针对在接收端采用混合精度的数模转换器(analog-to-digital converter,ADC)的大规模MIMO系统上行链路,提出一种能效优化算法。在采用最大比合并(maximum ratio combining,MRC)检测算法的基础上,推导得到系统上行链路能效的近似闭式表达...针对在接收端采用混合精度的数模转换器(analog-to-digital converter,ADC)的大规模MIMO系统上行链路,提出一种能效优化算法。在采用最大比合并(maximum ratio combining,MRC)检测算法的基础上,推导得到系统上行链路能效的近似闭式表达式。首先确定高精度ADC的占比率,再以低分辨率ADC的量化精度、用户的发射功率和基站端天线数为优化目标的3个变量进行交替迭代得出最优的能效值;并进一步通过调整高精度ADC的占比率分析其对能效和频效的影响。仿真结果表明,所提算法具有较高的能效值,并且可以通过调整占比率实现能效与频效更好地折中。展开更多
采用多拾取模块并联输出的动态感应电能传输(Inductive power transfer,IPT)系统提高了系统的功率传输能力,适用于长轨式的发射结构,在大功率场合有着广泛的应用前景。但由于拾取模块间参数的微小差异以及模块的动态运行,实际的应用过...采用多拾取模块并联输出的动态感应电能传输(Inductive power transfer,IPT)系统提高了系统的功率传输能力,适用于长轨式的发射结构,在大功率场合有着广泛的应用前景。但由于拾取模块间参数的微小差异以及模块的动态运行,实际的应用过程中会出现拾取模块电流分配不平衡的现象,甚至会导致拾取模块过流损坏。从LCC-S的数学模型出发,推导了拾取模块的输出伏安特性与负载分配特性,分析了不同补偿状态下拾取参数对电流分配的影响,并据此提出一种副边失谐补偿的方案。给出了失谐系数的参数设计方法,利用了对副边参数的调节,实现各个模块的近似均流控制。最后,搭建了一台三个拾取模块并联输出的试验样机,应用所提的失谐补偿方法后,模块间最大电流比例由13.02降低到1.3。试验结果与理论分析一致,证明了所提方案的正确性与有效性。展开更多
Design method of split planar resonant inductor in 1 kV SiC logical link control(LLC)converter is proposed,which ensures the converter power density of 93.59 W/in^3 and peak efficiency of 95.73%.Split resonant inducto...Design method of split planar resonant inductor in 1 kV SiC logical link control(LLC)converter is proposed,which ensures the converter power density of 93.59 W/in^3 and peak efficiency of 95.73%.Split resonant inductor helps to provide symmetrical resonant current by symmetrical impedance,and improves the distortion of resonant current,which ensures the efficiency of the whole converter.An interleaved winding connecting scheme improves the power density of the planar magnets,which contributes to power density improvement.Design method and calculation process of such split planar resonant inductor are provided.To verify the feasibility of the proposed design method,a 1 kV/48 V 6.6 kW,210 k Hz SiC LLC prototype was built,and the experimental results are given.展开更多
The Vienna rectifier with unbalanced input voltage and load transient is analyzed.A nonlinear control strategy for Vienna rectifier under unbalanced input is proposed.From the view of positive and negative sequence co...The Vienna rectifier with unbalanced input voltage and load transient is analyzed.A nonlinear control strategy for Vienna rectifier under unbalanced input is proposed.From the view of positive and negative sequence components,the proposed nonlinear control strategy suppresses the twice frequency ripple and guarantees the dynamic response characteristic at the same time.Thanks to the proposed nonlinear control strategy,the DC bus capacitor can be reduced a lot since the voltage ripple and drop can be suppressed.A 10 kW Vienna rectifier is built to verify the proposed control strategy.After applying the proposed nonlinear control strategy,the voltage ripple is only7 V and decreases over 75%over the traditional PI control when the unbalanced degree is 20%.The voltage drop can be reduced about 80%than former control strategy which is helpful to reduce the DC bus capacitor and achieve higher power density.The volume of the capacitor can be reduced by 83.3%with the new control method.展开更多
This paper presents a cascode configuration synchronous rectifier device based on silicon MOSFET and Schottky diode,which can replace traditional power diode directly.This structure has self-driven ability with simple...This paper presents a cascode configuration synchronous rectifier device based on silicon MOSFET and Schottky diode,which can replace traditional power diode directly.This structure has self-driven ability with simple external circuit,and the conduction characteristic is preferable to a power diode.Static characterization and switching behavior analysis of proposed structure are conducted in this paper.The switching process is illustrated in detail using real model which considers the parasitic inductances and the nonlinearity of junction capacitors.The real time internal voltage and current value during switching transition are deduced with the equivalent circuit.To validate the analysis,two voltage specification rectifiers are built.Finally,double-pulse test results and the practical design example verify the performance advantages of proposed structure.展开更多
文摘针对在接收端采用混合精度的数模转换器(analog-to-digital converter,ADC)的大规模MIMO系统上行链路,提出一种能效优化算法。在采用最大比合并(maximum ratio combining,MRC)检测算法的基础上,推导得到系统上行链路能效的近似闭式表达式。首先确定高精度ADC的占比率,再以低分辨率ADC的量化精度、用户的发射功率和基站端天线数为优化目标的3个变量进行交替迭代得出最优的能效值;并进一步通过调整高精度ADC的占比率分析其对能效和频效的影响。仿真结果表明,所提算法具有较高的能效值,并且可以通过调整占比率实现能效与频效更好地折中。
文摘采用多拾取模块并联输出的动态感应电能传输(Inductive power transfer,IPT)系统提高了系统的功率传输能力,适用于长轨式的发射结构,在大功率场合有着广泛的应用前景。但由于拾取模块间参数的微小差异以及模块的动态运行,实际的应用过程中会出现拾取模块电流分配不平衡的现象,甚至会导致拾取模块过流损坏。从LCC-S的数学模型出发,推导了拾取模块的输出伏安特性与负载分配特性,分析了不同补偿状态下拾取参数对电流分配的影响,并据此提出一种副边失谐补偿的方案。给出了失谐系数的参数设计方法,利用了对副边参数的调节,实现各个模块的近似均流控制。最后,搭建了一台三个拾取模块并联输出的试验样机,应用所提的失谐补偿方法后,模块间最大电流比例由13.02降低到1.3。试验结果与理论分析一致,证明了所提方案的正确性与有效性。
基金supported by the National Key Research and Development Program of China (2018YFB0904101)Science and Technology Project of State Grid (SG SGHB0000KXJS1800685)
文摘Design method of split planar resonant inductor in 1 kV SiC logical link control(LLC)converter is proposed,which ensures the converter power density of 93.59 W/in^3 and peak efficiency of 95.73%.Split resonant inductor helps to provide symmetrical resonant current by symmetrical impedance,and improves the distortion of resonant current,which ensures the efficiency of the whole converter.An interleaved winding connecting scheme improves the power density of the planar magnets,which contributes to power density improvement.Design method and calculation process of such split planar resonant inductor are provided.To verify the feasibility of the proposed design method,a 1 kV/48 V 6.6 kW,210 k Hz SiC LLC prototype was built,and the experimental results are given.
基金supported in part by the National Natural Science Foundation of China (Nos. 51777093 ,51722702)
文摘The Vienna rectifier with unbalanced input voltage and load transient is analyzed.A nonlinear control strategy for Vienna rectifier under unbalanced input is proposed.From the view of positive and negative sequence components,the proposed nonlinear control strategy suppresses the twice frequency ripple and guarantees the dynamic response characteristic at the same time.Thanks to the proposed nonlinear control strategy,the DC bus capacitor can be reduced a lot since the voltage ripple and drop can be suppressed.A 10 kW Vienna rectifier is built to verify the proposed control strategy.After applying the proposed nonlinear control strategy,the voltage ripple is only7 V and decreases over 75%over the traditional PI control when the unbalanced degree is 20%.The voltage drop can be reduced about 80%than former control strategy which is helpful to reduce the DC bus capacitor and achieve higher power density.The volume of the capacitor can be reduced by 83.3%with the new control method.
基金supported in part by the National Natural Science Foundation of China (No.51777093)
文摘This paper presents a cascode configuration synchronous rectifier device based on silicon MOSFET and Schottky diode,which can replace traditional power diode directly.This structure has self-driven ability with simple external circuit,and the conduction characteristic is preferable to a power diode.Static characterization and switching behavior analysis of proposed structure are conducted in this paper.The switching process is illustrated in detail using real model which considers the parasitic inductances and the nonlinearity of junction capacitors.The real time internal voltage and current value during switching transition are deduced with the equivalent circuit.To validate the analysis,two voltage specification rectifiers are built.Finally,double-pulse test results and the practical design example verify the performance advantages of proposed structure.
