The Study Of The Characteirstics Of Controlled Dynamic Electromagnetic Exciting Force

Dynamic electromagnetic excitation，this non-contact way of excititation hasbeen widely applied in engineering．However, the relevant information about thecharacteristics and laws of the dynamic electromagnetic fields and dynamicelectromagnetic force is very rare．On the basis of the completed project of wavesimulate un-touched dynamic loading experiment in Nanjing Hydraulic ResearchInstitute，this article studies and explores the external characteristic of the dynamicelectromagnetic exciting force for the future research and application．In order to meet the requirements of controlled dynamic electromagneticexcitation force characteristic test，the dynamic electromagnetic excitation systemhardware and software used in the experiment carried out improvement andoptimization on the basis of the original hardware and software，and added somefeatures：①The excitation power amplifier’s current output is a difference of180°phaseof the two half-wave sinusoidal excitation current, the two-channel output inaddition to the fixed phase outside the rest of the electrical parameters can beadjusted independently；②Two current output circuit structure rests with the slip showed a parallelrelationship structure, a total of20branch.In order to solve the final stage powerdevices in each branch load imbalance problem, designed a power load equalizationcircuit for each branch to balance output current of each branch；③The efficiency of driving load is improved by changing the power amplifieroutput stage in the form；④Increase maximum output current limit protection circuit of the final outputpower transistors；⑤Changed the reverse voltage and current protection circuit of the powertransistor drive inductive load, Improve the safety of the final stage power output transistor；⑥Added frequency sweep function, Frequency stay and delay function which are notused in the original software．The study of dynamic electromagnetic force characteristics contents:①In the same case of the excitation dynamic current and the magnetic gap,dynamic electromagnetic force corresponding frequency-dependent relationshipbetween the operating frequency；②Changes in the magnetic gap relationship with dynamic electromagnetic force couplingtransfer effect；③Temperature changes affects the electromagnetic actuator generateelectromagnetic force；In the trial, dynamic electromagnetic exciting force corresponding with thechange of the excitation frequency and excitation current and the magnetic gap,obtained some results through analysis of experimental data and the experimentalcurves：①Force response to the incentive target and the electromagnetic current doesnot occur simultaneously, though there is a phase between the two of them, the peakphase of the waveform is the same；②Under the condition of the electromagnetic current and structural parametersunchanged，the dynamic electromagnetic force reduced as the frequency increases；③Under the condition of the electromagnetic current and frequencyunchanged，the coupling force by the dynamic electromagnetic force on the incentivetarget decreases regularly with the magnetic gap increases；④If the natural frequency of the incentive target is in the excitation band，resonance response occurs near the natural frequency；⑤When the resonance response occurs，there is a90°phase difference in thepeak value between the electromagnetic current and reaction force by the incentivetarget response；⑥During the process of the Electromagnetic actuator operating temperaturerising continuously，there are no differences between the electromagnetic current and the electromagnetic force in phase of the peak，but the waveform Distorted．Through this characteristic test on the controlled dynamic electromagneticforce，there is a preliminary understanding to the factors that affect the generation ofthe dynamic electromagnetic force，coupled transfer as well as the response featuresof incentive target．Laid a preliminary foundation for a better use and controldynamic electromagnetic force．...