Design of Vacuum Interrupters for Variable Frequency AC Aviation Applications
With the growth of aviation electrical loads,traditional constant voltage and constant fre-quency power supplies are no longer able to meet the requirements of modern aircraft electrical systems,and variable frequency power supplies emerge as the new development direction.However,the variable frequency vacuum interrupter technology faces three challenges:the increasing breaking difficulty,the de-creasing current-carrying capacity,and the design limitations of small volume and lightweight.Through two key technologies:improving the breaking capacity in a small space and optimizing the current-carrying capacity with a lightweight structure,a variable frequency vacuum interrupter design scheme suitable for aviation variable frequency condition is proposed.The contact factors affecting the current breaking ability under variable frequency conditions are analyzed,and a small volume contact structure for the vacuum in-terrupter is designed.An integrated external main shielding cover structure is proposed to increase the contact diameter and provide assurance for improving the breaking capacity.A lightweight method for con-ductor structure under skin effect is proposed,an external shielding cover is used to increase heat dissipa-tion capacity,and an aviation variable frequency AC vacuum interrupter is developed.Based on a designed three-phase contactor prototype,an experimental environment suitable for aviation variable frequency con-ditions is established,and the breaking capacity,insulation performance,and temperature rise of the inter-rupter are experimentally studied.The results show that the designed vacuum interrupter can effectively break the overload current of 1.68 kA in the frequency range of 360 Hz～800 Hz,and the prototype suc-cessfully breaks the three-phase overload current of 1.1 kA 50 times.The contact voltage drop of the three-phase main circuit remains stable before and after interruption,with a maximum value of only 83.49 mV,which is much lower than the design value of 100 mV.The overall weight of the whole prototype is only 975 g,which meets the design requirements and has higher breaking capacity.The research provides experimental data support for the development of aviation variable frequency power supply systems and is of great signif-icance for promoting the application of vacuum interrupter technology in aviation electrical field.
Variable frequency aviation power supplyVacuum interrupterAviation AC contactorMedium-frequency breaking characteristics
万方数据
维普
