中文摘要：

针对汽车用电设备对供电电源的高要求，设计了一种24 V转5 V低纹波大功率供电系统。该系统采用集中式供电，可直接供多个车载设备同时工作。提出了以LM 5005芯片为核心的降压电路设计方法，分析了各主要器件的特性，推导了部分器件的计算方法，针对功率、纹波、抗干扰等关键指标对主要电路参数进行了设计分析，并进行了多组测试。测试结果表明，该电源系统可提供平均15 W的负载功率，并且纹波控制在100 mV以下，能够满足目前大部分车载设备的供电要求，且运行稳定，噪声较低，具有较好的可维护性。该电源系统解决了传统车载设备供电方式中存在的独立降压模块多、输出电源纹波较大、电源转换效率不高、多干扰源未分类处理等问题。

英文摘要：

In consideration of vehicle‐mounted equipments for the power supply system ,a high‐power and low‐ripple power supply system with 24‐volt changing to 5‐volt is designed in this paper .It adopted centralized power supply which can provide power to several modules directly .A reduced voltage circuit which takes LM 5005 chip as the core module was proposed .The characteristics of main parts of the circuit were analyzed .According to the key indexes of power ,ripple wave and anti‐jamming ,the main circuit parameters were designed .Besides ,multiple groups of tests were done .The results show that the power system can provide 15W load power on the average , and ripple wave is controlled below 100 mV ,which can meet power supply requirement of most vehicle‐mounted devices .And the power system operates stably ,with low noise .Besides ,it has good maintainability .The power system solves the problems of traditional power supply mode of vehicle‐mounted equipment ,such as too many independent voltage modules ,large ripple w ave of output pow er ,low pow er supply conversion efficiency and non‐classification treatment of multiple interferences .