The Design Optimization Of Intrinsically Safe Electromagnets

In mechanized mining era the development and application of new technology is required, and also developing hydraulic supports of high performance and high reliability. New hydraulic supports generally have solenoid-driven electro-hydraulic control valves. The use of electro-hydraulic control valves increases the level of automatic control of hydraulic supports.A Electro-hydraulic control valve consists of one solenoid pilot valve and one main hydraulic control valve. Hydraulic support according to different functions will been equipped with different number of electro-hydraulic control valves to control the activities of hydraulic support cylinder, and so the hydraulic support achieve the lifting, pushing the slide, shifting planes and other activities. Most of the valves currently used in Coal is dependent on imports, the disadvantage of which lies in maintenance costs, long supply and maintenance period. Therefore designing and manufacturing reliable national products is imperative.In recent years, research methods of the intrinsically safe electromagnet are focused on numerical analysis and finite element analysis, and simulation of static magnetic field. Few studies concerned about transient magnetic field and temperature field simulation.Based on the analysis of the traditional electromagnetic design method, the finite element simulation and optimization method should be integrated to achieve optimum design of intrinsically safe electromagnets, which will greatly speed up the pace of domestic the electro-hydraulic control system.Firstly, one solenoid was achieved by preliminary theoretical calculations, re-calculation, optimization and finite element simulation, so some empirical parameters were adjusted according to the simulation data to obtain the final design equations of the electromagnet. The performance of the electromagnet has been verified by experiment of the final product. During optimization of the solenoid, The sequential quadratic programming method has been employed to solve the nonlinear optimization problem, and assign minimum power dissipation and minimum volume as the objective functions, and temperature, rise and force as constraints to solve optimization problem.Using Ansoft maxwell2D/3D electromagnetic finite element analysis software, static magnet simulation, dynamic simulation and temperature field simulation were carried out, and got the static suction curves of the electromagnet the dynamic force curves, the displacement curves, coil current and armature velocity curves. Temperature field simulation results are coil temperature distribution. After the above analysis, it has been necessary to analysis dimensions sensitivity to get key dimensions' affection on performance. Simulate the whole electro-hydraulic system by Using AMESim software, to verify that the performance of electromagnet met the requirements.The DC solenoid electromagnet's magnetic circuit structure is complex, and furthermore theoretical calculation does not take into account the nonlinear and eddy current loss in core magnets, which makes it difficult to get accurate results just relying on the theoretical calculation of the performance parameters, and the electromagnet materials actual state plus processing error will also make the product performance different from the theoretical value. To assess the accuracy of the design, the subject of using displacement, force, speed sensors and NI data acquisition system was taken as the experiment method. The experiment data verify the accuracy of electromagnetic design, while the values of the magnetic attraction force have slightly deviation with the original design because of processing errors.This topic has not only got optimization results of the electromagnet, but also optimize the design method itself, and the conclusions also apply to other low-power solenoid electromagnet.