Research On Micro Permanent Magnet Electrical Apparatus’s Operating Characteristics Under High-energy Electromagnetic Pulse

Permanent magnet electrical apparatuses are widely used in defense weaponsand aerospace systems, playing a control, protective, switching and other importantrole. Its performance and working reliability has a direct impact on the overallreliability of the system. Research on the operating characteristics of permanentmagnet electrical apparatus under electromagnetic pulse interference environmentis an important content to study the ability of its resistance to the complexelectromagnetic environment, and to ensure its reliable operation.Firstly, based on the micro-magnetic theory this paper chose a particular micropermanent magnet electrical apparatus as the research subject, and analyzed thepulsed magnetic field affecting on magnetic material in magnetic system.Hysteresis loop of micro permanent magnet was simulated using micro-magnetictheory. As in the polarized magnetic system permanent magnet was magnetizeduneven, combined with the permanent magnet block equivalent model, the finaloutput characteristics of the permanent magnet material in relay was determined.On this basis,3D modeling software, finite element software and flexible bodydynamics software were jointly used to establish the electromechanical couplingdynamic characteristic calculation model. Co-simulation method was used forsolving the dynamic characteristics of the relay, and the simulation results wereverified by the corresponding experiments.Secondly,3D electromagnetic field simulation software was used to simulatethe high-energy electromagnetic pulse environment, which was generated bynuclear explosion. The distribution of electromagnetic field inside theelectromagnetic pulse simulator was investigated, and the coupling form and size ofelectromagnetic pulse on electromagnetic relay was analyzed. Electromagneticpulse’s spectrum was analyzed to ascertain the concentrated frequency interval. Inthe interval, the equivalent circuit model of electromagnetic relay was founded, andtheoretical analysis and simulation methods were used to extract the parasiticparameters of electromagnetic relay. The impedance analyzer was used to test thevarious parasitic parameters to verify the correctness of theoretical extractionresults.Finally, the electromagnetic pulse interference affecting on micro permanent magnet electrical apparatus’s operating characteristics were investigated. On theone hand, circuit simulation software was used to solve the equivalent circuit, andthe interference caused by electromagnetic pulse acting on relay’s contact systemand electromagnetic system was analyzed. On the other hand, finite element methodwas used to analyze the electromagnetic pulse in the form of conduct interferenceaffecting on the relay’s operating characteristics. The study results show thatenhancing the level of electromagnetic pulse interference will cause the relay’soperating characteristics change so that the relay may occur misoperate. Theconclusions in this paper have a certain significance on enhance the anti-electromagnetic pulse interference performance of micro permanent magnetelectrical apparatus products.