Parametric Simulation And Experimental Analysis Of The Linear Variable Differential Transformer Used In Proportional Valve

With the rapid development of hydraulic industrial, electro-hydraulic proportional technology has made a great progress, at the same time, the performance requirements of sensor used in proportional valve is higher and higher. The research of high performance sensor used in proportional valve is very important.Using the linear variable differential transformer(LVDT) of the proportional valve as the research object, according to the requirements of the proportional valve for the LVDT static characteristics, use the electrical and structural parameters which impacting the LVDT static characteristics to do theory, simulation and experimental analysis, optimizing an LVDT static characteristics. Using the distribution theory of transformer main magnetic flux and leakage magnetic flux as the foundation, through the Ampere circuital theorem to analyse the electromagnetic field of LVDT, thus derive the mutual inductance of the primary coil to the secondary coil; through the analysis of equivalent circuit, derived the output of a single secondary coil and the differential output of secondary coil. And based on the differential output characteristic of LVDT to analyze the relationship between its static characteristics such as sensitivity, zero residual voltage with the electrical and structural parameters.According to theoretical knowledge of electro-magnetic field, combined with finite element analysis software Ansoft Maxwell used in the electromagnetic field, to simulation analysis for the LVDT, detailing the basic steps of3D electromagnetic simulation analysis such as specified type of solver, create a geometric model and specify the material properties, boundary conditions and excitation source, meshing and setting up the solving options, validation, model and solving and post-processing.Using the LVDT of the proportional valve as the research object, apply the three-dimensional mapping software SOLIDWORKS to establish the LVDT three-dimensional solid model. Apply magnetic field finite element method to the LVDT simulation study, calculated the output voltage of the secondary windings of the LVDT.Take advantage of the building model, separately change the electrical parameters such as excitation amplitude, excitation frequency, and structural parameters such as coil diameter, coil axial length, core length of the LVDT, simulated analysis the different models to explore the impact tend of the LVDT static characteristics by electrical, structural parameters.The comparative analysis between the LVDT simulation results with the experimental results indicated, in the allowable range of error, the simulation results are consistent with the experimental results. The simulation results show that the modeling and simulation steps of LVDT are correct, the simulation results can reflect static characteristics such as the sensitivity of LVDT. This article research results have important guiding significance to the optimization design of the LVDT and its applicable proportional valve.