Research on Modeling Method of Conducted Emission Simulation for DC Brush Motors 2020-01-1372
The conducted emission of motors has been a very important content when testing its electromagnetic interference. It has certain practical guiding significance to optimize and improve the motor in the design stage through the simulation of conducted emision circuit level. The literature research shows that in electromagnetic simulation of the DC interference motor circuit, the values of simulated and measured conducted emission are not well matched for the inaccuracy of the armature winding and commutation modeling.In this paper, an electromagnetic simulation modeling method for conducted emission of DC motor is proposed. The circuit model established in the PSPICE can simulate the actual conducted emission values of DC motor by the method. Firstly, an impedance analyzer is used to test the impedance of a certain type of window lift DC motor, and the impedance spectrum of the armature is obtained. A second-order LC circuit model is established in PSPICE and fitted to the measured armature impedance. Secondly, the commutation time is calculated by the motor parameters, and an accurate model of the motor commutation process is established in PSPICE. Finally, the time domain variation of the voltage across the 50 ohm resistor in the LISN is obtained by the voltage probe, and the voltage data is subjected to Fourier operation to obtain the conducted emission spectrum of the motor. By comparing the simulation with the test results, it can be considered that the electromagnetic simulation model established by the modeling method used in this paper can simulate the actual test results of the conducted emission of the motor, which has a good practical reference value for the motor design stage.