共查询到20条相似文献,搜索用时 93 毫秒
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传导性电磁干扰是开关电源的主要干扰源,国际电磁兼容测试标准规定的电源产品EMC 指标己成为开关电源的一个重要性能参数。文中从开关电源的工作原理和元器件特性出发,对开关电源的电磁干扰机理进行分析,研究抑制开关电源中传导干扰的措施。着重研究了滤波器的抑制措施,从实际应用角度对滤波器中的电感、电容等元件的特性进行了分析,给出了实用的滤波电路和元件参数。真空接触器中开关电源的电磁传导干扰抑制的应用结果表明,使用滤波器等抑制措施对电磁传导干扰有很好的抑制效果。 相似文献
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在开关电源中,高速的开关造成了严重的共模噪声干扰。介绍了一种应用于开关电源的有源共模EMI滤波器。该有源滤波器基于电流检测、电流补偿的原理,以高速运放为核心。试验证明,该有源滤波器对共模噪声的抑制能力比无源器件高20dB。 相似文献
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EMI滤波器和开关电源防护设计 总被引:8,自引:2,他引:8
本文介绍了开关电源共模、差模噪声源等效电路及电路模型;EMI滤波器的设计方法以及在实际应用中对源和负载阻抗的要求;EMC诊断的一般方法等. 相似文献
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EMI滤波器是由电感、电容等构成的无源双向多端口网络,能衰减共模和差模干扰,提高电子仪器、计算机和测控系统的抗干扰能力及可靠性.本文在研究了EMI滤波器原理基础上,提出了EMI滤波器在反激式开关电源中的设计与实现. 相似文献
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Henglin Chen Zhaoming Qian Zhaohui Zeng Wolf C. 《Electromagnetic Compatibility, IEEE Transactions on》2008,50(1):71-79
This paper analyzes the effects of parasitic inductive couplings among the filter components and printed circuit board traces in a pi-shaped common mode (CM) electromagnetic interference (EMI) filter. The result shows that some parasitic inductive couplings related with CM choke do not affect the CM EMI filter performance. And then, it proposes a high-frequency circuit model for filtration performance evaluation and prediction for pi-shaped CM EMI filter, in which the parasitic inductive coupling between input and output loops of the investigated filter is considered to be the crucial coupling parameter while other parasitic couplings are ignored. The model is simple because only one coupling parameter is involved. A procedure is introduced to extract the inductive coupling between input and output loops in pi-shaped CM EMI filter using Z parameters through virtual prototyping. Simulation and experiment finally validate the model. 相似文献
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在采用变压器耦合作为隔离电路的固体继电器中,变压器工作在自激振荡状态,通过磁芯将高频信号传递到变压器次级。这使得变压器成为对外传导发射的主要干扰源,严重时会影响到其他电子设备的正常工作。文中以某型号变压器耦合式直流固体继电器为研究对象,首先根据GJB1515A 中CE102(10kHz-10MHz 电源线传导发射要求)的规定,试验测量得到输入端电源线对外传导发射。首先,将传导发射分为差模干扰和共模干扰两种形式,并分析了传导发射的干扰源和主要传播通道。其次,在建立考虑铁心损耗和绕组铜损的变压器高频模型的基础上,利用ANSOFT Q3D 和Orcad Pspice 仿真软件得到该固体继电器用于传导发射分析的等效电路模型。仿真结果与试验结果相吻合,均表明该继电器输入端电源线对外传导发射超出国军标的要求。为抑制传导发射,文中提出在固体继电器输入端串入EMI 滤波器的优化方案。试验结果显示,优化后输入端电源线对外传导发射低于国军标的规定,提高了变压器耦合式固体继电器的电磁兼容性能。 相似文献
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Measurement of noise source impedance of off-line converters 总被引:9,自引:0,他引:9
Dongbing Zhang Chen D.Y. Nave M.J. Sable D. 《Power Electronics, IEEE Transactions on》2000,15(5):820-825
The insertion loss method is proposed to measure the noise source impedance of off-line power supplies. The information obtained through the proposed method enables the prediction of EMI filter performance and the design of a suitable filter for a switch mode power supply 相似文献
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高频开关电源EMC设计 总被引:3,自引:0,他引:3
介绍了我国和欧洲开关电源的电磁兼容标准,针对高频开关电源的工作特点,着重探讨了电磁脉冲设计、电源印制板EMC设计、EMI电源滤波器的设计和屏蔽等电磁干扰抑制方法,通过这些方法的实施,确保高频开关电源满足CISPR22 B级标准的要求. 相似文献
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开关电源纹波的产生是必然的,因此带来了EM I问题。文中介绍了互感滤波的原理,并把互感应用在全桥移相ZVZCS-PWM变换器中,理论分析了其可行性,最后仿真验证了理论分析结果。 相似文献
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Rengang Chen van Wyk J.D. Shuo Wang Odendaal W.G. 《Power Electronics, IEEE Transactions on》2005,20(3):611-619
Discrete electromagnetic interference (EMI) filters have been used for power electronics converters to attenuate switching noise and meet EMI standards for many years. Because of the unavoidable structural parasitic parameters of the discrete filter components, such as equivalent parallel capacitance (EPC) of inductors and equivalent series inductance (ESL) of capacitors, the effective frequency range of the discrete filter is normally limited. Aiming at improving high frequency performance and reducing size and profile, the integrated EMI filter structure has been proposed based on advanced integration and packaging technologies , . Some improvements have been made but further progress is limited by EPCs of the filter inductors, which is restricted by dimension, size and physical structure. In this paper, a new structural winding capacitance cancellation method for inductors is proposed. Other than trying to reduce EPCs, a conductive ground layer is embedded in the planar inductor windings and the structural capacitance between the inductor winding and this embedded layer is utilized to cancel the parasitic winding capacitance. In order to obtain the best cancellation effect, the structural winding capacitance model of the planar spiral winding structure is given and the equivalent circuit is derived. The design methodology of the layout and area of the embedded ground layer is presented. Applying this method, an improved integrated EMI filter is designed and constructed. The experimental results show that the embedded conductive layer can effectively cancel the parasitic winding capacitance, hence ideal inductor characteristics can be obtained. With the help of this embedded conductive layer, the improved EMI filter has much smaller volume and profile and much better characteristics over a wide frequency range, compared to the former integrated EMI filter and the discrete EMI filter. 相似文献