Analysis And Expeirment Research On The Electromagnetic Compatibility Of Truck Crane

The development of national infrastructure promotes the process of intelligenceand large-scale in construction machinery, and promotes the application of intelligentcontrol technology and intelligent components. For the market demand of safety andgreen environmental protection, electromagnetic compatibility (EMC) has become thebottleneck restricting the development of the industry.The product characteristics and work environment of construction machinery aremore likely to cause EMC failure: The following characteristics of constructionmachinery application forms a strong electromagnetic disturbance sources whichcannot avoid: cluster construction of large power equipment, adjacent to thehigh-voltage lines and communication base station. Because the steel body arm shelfstructure are tens of meters or even hundreds of meters in length, the coupling ofelectromagnetic interference on wire harness and component which is inside is fargreater than the direct harassment; The lower functional safety design level of theintelligent control system causes malfunction of the system in bad environment.In order to design the immunity to electromagnetic, we must masterelectromagnetic disturbance source, coupling path, harassment first.communicationcomponent sensitivity.We can’t use conventional experimental environment and testmethods (such as: car) because of complex electromagnetic disturbance source andthe huge weight and volume, Related core technology of the foreign enterprise issecret, industry EMC research is blank in china, We haven’t mastered the independentcore technology of test and analysis of the construction has not yetWe has not yetmastered independent core technology of equivalent test and analysis of complexelectromagnetic environment in construction and transmission and the EMI designand manufacturing of the whole/part. The EMC problem can only be improved inuse, long cycle, high cost, high risk, the product is difficult to meet the demand of the market.Research of this paper from the basic EMC, taking truck crane as the researchobject, research the construction machinery EMC technology: Test and analysis thecharacteristics and the level of electromagnetic disturbance source of truck crane ontypical conditions, establish the truck crane EMC simulation model, realizingsimulation analysis and prediction of the machinery EMC, master the method of EMCtest,analysis, simulation for construction machinery, which has been appliedsuccessfully in construction machinery product analysis, test, design:According to the structure of truck crane electrical system, starting from theproduct circuit principle and characteristics of truck crane, to research " test, analysis,simulation " of electromagnetic compatibility.（1） Disturbance source interference wave testElectronic control system of automobile crane comprises a power rectifiermodule, high current switching devices and high-power load, combined with theelectromagnetic disturbance general caused by current/voltage mutation,electromagnetic alternating, we can determine three possible electromagneticdisturbance sources of the truck crane control system: power supply system, thecontact action, transient load of. According to the source distribution, harassment inelectronic control system of truck crane electrical connection and harassment oftransmission determine the generator as the key test etc; And under typical conditionsof the truck crane, adopting low distortion test method, test and obtain theelectromagnetic disturbance waveform, transmission impedance and the free fieldelectromagnetic background noise;a large sample test is used, in order to eliminate the effects of various random error.Based on the problem of test data and analysis results in a large amount of data,difficult to management, establish electromagnetic compatibility database, the contentrelates to the typical sources of electromagnetic interference mechanism, test, testprocess, the reference standard, test data, playback, interference characteristicparameters, extend store the test data and the electromagnetic characteristics of theinterference source data, the propagation characteristics of cable coupling characteristic data and typical components in laboratory conditions.（2） Analysis of characteristics of the interference sourceBecause of the random test data and test error, can not be directly used foranalysis of electromagnetic compatibility, there is the need for data filtering, featureextraction and post processing. Through the analysis of the data, obtaining thecharacteristic parameters of typical interference source, the process is: to analyze thecharacteristics of electromagnetic noise background, application of wavelet transformtechnology will separate target jamming source waveform data and noise; using thestatistical theory of electromagnetism, getting parameters distribution of harassmentthrough the analysis of parameter estimation, hypothesis testing and regression. Therandom characteristics of electromagnetic interference source parameters areeliminated, Build characteristic parameter statistical model, analysis and obtain theeigenvalue of typical interference peak, rise time, fall time, duration, pulse width.（3） The product EMC SimulationAiming at the truck crane electromagnetic compatibility analysis and forecastdemand, analyzing the interference source mechanism further, combining with themeasured data, adopt the concentrated parameter contains the model parameters ofsources of interference simulation modeling technology, a typical interference sourcesimulation model based on equivalent circuit method, including the engine, relay,electromagnetic valve and harness model; establish the simulation model of multifactors coupling interference source characteristics including structure characteristics,automobile wiring harness and cable crane position feature, from the interferencesources, transmission/coupling path and sensitive equipment three aspects to revealthe electromagnetic compatibility characteristics of construction machinery further.Through the above research, to fully grasp the three key technologies of study ontruck crane electromagnetic compatibility: testing technology, analysis technologyand simulation technology, providing technical support for construction machineryelectromagnetic compatibility research which is representative by truck crane; Theresearch results achieved to provide theoretical basis and data support forelectromagnetic interference suppression and electromagnetic compatibilityrectification of electronic control system of TRUCK crane, which promote theformulation and implementation of industry standards of EMC design (limit of interference and noise immunity) and test standards.