Abstract: The present invention relates to a high-temperature resistant modified silicon-containing cyanate ester resin as well as a preparation method and an application thereof. The preparation method comprises the following steps: adding a mixed solution of hydroxyl silicone oil, a silane coupling agent and an organic solvent into a mixed solution of a tetramethylammonium hydroxide aqueous solution and a polar solvent, performing hydrolytic polycondensation at a temperature of 5-40° C. for 4-8 h, and performing distillation to obtain an epoxy-containing silsesquioxane; performing pre-polymerization on the epoxy-containing silsesquioxane and a cyanate ester resin at a temperature of 50-100° C. for 1-8 h to obtain a modified cyanate ester resin; and uniformly mixing the modified cyanate ester resin and a modified anhydride, thereby obtaining the high-temperature resistant modified silicon-containing cyanate ester resin.

Abstract: A switch bootstrap charging circuit suitable for a gate drive circuit of a GaN power device includes a high-voltage MOSFET, a low-voltage MOSFET, a high-voltage MOSFET control module, and a low-voltage MOSFET control module. The low-voltage MOSFET is a PMOS transistor, and the source of the low-voltage MOSFET is connected to the power supply voltage. The drain of the high-voltage MOSFET serves as an output terminal of the switch bootstrap charging circuit. The low-voltage MOSFET control module and the high-voltage MOSFET control module generate a gate drive signal of the low-voltage MOSFET and a gate drive signal of the high-voltage MOSFET according to the gate drive signal of the lower power transistor.

Abstract: A nano-silica hybrid vinyl phenyl silicon intermediate, a preparation method therefor and a use thereof in an environmentally-friendly insulating varnish are provided. The nano-silica particles are dispersed uniformly and stably; the nana-silica hybrid vinyl phenyl silicon intermediate has the advantages of resisting high temperatures and coronas and being high in activity; the temperature index measured according to a secant method is 200° C.-240° C., the measured corona-resistant time is 18-36h, and the vinyl active sites carried thereon can have a good compatibility with polyesterimide, heat-resistant polyesters, hydrogen-containing siloxane and modified epoxy; the intermediate is particularly suitable for preparing a high-temperature-resistant and corona-resistant solvent-free insulating varnish; and there are on volatile gases during use, thereby causing on pollution to the atmospheric environment.

Abstract: A switch bootstrap charging circuit suitable for a gate drive circuit of a GaN power device includes a high-voltage MOSFET, a low-voltage MOSFET, a high-voltage MOSFET control module, and a low-voltage MOSFET control module. The low-voltage MOSFET is a PMOS transistor, and the source of the low-voltage MOSFET is connected to the power supply voltage. The drain of the high-voltage MOSFET serves as an output terminal of the switch bootstrap charging circuit. The low-voltage MOSFET control module and the high-voltage MOSFET control module generate a gate drive signal of the low-voltage MOSFET and a gate drive signal of the high-voltage MOSFET according to the gate drive signal of the lower power transistor.

Abstract: A polyoxazolidinone resin, a preparation method thereof and a use thereof in an impregnating varnish are provided. The polyoxazolidinone resin is prepared by reacting an alicyclic epoxy resin and a diisocyanate in the presence of a catalyst at 150° C. to 170° C. for 3 to 5 hours, wherein the molar ratio of the isocyanate radical in the diisocyanate to the epoxy radical in the alicyclic epoxy resin is 1:1.8 to 2.3. the impregnating varnish of the present invention uses the polyoxazolidinone resin as a bulk material in combination with acrylated epoxy resin and alicyclic epoxy resin, such that the impregnating varnish has the advantages of being heat resistant and flame retardant, low in cost, and eco-friendly, and finds use in insulation treatment of high-voltage and low-voltage electric machinery.

Abstract: A nano-silica hybrid vinyl phenyl silicon intermediate, a preparation method therefor and a use thereof in an environmentally-friendly insulating varnish are provided. The nano-silica particles are dispersed uniformly and stably; the nana-silica hybrid vinyl phenyl silicon intermediate has the advantages of resisting high temperatures and coronas and being high in activity; the temperature index measured according to a secant method is 200° C.-240° C., the measured corona-resistant time is 18-36h, and the vinyl active sites carried thereon can have a good compatibility with polyesterimide, heat-resistant polyesters, hydrogen-containing siloxane and modified epoxy; the intermediate is particularly suitable for preparing a high-temperature-resistant and corona-resistant solvent-free insulating varnish; and there are on volatile gases during use, thereby causing on pollution to the atmospheric environment.

Abstract: The present invention relates to a high-temperature resistant modified silicon-containing cyanate ester resin as well as a preparation method and an application thereof. The preparation method comprises the following steps: adding a mixed solution of hydroxyl silicone oil, a silane coupling agent and an organic solvent into a mixed solution of a tetramethylammonium hydroxide aqueous solution and a polar solvent, performing hydrolytic polycondensation at a temperature of 5-40° C. for 4-8 h, and performing distillation to obtain an epoxy-containing silsesquioxane; performing pre-polymerization on the epoxy-containing silsesquioxane and a cyanate ester resin at a temperature of 50-100° C. for 1-8 h to obtain a modified cyanate ester resin; and uniformly mixing the modified cyanate ester resin and a modified anhydride, thereby obtaining the high-temperature resistant modified silicon-containing cyanate ester resin.