A method for suppressing electromagnetic interference of a controller of a vehicle motor

Abstract

The invention relates to the field of vehicle electrical motors, in particular to an electromagnetic interference suppression method for a controller of a vehicle electrical motor. The electromagnetic interference suppression method comprises the following steps: embedding magnetic resistance materials in a notch of the vehicle electrical motor so that the vehicle electrical motor is at a flux weakening state; increasing a decoupling capacitor between the power supply of each integrated circuit of a controller and the ground, and bridging an electrolytic capacitor at the input end of the power supply; applying a soft-switching technology so as to carry out the status switching of a switching element during zero voltage and zero current of a switch; correcting the current waveform of the power supply so as to reduce the content of current harmonics and reduce the external electromagnetic interference of the power supply. The magnetic resistance materials are fixed in the notch of the vehicle electrical motor, and through the PCB (Printed Circuit Board) wiring design and the controller design, the electromagnetic interference of the controller of the vehicle electrical motor is effectively inhibited.

Description

technical field [0001] The invention relates to the field of vehicle motors, in particular to a method for suppressing electromagnetic interference of a controller of a vehicle motor. Background technique [0002] In the operation of existing vehicles, EMC (Electro Magnetic Compatibility, Electromagnetic Compatibility, Electromagnetic Compatibility) has seriously exceeded the standard phenomenon. Many vehicle manufacturers, due to their small scale, limited production capacity, serious lack of technology development and technical reserves, have no concept of EMC , put EMC, which has a serious impact on people's health, into the back of our minds. Once there is a test need, we usually use cable coating, adding magnetic beads, magnetic rings, etc. to deal with it temporarily. At the same time, this method is expensive and difficult for ordinary workers to operate. And not easy to grasp. [0003] The electromagnetic interference sources of the BLDC (Brushless Direct Current Mo...

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Problems solved by technology

[0004] In the prior art, PWM control is commonly used for brushless DC motors: the PWM frequency is used to control the switching frequency of the three-phase bridge, and the duty cycle is used to control the effective current flowing through the motor windings to control the motor speed. After testing, the PWM switching frequency is 20KHz, The frequency range of the interference signal is concentrated in 0.15KHz-5MHz, and there is just the PWM operating frequency in this range. At the same time, the motor design of the existing PWM brushless DC motor is in a state of rich magnetism. When the motor is designed, the oversaturated magnet The road will generate large electromagnetic interference

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