A Common Mode Current Suppressor for Electric Vehicles Based on Electromagnetic Loss

Abstract

The invention discloses an electromagnetic loss-based electric vehicle common mode current suppressor. The suppressor circuit adopts a ladder-shaped network form of a lumped element, and the unit structure is a low-pass circuit composed of a series inductance coil and a parallel capacitor. In view of common mode current at the frequency range of 1 to 30MHz conducted along a cable-chassis in the electric vehicle, in consideration of the length Pu of the unit structure being far smaller than the wavelength of the common mode current and convenience of circuit preparation, Pu is approximately equal to 2cm, the inductance coil is filled with composite magnetic material with the solid part and the imaginary part of magnetic permeability to be 10 magnitude, and the capacitor is filled with composite dielectric material with the solid part and the imaginary part of the dielectric constant to be 10 magnitude. The common mode current suppressor is serially connected onto the cable of the electric vehicle, and as the suppressor has a large attenuation coefficient, the common mode current is rapidly attenuated exponentially, and the common mode current in the subsequent circuit can be strongly suppressed. The suppressor of the invention is simple in structure, convenient to prepare, and can selectively and high-efficiently suppress common mode current at a wide frequency band range.

Description

technical field [0001] The invention relates to the field of electromagnetic compatibility, in particular to suppressing the common-mode current in a wide frequency range on electric vehicle cables. Background technique [0002] The high-power power converters of electric vehicles will generate broadband electromagnetic noise and electromagnetic interference during their work. They mainly propagate along the cables and chassis in the form of common-mode currents, affecting the normal operation of the electrical equipment and control systems on the vehicle and causing serious damage. The problem of electromagnetic compatibility is not conducive to the reliable operation and industrialization process of electric vehicles. [0003] The common mode current is generated by the interaction between dU / dt and parasitic capacitance, and its conduction loop is: phase line, parasitic capacitance to ground, and earth. Correspondingly, suppression of common-mode current should be consid...

AI Technical Summary

Problems solved by technology

Grounding can suppress the common-mode current, but the common-mode current is often high frequency. Even if one point is grounded, it will still be the effect of multi-point grounding due to the existence of distributed capacitance, forming multiple ground loops is not conducive to the common-mode current. inhibition

Series common-mode inductors are often aimed at a certain frequency point, which is not easy to suppress common-mode currents with a wide frequency band, and may even cause larger common-mode currents at other frequency points

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