星载开关电源的电磁干扰抑制技术

电磁干扰（EMI）抑制技术是保证航天器各功能单元正常运行互不干扰的重要技术。开关电源是航天器内电磁干扰的主要来源。基于对星载开关电源DC/DC和负载点电源POL电磁干扰特性的测试结果，提出了一种星载二次电源系统的电磁干扰抑制方案，采用高稳晶振+控制器+时钟管理芯片硬件与软件设计结合的方法，利用高稳晶振为电源模块提供稳定时钟，通过控制器实现时钟管理芯片的分频和时钟分配。系统以非同步方式上电，软件控制时钟管理芯片输出电源模块同步时钟，然后软件打开时钟同步的使能，实现星载开关电源（DC/DC和POL）开关频率的外同步，最后通过测量输出电压频谱的方法验证了电磁干扰抑制方案的有效性。

Electromagnetic Interference Suppression Technology for Switching Converters of Onboard Secondary Power Supply

Electromagnetic Interference (EMI) suppression technology is an important technology to ensure that all spacecraft functional units can work normally together. The EMI in spacecraft comes mostly from the switching converters, DC/DC and the point-of-load POL. Ground tests for the EMI characteristics of the onboard switching converters are conducted. Based on the test results, an electromagnetic interference suppression design for the onboard power supply system is proposed, in which the hardware consists a highly stable crystal oscillator, a controller, a clock programmable buffer and some clock drivers, to provide a highly stable external synchronization clock for the switching converters. Meanwhile, the software design to realize a stable clock and power-on sequence control are introduced. All DC/DC and POL are working in the synchronization mode, in which the switching clocks are from external clock drivers. Finally, the feasibility and effectiveness of the EMI suppression design is verified by the method of measuring the output voltage spectrum.