离子推力器高效高可靠性屏栅电源设计

Design of High Efficiency and High Reliability Screen Supply for Ion Thruster

为了进一步提高离子推力器的可靠性和使用寿命,采用6个电源模块串联输出的方法设计了高效高可靠性的屏栅电源试验样机,每个模块采用全桥LLC谐振变换器,并对屏栅电源模块的性能、打火时开关管的瞬态电流应力分别进行了测试研究。结果表明:屏栅电源模块采用全桥LLC谐振变换器,可以实现零电压开通零电流关断,整个电源的转换效率提高到96.9%;单个电源模块输出电压为210V,电源模块内部没有>250V的交流电压峰值,简化了高压绝缘设计的难度;变换器初级较大谐振电感的限流作用使得推力器出现打火时,开关器件瞬态电流仅为40A。该设计能有效提高屏栅电源的效率和可靠性,可以应用于小行星探测等深空探测航天器的电推进系统。

In order to further improve the reliability and service life of the ion thruster,a screen supply test prototype with high efficiency and reliability was designed by using six power modules in series.Each module adopted full bridge LLC resonant converter.And the transient current stress of the switch as well as the performance of the screen supply module were tested when the thruster was ignited.The results show that the screen supply module can be turned on and off with zero voltage and zero current by using full bridge LLC resonant converter,and the conversion efficiency of the whole power supply can be increased to 96.9%.While the output voltage of a single power supply module is 210 V,the peak value of AC voltage is not more than 250 V in the internal power supply module.This can simplify the difficulty of high-voltage insulation design.In addition,owing to the current limiting action of the larger primary resonant inductance,the transient current of the switch is only 40 A when the thruster is ignited.This design can effectively improve the efficiency and reliability of screen supply,and can be applied to the electric propulsion system of deep space exploration spacecraft such as asteroid exploration.