PS and PP topologies and an obstacle to their practical applications as well.To solve this problem,a phase controlled inductor circuit is proposed.By adjusting the triggering angle,the real-time dynamic tuning control can be achieved to guarantee maximum power transfer.Finally,simulations and experiments show that the proposed method is of great effectiveness and reliability to solve the issue of resonance compensation capacitance fluctuation with load change and to guarantee the flexible applications of all topologies.展开更多
SS型Buck-WPT(Buck-wireless power transfer)系统由Buck电路和基本的SS型无线电能传输电路组成。该电路系统因为结构和控制方式简单、控制效果明显等优点在感应式无线电能传输方面得到广泛应用。但该电路的动态特性并不能满足一些时变...SS型Buck-WPT(Buck-wireless power transfer)系统由Buck电路和基本的SS型无线电能传输电路组成。该电路系统因为结构和控制方式简单、控制效果明显等优点在感应式无线电能传输方面得到广泛应用。但该电路的动态特性并不能满足一些时变系统对快速性的较高要求。例如,系统在启动时会存在较强震荡和较大超调,系统负载改变时稳定状态会发生改变且存在明显抖动,系统极限空载时原边谐振电流会增大,且该电流值远超出安全工作范围。本文提出了一种基于可控电感的SS型Buck-WPT系统。首先,分析了电感值可调的方法并在COMSOL中建立仿真模型验证其电感值可控的特性。其次,对SS型Buck-WPT系统进行数学建模,将SS型WPT系统作为Buck电路的特殊负载,推导SS型Buck-WPT系统状态空间方程。研究其三维空间内相轨迹的降维描述方法,将该系统用二维相轨迹描述系统运行过程。然后,通过分析启动阶段相轨迹运行规律,改进前级Buck电路。将传统Buck电路中的电感换成可控电感,运用其电感值可调的控制系统开通阶段的运行轨迹,使系统在1个开关周期内无超调快速进入稳态。当系统负载改变时,系统的输出电压会改变,且是不断抖动来回反复的过程,利用PI算法对系统进行恒流控制。通过可控电感控制系统相轨迹,使副边输出能无抖动快速进入稳态,保证输出电压不变。针对SS型谐振网络的Buck-WPT系统中出现空载大电流的问题,提出了将可控电感串联接入原边谐振网络的方法。实时检测原边谐振电流值,该值超过正常工作范围,感值就快速增大,减小原边谐振电流,达到空载时维持原边谐振电流安全值以下。最后,验证上述方法在优化SS型Buck-WPT系统动态特性的有效性,在Simulink中搭建仿真电路。该方法能减小工作条件改变时带来的系统抖动,且在不改变系统响应速度前提下减小超调,优化系统动态性能,增强系统抗负载扰动力,提高系统带负载能力有明显效果。展开更多
Gallium nitride(GaN)field-effect transistors have low ON resistance and switching losses in high-frequency(>MHz)resonant wireless power transfer systems.Nevertheless,their performance in the system is determined by...Gallium nitride(GaN)field-effect transistors have low ON resistance and switching losses in high-frequency(>MHz)resonant wireless power transfer systems.Nevertheless,their performance in the system is determined by their characteristics and operation mode.A particular operating mode in a 6.78-MHz magnetic resonant wireless transfer system that employs class-D GaN power amplifiers in the zero-voltage switching mode is studied.Two operation modes,the forward mode and the reverse mode,are investigated.The nonideal effect under the device-level dynamic resistance and thermal effect are also analyzed.The dynamic resistance under different operation modes is demonstrated to have different generation mechanisms.Finally,the device characteristics with system operating conditions are combined,and the effects of temperature and dynamic resistance under different operating conditions are evaluated.展开更多
This article outlines an Effective Method for Automatic Electric Vehicle Charging Stations in a Static Environment. It consists of investigated wireless transformer structures with various ferrite forms. WPT technolog...This article outlines an Effective Method for Automatic Electric Vehicle Charging Stations in a Static Environment. It consists of investigated wireless transformer structures with various ferrite forms. WPT technology has rapidly advanced in the last few years. At kilowatt power levels, the transmission distance grows from a few millimeters to several hundred millimeters with a grid to load efficiency greater than 90%. The improvements have made the WPT more appealing for electric vehicle (EV) charging applications in both static and dynamic charging scenarios. Static and dynamic WEVCS, two of the main applications, are described, and current developments with features from research facilities, academic institutions, and businesses are noted. Additionally, forthcoming concepts based WEVCS are analyzed and examined, including “dynamic” wireless charging systems (WCS). A dynamic wireless power transfer (DWPT) system, which can supply electricity to moving EVs, is one of the feasible alternatives. The moving secondary coil is part of the dynamic WPT system, which also comprises of many fixed groundside (primary) coils. An equivalent circuit between the stationary system and the dynamic WPT system that results from the stationary system is demonstrated by theoretical investigations. The dynamic WPT system’s solenoid coils outperform circular coils in terms of flux distribution and misalignment. The WPT-related EV wireless charging technologies were examined in this study. WPT can assist EVs in overcoming their restrictions on cost, range, and charging time.展开更多
基金supported by the National High-Tech Research & Development Program of China ("863" Program) (Grant No. 2012AA050210)the National Natural Science Foundation of China (Grant No. 51177011)+1 种基金the Research Innovation Program for College Graduates of Jiangsu Province (Grant No. CXZZ11_0150)Scholarship Award for Excellent Doctoral Student granted by Ministry of Education of China
文摘As an emerging research field,inductively coupled wireless power transfer(ICWPT) technology has attracted wide spread attention recently.In this paper,the maximum power transfer performances of four basic topologies labeled as SS,SP,PS and PP are investigated.By modeling the equivalent circuits of these topologies in high frequency(HF),the primary resonance compensation capacitances for maximum power transfer capability are deduced.It is found that these capacitances fluctuate with load resistance change,which is disadvantageous to SP,PS and PP topologies and an obstacle to their practical applications as well.To solve this problem,a phase controlled inductor circuit is proposed.By adjusting the triggering angle,the real-time dynamic tuning control can be achieved to guarantee maximum power transfer.Finally,simulations and experiments show that the proposed method is of great effectiveness and reliability to solve the issue of resonance compensation capacitance fluctuation with load change and to guarantee the flexible applications of all topologies.
文摘SS型Buck-WPT(Buck-wireless power transfer)系统由Buck电路和基本的SS型无线电能传输电路组成。该电路系统因为结构和控制方式简单、控制效果明显等优点在感应式无线电能传输方面得到广泛应用。但该电路的动态特性并不能满足一些时变系统对快速性的较高要求。例如,系统在启动时会存在较强震荡和较大超调,系统负载改变时稳定状态会发生改变且存在明显抖动,系统极限空载时原边谐振电流会增大,且该电流值远超出安全工作范围。本文提出了一种基于可控电感的SS型Buck-WPT系统。首先,分析了电感值可调的方法并在COMSOL中建立仿真模型验证其电感值可控的特性。其次,对SS型Buck-WPT系统进行数学建模,将SS型WPT系统作为Buck电路的特殊负载,推导SS型Buck-WPT系统状态空间方程。研究其三维空间内相轨迹的降维描述方法,将该系统用二维相轨迹描述系统运行过程。然后,通过分析启动阶段相轨迹运行规律,改进前级Buck电路。将传统Buck电路中的电感换成可控电感,运用其电感值可调的控制系统开通阶段的运行轨迹,使系统在1个开关周期内无超调快速进入稳态。当系统负载改变时,系统的输出电压会改变,且是不断抖动来回反复的过程,利用PI算法对系统进行恒流控制。通过可控电感控制系统相轨迹,使副边输出能无抖动快速进入稳态,保证输出电压不变。针对SS型谐振网络的Buck-WPT系统中出现空载大电流的问题,提出了将可控电感串联接入原边谐振网络的方法。实时检测原边谐振电流值,该值超过正常工作范围,感值就快速增大,减小原边谐振电流,达到空载时维持原边谐振电流安全值以下。最后,验证上述方法在优化SS型Buck-WPT系统动态特性的有效性,在Simulink中搭建仿真电路。该方法能减小工作条件改变时带来的系统抖动,且在不改变系统响应速度前提下减小超调,优化系统动态性能,增强系统抗负载扰动力,提高系统带负载能力有明显效果。
基金Supported by the TSV 3D Integrate Micro/Nanosystem Lab(ZDSYS201802061805105)the Natural Science Foundation of Shenzhen(JCYJ20190808155007550)Shenzhen Science Plan(JSGG20180504170016884).
文摘Gallium nitride(GaN)field-effect transistors have low ON resistance and switching losses in high-frequency(>MHz)resonant wireless power transfer systems.Nevertheless,their performance in the system is determined by their characteristics and operation mode.A particular operating mode in a 6.78-MHz magnetic resonant wireless transfer system that employs class-D GaN power amplifiers in the zero-voltage switching mode is studied.Two operation modes,the forward mode and the reverse mode,are investigated.The nonideal effect under the device-level dynamic resistance and thermal effect are also analyzed.The dynamic resistance under different operation modes is demonstrated to have different generation mechanisms.Finally,the device characteristics with system operating conditions are combined,and the effects of temperature and dynamic resistance under different operating conditions are evaluated.
文摘This article outlines an Effective Method for Automatic Electric Vehicle Charging Stations in a Static Environment. It consists of investigated wireless transformer structures with various ferrite forms. WPT technology has rapidly advanced in the last few years. At kilowatt power levels, the transmission distance grows from a few millimeters to several hundred millimeters with a grid to load efficiency greater than 90%. The improvements have made the WPT more appealing for electric vehicle (EV) charging applications in both static and dynamic charging scenarios. Static and dynamic WEVCS, two of the main applications, are described, and current developments with features from research facilities, academic institutions, and businesses are noted. Additionally, forthcoming concepts based WEVCS are analyzed and examined, including “dynamic” wireless charging systems (WCS). A dynamic wireless power transfer (DWPT) system, which can supply electricity to moving EVs, is one of the feasible alternatives. The moving secondary coil is part of the dynamic WPT system, which also comprises of many fixed groundside (primary) coils. An equivalent circuit between the stationary system and the dynamic WPT system that results from the stationary system is demonstrated by theoretical investigations. The dynamic WPT system’s solenoid coils outperform circular coils in terms of flux distribution and misalignment. The WPT-related EV wireless charging technologies were examined in this study. WPT can assist EVs in overcoming their restrictions on cost, range, and charging time.
