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Sheet Molding Compound (SMC) materials are extensively utilized as high-voltage insulation materials in electrical equipment. SMC materials are prone to aging after long-term operation. Conducting non-destructive testing to assess their electrical and physicochemical properties is crucial for the safe operation of electrical equipment. This study identifies the optimal equipment parameters for testing SMC materials using Laser-Induced Breakdown Spectroscopy (LIBS) technology through experimental investigation and also explores the ablation characteristics of SMC under various laser parameters. The results indicate a significant positive correlation between the ablation depth and laser pulse number, while there is no correlation with single laser pulse energy. However, the ablation area demonstrates a strong positive correlation with both single laser pulse energy and laser pulse number. Additionally, LIBS spectral analysis provides elemental results comparable to Energy Dispersive Spectroscopy (EDS), facilitating the examination of variations in Na, Ti, Fe, Mg, Ca, and C elemental contents with depth. Moreover, an enhanced iterative Boltzmann plot method is suggested for calculating the plasma temperature using 21 Fe I spectral lines and the electron density using the Fe II 422.608 nm line. The variations of these plasma parameters with laser pulse number are documented, and the results show consistent trends, confirming that the laser-induced SMC plasma adheres to local thermodynamic equilibrium. [ABSTRACT FROM AUTHOR]

For the influence of the parasitic parameters of MOSFET on the performance of LLC resonant circuit, the equivalent analysis of the parasitic capacitance of MOSFET is first carried out. Based on this equivalent model, in the LLC resonant conversion circuit, due to the existence of parasitic parameters, the impact of each stage of the circuit is analyzed. Then, the nonlinear characteristics caused by parasitic parameters are modeled based on the Angelov model, and the impact of the model on the DC circuit is analyzed. Finally, the LLC resonant circuit model is established under MATLAB, and the influence of parasitic parameters is considered in the simulation model. The simulation results show that the equivalent model established in this article can better reflect the operating characteristics of the MOSFET device; at the same time, due to the presence of parasitic parameters, the output gain and resonance frequency of the LLC resonant circuit will be affected, especially the resonance frequency Greater impact.