tailieunhanh - Chapter 5: Power Electronics: Devices and Circuits

Power electronics is an enabling technology for all electrical and electronic apparatus requiring electric power to drive. Over the past twenty years, the power electronics industry has grown tremendously. Its growth is a result from increasing demand of reliable, efficient, compact and cost effective power supplies for telecommunication, computer, and motor drive industries as well as for medical equipments and military use. | Chapter 5 Power Electronics Devices and Circuits Introduction Power electronics is an enabling technology for all electrical and electronic apparatus requiring electric power to drive. Over the past twenty years the power electronics industry has grown tremendously. Its growth is a result from increasing demand of reliable efficient compact and cost effective power supplies for telecommunication computer and motor drive industries as well as for medical equipments and military use. This growth is facilitated by the significant improvement in semiconductor technology in which smaller packaging and higher power handling devices have been marketed. In response to the advancement in semiconductor and magnetics technology power electronics researchers and engineers have strived to thoroughly employ these technologies through new circuit design and topologies optimized control and packaging techniques in order to meet the industry demands. Power electronics is all about using electronic devices and circuits with storage element to control the level of voltage and current either in the form of AC or DC. Power electronics circuits are switching converters with periodic switching actions to process the electrical energy to meet the design specification. Apart from semiconductors inductor and transformer are the critical magnetic components in the power switching converter. Their functions such as storage element power splitting and safety isolation 83 5. Power Electronics Devices and Circuits 84 will be explained in detail in Chapter 6. In order to control power some form of control techniques are needed and will be discussed in Chapter 7. This chapter we will begin with the semiconductor devices used for power converters. We then analyze the basic DC DC converters at the steady state. That is the output voltage and current are at stable condition. Finally the operation of gate driver which drives the transistor is presented. Electrical Energy Conversion by .