Using Filter Capacitors and Filter Inductors to Suppress Radiated EMI
Release time:
2021-11-09
One of the most common ways to suppress electromagnetic interference (EMI) is to use filter capacitors and filter inductors. This paper will discuss the impedance characteristics and design methods of these filter components in the dual active bridge converter, and clarify the suppression of radiated EMI.
One of the most common ways to suppress electromagnetic interference (EMI) is to use filter capacitors and filter inductors. This paper will discuss the impedance characteristics and design methods of these filter components in the dual active bridge converter, and clarify the suppression of radiated EMI.
When the switch (M1) is turned on in one switching cycle, the current paths are: input voltage (VIN), inductor (L) and M1. In the meantime, the inductor current (IL) climbs and the inductor stores energy.
The principle of radiated EMI is shown, where Figure 2a on the left is the radiation principle of a dipole antenna, and Figure 2b on the right shows a general model of radiated EMI.
The energy of the antenna flows to three different parts: the first part resonates between the two poles and does not radiate into space, where jXAis the impedance corresponding to reactive power; the second part of the power is radiated into space with RrThe last part of the energy is consumed in the antenna resistance, with Rlto indicate.
General model for radiated EMI. The transformer can be transformed by the equivalent noise source (VS) and source impedance (with real RSand imaginary part XSrepresentation) for modeling.
In order to determine the radiated EMI, we need to measure the strength of the electromagnetic field generated by the transducer at a set distance. Assuming that the maximum electric field strength at the transformer distance (r) is calculated (EMAX),
Where η is the wave impedance, D represents the direction, the radius (r) is the ratio of the maximum power density in the direction (D) to the average power density of the sphere, and the electric field strength coefficient (KE) is a coefficient directly proportional to the intensity of the radiated electric field.
The impedance of the antenna and the transformer can be obtained by testing.
Related News
National unified service hotline
E-mail:Yoyo.Zhang@elec-long.com
Address: 709, 7th Floor, No.37 Baijiao South Road, Baijiao Town, Doumen District, Zhuhai City (3 # Automotive Maintenance Workshop)
Sweep to identify concerns
Customer service WeChat
Copyright©2024 Zhuhai Elong Technology Co., Ltd.
Website construction:China Enterprise Power Zhuhai SEO
Zhuhai Elong Technology Co., Ltd.
SAF Coolest v1.2 设置面板 AZFSD-ZQTE-RSSVE-ZAZ
无数据提示
Sorry, the current column has no content for the time being.!
You can view other columns or returnHome Page