The Electromagnetic Radiation Simulation Study Of Automobile Air Conditioning System Based On MoM

Electromagnetic interference generated by the automotive air conditioning directEnter inside the Radio equipment and electronic equipment by car wire,Or throughthe antenna (such as Ignition Department of high-voltage lines,a longer cable and chippin in equipment) Enter inside the radio equipment.These disturbances will becoupled to the antenna core line,radiation from the antenna (such as receiving thebroadcastantenna), resulting in the radiation interference; Thus, study the problem ofelectromagnetic compatibility of automotive air-conditioning, a direct impact onvehicle electromagnetic compatibility, have a significant research value; But thepresent situation, at home and abroad to do research and study in EMC analysis of theautomotive air conditioning systems is still very rare.The method of moments is a kind of operator equation which is transformed intoa matrix of discrete equations. Because it can calculate the spatial objects of arbitraryshapes in the surrounding lectromagnetic field distribution, in a other word it can beapplied to any boundary conditions, so it has been widely used. This paper studies themethod of moments for the mathematical theory,and the method commonly used inmatrix. Studied the aid of the method of moments for automotive air conditioningsystem and the problem of electromagnetic interference.This paper describes in detail the mathematical principle of themethod ofmoments, and describes the routine for solving matrix, and Krylov subspace iterationmethod; Elaborated on the method of moments based on the weighted residualmethod.It introduces the main components of automotive air conditioning system, andfind the main source of electromagnetic interference,and analysis respectively themechanism of electromagnetic interference of the main interference source (airconditioner power switch, controller); At the same time, elaborated the workingprinciple of the cooling fan motor, and has carried on the detailed analysis ofelectromagnetic interference. Based on the moment of method, establishment of mathematical model forpermanent magnet brushless DC motor, select the sine value basis function as currentdistribution function using Helen-equation,and according to the integral equationrelation of the electromagnetic field distribution and current distribution, then get themotor electromagnetic field distribution. Using Matlab carry the electromagneticradiation simulation, get the motor electromagnetic field simulation image; And thenget the conclusion: the electromagnetic distribution trend on motor rotor is, alongwith the increasing distance from the center of the rotor, the electromagnetic fieldincreases ceaselessly, but as with the is, along with the increasing distance from thecenter of the rotor, the electromagnetic field increases ceaselessly, but as with therotor center distance reaches a certain value, the electromagnetic field strengthstrength with the distance increase and decrease.Strictly abide by the "TL965(2006-11) of adjacent interference eliminatingdevice technical requirements", test electromagnetic radiation of the automotive airconditioning cooling fan motor, and has been using suppression measures before thecooling fan motor electromagnetic radiation image. The image shows, the restrainingmeasures before the fan motor electromagnetic compatibility has not reach thestandards; from the analysis, put forward the corresponding suppression measures,test the fan motor electromagnetic radiation again; Contrast using suppressionmeasures before and after the motor electromagnetic radiation image, can know themotor electromagnetic interference performance achieved significant improvement,and through the standard provisions. Thus, the anti interference measures are feasibleand effective.Therefore, based on the method of moments for automotive air conditioningsystem and electromagnetic radiation is effective, and it has a certain instructionsignificance.