提出一种全桥双谐振CLL谐振DC-DC变换器拓扑。该变换器有两个谐振网络,共用一个变压器。该谐振变换器能在全负载范围内,实现开关管的零电压导通ZVS(zero voltage switching)和副边整流二极管的零电流关断ZCS(zero current switching),...提出一种全桥双谐振CLL谐振DC-DC变换器拓扑。该变换器有两个谐振网络,共用一个变压器。该谐振变换器能在全负载范围内,实现开关管的零电压导通ZVS(zero voltage switching)和副边整流二极管的零电流关断ZCS(zero current switching),变换器开关管的开关损耗低,同时消除了二极管的反向恢复损耗,实现较高效率,适用于分布式电源系统中的直直变换模块。采用基波分析FHA(fundamental harmonic approximation)方法对该谐振变换器进行分析,得到了该变换器的直流增益特性。最后,制作了一台200 W的实验样机,验证了理论分析的正确性。展开更多
A theoretical model for irreversible double resonance ESE(energy selective electron) device with phonon induced bypass heat leakage which is operating as heat engine system is proposed. The thermodynamic performance i...A theoretical model for irreversible double resonance ESE(energy selective electron) device with phonon induced bypass heat leakage which is operating as heat engine system is proposed. The thermodynamic performance is optimized and the impacts of heat leakage and structure parameters of the electron system on its performance are discussed in detail by using FTT(finite time thermodynamics). Moreover, performances of the ESE system with multiple optimization objective functions, including power output, thermal efficiency, ecological function and efficient power, are explored by numerical examples. New optimal performance regions and the selection plans of optimization objective functions of the ESE system are obtained. It reveals that the characteristic of power versus efficiency behave as loop-shaped curves in spite of the heat leakage which will always decrease the efficiency of the electron engine. By properly choosing the design parameters, the ESE engine can be designed to operate at optimal conditions according to different design purpose. The preferred design area should be located between the optimal effective power condition and the optimal ecological function condition.展开更多
This paper establishes the energy selective electron （ESE） engine with double resonances as a refrigerator in one dimensional （1D） system. It consists of two infinitely large electron reservoirs with different tem...This paper establishes the energy selective electron （ESE） engine with double resonances as a refrigerator in one dimensional （1D） system. It consists of two infinitely large electron reservoirs with different temperatures and chemical potentials, and they are perfectly thermally insulated from each other and interaction only via a double ＇idealized energy filter＇ whose widths are all finite. Taking advantage of the density of state and Fermi distribution in the 1D system, the heat flux into each reservoir may then be calculated. Moreover, the coefficient of performance may be derived from the expressions for the heat flux into the hot and cold reservoirs. The performance characteristic curves are plotted by numerical analysis. The influences of the resonances widths, the energy position of resonance and the space of two resonances on performance of the ESE refrigerator are discussed. The results obtained here have theoretical significance for the understanding of thermodynamic performance of the micro-nano devices.展开更多
A double-shell model of hydroelectric-generator stator system was established. Applying the theory of mechano-electric analytical dynamics theory, the nonlinear vibration equation of magnetism and solid coupling of hy...A double-shell model of hydroelectric-generator stator system was established. Applying the theory of mechano-electric analytical dynamics theory, the nonlinear vibration equation of magnetism and solid coupling of hydroelectric-generator stator system, under steadily balanced three-phases operating condition, was obtained. According to the method of multiple scales for nonlinear oscillations, the double resonances of magnetism and solid coupling of hydroelectric-generator stater system, were investigated. It is pointed out that the system has abundant dynamics phenomenon including the attendant jumps and coexistence of multiple stable motions.展开更多
文摘提出一种全桥双谐振CLL谐振DC-DC变换器拓扑。该变换器有两个谐振网络,共用一个变压器。该谐振变换器能在全负载范围内,实现开关管的零电压导通ZVS(zero voltage switching)和副边整流二极管的零电流关断ZCS(zero current switching),变换器开关管的开关损耗低,同时消除了二极管的反向恢复损耗,实现较高效率,适用于分布式电源系统中的直直变换模块。采用基波分析FHA(fundamental harmonic approximation)方法对该谐振变换器进行分析,得到了该变换器的直流增益特性。最后,制作了一台200 W的实验样机,验证了理论分析的正确性。
基金supported by the National Natural Science Foundation of China(Grant Nos.51576207,51306206)the Hubei Provincial Natural Science Foundation of China(Grant No.2017CFB498)
文摘A theoretical model for irreversible double resonance ESE(energy selective electron) device with phonon induced bypass heat leakage which is operating as heat engine system is proposed. The thermodynamic performance is optimized and the impacts of heat leakage and structure parameters of the electron system on its performance are discussed in detail by using FTT(finite time thermodynamics). Moreover, performances of the ESE system with multiple optimization objective functions, including power output, thermal efficiency, ecological function and efficient power, are explored by numerical examples. New optimal performance regions and the selection plans of optimization objective functions of the ESE system are obtained. It reveals that the characteristic of power versus efficiency behave as loop-shaped curves in spite of the heat leakage which will always decrease the efficiency of the electron engine. By properly choosing the design parameters, the ESE engine can be designed to operate at optimal conditions according to different design purpose. The preferred design area should be located between the optimal effective power condition and the optimal ecological function condition.
基金supported by National Natural Science Foundation of China (Grant No 10765004)Science and Technology Foundation of Jiangxi Education Bureau,China
文摘This paper establishes the energy selective electron （ESE） engine with double resonances as a refrigerator in one dimensional （1D） system. It consists of two infinitely large electron reservoirs with different temperatures and chemical potentials, and they are perfectly thermally insulated from each other and interaction only via a double ＇idealized energy filter＇ whose widths are all finite. Taking advantage of the density of state and Fermi distribution in the 1D system, the heat flux into each reservoir may then be calculated. Moreover, the coefficient of performance may be derived from the expressions for the heat flux into the hot and cold reservoirs. The performance characteristic curves are plotted by numerical analysis. The influences of the resonances widths, the energy position of resonance and the space of two resonances on performance of the ESE refrigerator are discussed. The results obtained here have theoretical significance for the understanding of thermodynamic performance of the micro-nano devices.
文摘A double-shell model of hydroelectric-generator stator system was established. Applying the theory of mechano-electric analytical dynamics theory, the nonlinear vibration equation of magnetism and solid coupling of hydroelectric-generator stator system, under steadily balanced three-phases operating condition, was obtained. According to the method of multiple scales for nonlinear oscillations, the double resonances of magnetism and solid coupling of hydroelectric-generator stater system, were investigated. It is pointed out that the system has abundant dynamics phenomenon including the attendant jumps and coexistence of multiple stable motions.
