| Solenoid electromagnetic system, commonly applied in high-power contactor,has serious arc erosion and big power-volume-ratio. It is responsible for convertingelectromagnetic energy into mechanical energy and is also an important part of thecontactor, whose overall performances are decided by the dynamic characteristics.The solenoid electromagnetic system studied in this paper had problems of closingbounce and breaking arc reignition, so models for fast computation of static anddynamic characteristics were built and comprehensive optimization methods for thistype of electromagnetic system were raised, which were verified by experiments.Firstly, the static characteristics of the electromagnetic system were calculatedby using the space mapping method in this paper. The detailed magnetic model ofthe axisymmetric electromagnetic system was built due to magnetic theory and theelectromagnetic force and coil flux were obtained by solving magnetic equationswith dichotomy. The finite element model of electromagnetic system wasestablished through the electromagnetic field analysis software FLUX and theelectromagnetic force and coil flux were got by simulation. On this basis, themapping coefficients were calculated and the static characteristics were achievedrapidly, which had error of at most5%with the results got by the finite elementmethod.Secondly, the dynamic characteristics of the electromagnetic system weresolved by numerical method in this paper. After an introduction to calculationprinciple and given the feature of straight moving of solenoid electromagneticsystem, the dynamic model was built. The dynamic characteristics of theelectromagnetic system were gained by using the fourth-order Runge-Kutta methodto solve dynamical differential equations. The coil current and displacement ofmoving contact were compared with the measured results, whose accuracy wasverified.Then, the dynamic characteristics were regulated and optimized in the aspectsof structure parameters and coil voltage of electromagnetic system. Aimed at theproblems existed in the experiments, the dynamic characteristics were analyzed indetail and therefore the corresponding improved methods were pointed out. Thestructure parameters of the electromagnetic system were adjusted according tooptimization measures, whose effectiveness was demonstrated by the simulation.Based on the adjustment of the structure parameters, a new control strategy for thesupply voltage of coil was raised for the control, reduced the moving contact closing speed about60%and inhibited its closing bounce.Finally, the coil control circuit was designed and the experiment was made toprove the optimization. The general requirements of the control circuit werepresented according to the control strategy, and thus the hardware design andsoftware program were finished and reached the intended target by debugging. Theonly make and life test with rated load were carried out. The results showed that themaking capacity and electrical life were improved significantly for optimizedelectromagnetic system and that the optimization method was effective.The thought and method of this study can also be applied to the design andoptimization of other kinds of electromagnetic system. |
PDF Full Text Request