【作者】 方丰勤；

【导师】 王晓远；

【作者基本信息】 天津大学 ， 电气工程， 2007， 硕士

【摘要】 本文介绍了DMA-48V/75A开关电源模块的结构、原理及设计过程等。本文设计的DMA-48V/75A开关电源模块由输入级电路、单相功率因数校正PFC电路、全桥软开关DC-DC变换电路、输出滤波电路、无主从自动均流电路、单端反激型辅助电源电路等部分组成。本文通过对单相功率因数校正PFC电路原理的阐述,提出了一种实用控制器的参数选择方法;并根据工程实际经验,对电路进行了简化;由于采用了低损耗的无源吸收电路,开关管的关断损耗得以大大降低。本文通过对全桥DC-DC变换器的控制策略的分类,提出了一种新型的控制方法—“相位延迟控制”。利用在变压器的副边上加入一个简单LCD辅助电路,实现了滞后臂的零电流开通和关断。本文设计的DMA-48V/75A开关电源模块具有多种保护措施,如过压、过流、过温、输出欠压等,使得系统的可靠性得到提高。根据本文设计的DMA-48V/75A开关电源模块所组成的通信电源系统,各模块之间负载电流可通过无主从方式自动均流,所有模块均可以带电插拔,从而可以方便地实现系统扩容,增加了系统的冗余度。由于模块工作在高频开关状态,模块具有体积小、重量轻、可靠性高等一系列优点。更多还原

【Abstract】 This paper presents the structure, the principle and the design of DMA-48V/75A switching mode communication power system. The system consists of the AC input stage, single phase PFC, main inverter, output low-pass filter, auxiliary power supply, and load current sharing circuit, etc.The operation principle and practical design method of the PFC stage is introduced. This method is based on the theoritical analysis, but it’s simplied according to the application. The system is both stable and reliable. A low power loss passive snubber is added to the Boost converter, therefore the switching losses are reduced.By the classification of the typical control method,”phase overlapped control”(POC)is proposed. Low cost, high reliability are its advantages. ZCS of the lagging leg is realized by adding a simple LCD circuit to the transformer’s secondary side.System exceptions, such as over-voltage, over-current, over-temprature, DC under-voltage, etc, are dealt with by carefully disigned protection circuits. These circuits provide various functions to protect the system, including soft start, drive signals mask, and power supply shut down.By using master-slave load current sharing technich, modules can be parrallzed easily, thus capacity-expansion is very convenient.Because of the high frequency operation, this switching mode power supply have many advantages:light weight,small physical size,high reliability,etc.更多还原