An investigation of maximum EMI path inside the hybrid electric vehicle

摘要

Impelled by the pressure of environment protection and energy crisis, new energy automobiles, especially the hybrid electric vehicle (HEV), have been rapidly developed. However, inside the HEV, the high-power devices, such as DC power convertor and motor drive controller, include switch components. The turn-on and turn-off behaviours of these switch components will bring about peak voltage and oscillating current signals, causing serious electromagnetic interference (EMI) in a wide frequency range. Therefore, this paper studies the conducted EMI in these two systems of HEV, measures the spectrum of conducted noise current on the main cables, respectively, under starting speed and idle speed. And the comparison of noise features between different cables shows that the large current on DC-AC power lines is largest noise source when motor starts, and the peak signals produced by the switch behaviours of MOSFET is the most serious noise source under the idle speed.