功率器件电力电子器件.pptVIP

Chapter 1 Power Electronic Devices;1.1 An introductory overview of power electronic devices; Features of power electronic devices ;2) Configuration of systems using power electronic devices; Terminals of a power electronic device Control signal from drive circuit must be connected between the control terminal and a fixed power circuit terminal (therefore called common terminal ;Major topics for each device Appearance, structure, and symbol Physics of operation Specification Special issues Devices of the same family Passive components in power electronic circuit Transformer, inductor, capacitor and resistor: these are passive components in a power electron ic circuit since they can not be controlled by control signal and their characteristics are usually constant and linear. The requirements for these passive components by power electronic circuits could be very different from those by ordinary circuits.;1.2 Uncontrolled device Power diode;PN junction ;PN junction with voltage applied in the forward direction;PN junction with voltage applied in the reverse direction;Construction of a practical power diode;Features different from low-power (information electronic) diodes –Larger size –Vertically oriented structure –n drift region (p-i-n diode) –Conductivity modulation Junction capacitor The positive and negative charge in the depletion region is variable with the changing of external voltage. variable with the changing of external voltage. —–Junction capacitor C Junction capacitor CJ . Junction capacitor influences the switching characteristics of power diode.;Static characteristics of power diode Turn-off transient Turn- on transient ; Examples of commercial power diodes ;1.3 Half- controlled device—Thyristor; Appearance and symbol of thyristor ; Structure and equivalent circuit of thyristor ; Physics of thyristor operation; Quantitative description of thyristor operation When IG =0,