星用基于UC1845多路输出双管反激开关电源设计

摘要

In order to solve the problem of the switch voltage stress and multi-channel output stability of the spacecraft DC/DC converters when the high voltage input and multi-channel output occur,a sort of multi-channel output dual switch flyback power supply based on UC1845 was designed. The dual switch flyback converter is adopted in main circuitas to make the voltage stress of each main switch just input voltage to meet the high reliability application requirement of spacecraft. Additionally,the magnetically-isolated feedback voltage stabilization control is used in the circuit to control the multi-channel output. The low dropout three terminal voltage stabilizer is employed at the output end. The output load stability degree of each channel is better than ± 1%. The current-controller UC1845 is adopted in control circuit. It has advantages of high voltage regulation rate,high load regulation rate,fast transient response. The experimental result shows that the power supply is safe,reliable,has high sta-bility,small ripple,high efficiency,and meets the design requirements.%为了解决航天器DC/DC变换器高压输入多路输出时，开关管电压应力以及多路输出稳定度问题，设计了一种基于UC1845的多路输出双管反激开关电源。主电路采用双管反激式变换器，使主开关管上的电压应力仅为输入电压Vin，满足航天器高可靠性的应用需求；同时电路采用磁隔离反馈稳压控制，通过一个反馈控制量实现多路输出，输出端配合应用低压差三端稳压器，各路输出负载稳定度优于±1％。控制电路采用电流型控制器UC1845，其具有电压调整率高、负载调整率高和瞬态响应快等优点。实验结果表明，该电源安全可靠、稳定性好、纹波小、效率高，达到了设计要求。