开关模式中功率半导体的应用-------外文资料翻译.doc

The electric energy is not normally used in the form in which it was produced or distributed. Practically all electronic systems require some form of energy conversion. A device that transfers electric energy from a given source to a given load using electronic circuits is referred to as Power Supply.
A typical application of a power supply unit (PSU) is convert utility AC voltage into regulated DC voltage required for electronic equipment. Nowadays in PSU the energy flow is controlled with semiconductors that are continuously switching on an off with high frequency. Such devices are referred to as switch mode power supplies or SMPS. They offer greater efficiency compared with linear supplies because a switch can control energy flow with low losses: when a switch is off, it blocks the flow of voltage and current, can be relatively low in both states. SMPS are also smaller in size and lighter in weight due to the reduced size of passive components and lower heat generation. The industry tended toward miniaturization, advancements in semiconductor technology, as well as various energy efficiency regulations have made "switch" the dominant type of PSR across practically the full spectrum of applications. Most of the switchers manufactured today for AC input applications include a PFC front end.


电能通常不会用在其生产或分布的形式。几乎所有的电子系统需要某种形式的能量转换。通过电路把电能从一个特定源转移到一个特定负载所用的设备称作为电源。
电源装置(PSU)的典型应用是将交流电转换成电子设备所需直流电。如今在电源装置，能量流通过不间断高频半导体开关来控制。这种装置被称为开关电源。与线性电源相比，他们能提供更大的效率，因为开关可以低损耗地控制能量：当开关关闭时，它会阻止电压和电流的流动，在两种状态中均比较低。同时，开关电源的尺寸较小，重量较轻，从而减少了无源元件的尺寸，降低了热量的产生。小型化倾向的行业，随着半导体技术的发展进步，同时各种能量效率的控制使得“开关” 得到了全方位的应用，在压力-状态-响应中占主导地位。大部分的切换开关早就了今天包括PFC前端末端在内的交流输入的应用。