Brushless DC Motor Interference Analysis Of Magnetic Measurements And Compensation Technology Research

Measurement and study of the geomagnetic field have great significance to aerospace,resource exploration, transportation, telecommunications, national defense construction,earthquake prediction, space weather, and environmental monitoring. Generally use theaeromagnetic method to get the regional geomagnetic field value. But in aeromagneticprocess, the leakage magnetic field of the brushless DC motor used on aircraft in theenvironment obvious interfere the geomagnetic field measurements. In order to solve theproblem of electrical leakage magnetic field interference, this paper have researched onmotor leakage magnetic field of spatial and temporal distribution characteristics, thendesigned effective shielding and compensation package.Firstly, starting from the structure and working principle of the brushless DC motor,designed brushless DC motor model in professional low-frequency electromagnetic fieldsimulation software Ansoft Maxwell, and calculated and simulated brushless DC motor’smagnetic field in the environment.Then a series of leakage magnetic field measurement in the static and dynamicexperiment for motor was designed, and the correctness of the calculation model of themotor was verified; In the motor static cases, gained the change rule of leakage magneticfield for the motor with space distance, rotor position and environment magnetic field. inthe dynamic circumstances, the relationship of the motor leakage magnetic field betweenthe space distance and the motor speed was found.Finally, on the basis of computational simulation and experimental studies, the designgives three solutions to solve motor magnetic leakage field interference, include magneticshielding, static compensation, dynamic compensation. By means of the simulationcompared the shielding effect of magnetic shielding materials on motor magnetic leakagefield. The relationship of hard iron bias caused by the rotor and the rotor position have beenanalysis, designed soft iron compensation model, experiments showed that thecompensation of soft iron have reduced to20nT. In the dynamic case, the design frequencyinterference filters proved by calculating the effectiveness of the filter.This article presented a systematic method for studying engineering electromagneticfield, then did system analysis on motor leakage magnetic field interference tomeasurements of the geomagnetic, designed magnetic shielding and compensationalgorithms to solve the motor leakage magnetic field interference.