电动汽车DC/DC变换器电磁干扰优化研究

电动汽车DC/DC变换器是车内低压电器的供电源,实现高功率密度、高效率的高低压转换的同时产生了严重的电磁干扰问题。分析了DC/DC变换器的工作原理以及EMI的主要来源,并基于ZVS移相全桥DC/DC变换器提供了结合软开关技术、EMI滤波以及减小系统分布参数的优化措施。实验表明,优化后DC/DC变换器达到了GBT18655标准的基本要求,电动汽车的电磁环境得到大幅改善。

Single Photon Scattering in a Pair of Waveguides Coupled by a Whispering-Gallery Resonator Interacting with a Semiconductor Quantum Dot

The single photon scattering properties in a pair of waveguides coupled by a whispering-gallery resonator in- teracting with a semiconductor quantum dot are investigated theoretically. The two waveguides support four possible ports for an incident single photon. The quantum dot is considered a V-type system. The incident direction-dependent single photon scattering properties are studied and equal-output probability from the four ports for a single photon incident is discussed. The influences of backscattering between the two modes of the whispering-gallery resonator for incident direction-dependent single photon scattering properties are also pre- sented.

Single Photon Scattering Properties in Coupled-Resonator Waveguide Coupling with a Nanocavity Interacting with an External Mirror

We investigate theoretically single photon transport properties in coupled-resonator waveguide coupling with a nanocavity interacting with an external mirror. By using the discrete coordinates approach, transmission and reflection amplitudes of the propagating single photon in the waveguide are obtained. The influence of the coupling strength between the nanocavity and the external mirror on the single photon scattering spectra is discussed. We also extend the results to the waveguide with linear and quadratic form dispersion relations.

ZVS全桥倍流同步整流拓扑的研究

目前全桥电路的研究大都集中在移相全桥领域,但移相控制存在副边同步整流管难以实现软开关的问题,导致增大了副边的整流损耗。此文介绍了一种全桥倍流同步整流器,即可实现全桥开关管的ZVS,又改善了次级同步整流软开关不足问题,并通过倍流改善了电流纹波。最后对变换器进行了实验,验证了理论分析。