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- 1. Power Electronics Power Electronics Chapter 1 Power Electronic Devices (Part I)
- 2. Power Electronic s 2 Outline Outline 1.1 An introductory overview of power electronic devices 1.1 An introductory overview of power electronic devices 1.2 Uncontrolled device 1.2 Uncontrolled device — — power diode power diode 1.3 Half 1.3 Half- -controlled device controlled device — — thyristor thyristor 1.4 Typical fully 1.4 Typical fully- -controlled devices controlled devices 1.5 Other new power electronic devices 1.5 Other new power electronic devices 1.6 Drive circuit for power electronic devices 1.6 Drive circuit for power electronic devices 1.7 Protection of power electronic devices 1.7 Protection of power electronic devices 1.8 Series and parallel connections of power electronic 1.8 Series and parallel connections of power electronic devices devices
- 3. Power Electronic s 3 The concept and features The concept and features Configuration of systems using power electronic devices Configuration of systems using power electronic devices Classifications Classifications Major topics Major topics 1.1 1.1 An introductory overview of power An introductory overview of power electronic devices electronic devices
- 4. Power Electronic s 4 Power electronic devices: Power electronic devices: In broad sense In broad sense Very often: Very often: Major material used in power semiconductor devices Major material used in power semiconductor devices —— —— Silicon Silicon are the electronic devices that can be directly used in the powe are the electronic devices that can be directly used in the power r processing circuits to convert or control electric power. processing circuits to convert or control electric power. The concept of power electronic devices The concept of power electronic devices power electronic devices power electronic devices Vacuum devices: Mercury arc Vacuum devices: Mercury arc rectifier rectifier thyratron thyratron, etc. . seldom , etc. . seldom in use today in use today Semiconductor devices: Semiconductor devices: major power electronic devices major power electronic devices Power electronic devices = Power semiconductor devices Power electronic devices = Power semiconductor devices
- 5. Power Electronic s 5 Features of power electronic devices Features of power electronic devices The electric power that power electronic device The electric power that power electronic device deals with is usually much larger than that the deals with is usually much larger than that the information electronic device does. information electronic device does. Usually working in switching states to reduce power Usually working in switching states to reduce power losses losses p=vi=0 Off-state Current through the device is 0 i=0 p=vi=0 On-state Voltage across the device is 0 v=0
- 6. Power Electronic s 6 Features of power electronic devices Features of power electronic devices Need to be controlled by information electronic circuits. Need to be controlled by information electronic circuits. Very often, drive circuits are necessary to interface Very often, drive circuits are necessary to interface between information circuits and power circuits. between information circuits and power circuits. Dissipated power loss usually larger than information Dissipated power loss usually larger than information electronic devices electronic devices — — special packaging and heat sink special packaging and heat sink are necessary. are necessary.
- 7. Power Electronic s 7 Power losses on power semiconductor Power losses on power semiconductor devices devices = conduction loss + turn = conduction loss + turn- -off loss + off off loss + off- -state loss + turn state loss + turn- -on loss on loss O n -s ta te (c o n d u c tio n s ta te ) tu rn in g - o ff O ff-s ta te (b lo c k in g s ta te ) tu rn in g -o n t t t v i p Total power loss on Total power loss on power semiconductor power semiconductor Switching loss Switching loss (on (on- -state loss) state loss)
- 8. Power Electronic s 8 Configuration of systems using power Configuration of systems using power electronic devices electronic devices Control circuit detection circuit drive circuit Power circuit (power stage, main circuit) Control circuit (in a broad sense) Power electronic system: Electric isolation: optical, magnetic Protection circuit is also very often used in power electronic system especially for the expensive power semiconductors.
- 9. Power Electronic s 9 Terminals of a power electronic device Terminals of a power electronic device C E G A power electronic device must have at least two terminals to allow power circuit current flow through. A power electronic device usually has a third terminal — —control terminal to control the states of the device. Control signal from drive circuit must be connected between the Control signal from drive circuit must be connected between the control terminal and a fixed power circuit terminal (therefore control terminal and a fixed power circuit terminal (therefore called common terminal ). called common terminal ). Drive Circuit
- 10. Power Electronic s 10 A classification of power electronic devices A classification of power electronic devices Uncontrolled device: diode Uncontrolled device: diode (Uncontrollable device) (Uncontrollable device) Fully Fully- -controlled device: Power MOSFET, IGBT,GTO, IGCT controlled device: Power MOSFET, IGBT,GTO, IGCT (Fully (Fully- -controllable device) controllable device) Half Half- -controlled device: controlled device: thyristor thyristor (Half (Half- -controllable device) controllable device) has only two terminals and can not be controlled by control signal. The on and off states of the device are determined by the power circuit. is turned-on by a control signal and turned-off by the power circuit The on and off states of the device are controlled by control signals.
- 11. Power Electronic s 11 Other classifications Other classifications power electronic devices power electronic devices Pulse Pulse- -triggered devices triggered devices Level Level- -sensitive (level sensitive (level- -triggered) devices triggered) devices power electronic devices power electronic devices power electronic devices power electronic devices Current Current- -driven (current driven (current- -controlled) devices controlled) devices Voltage Voltage- -driven (voltage driven (voltage- -controlled) devices controlled) devices (Field (Field- -controlled devices) controlled devices) Unipolar Unipolar devices (Majority carrier devices) devices (Majority carrier devices) Composite devices Composite devices Bipolar devices (Minority carrier devices) Bipolar devices (Minority carrier devices)
- 12. Power Electronic s 12 Appearance, structure, and symbol Appearance, structure, and symbol Physics of operation Physics of operation Characteristics Characteristics Specification Specification Special issues Special issues Devices of the same family Devices of the same family Major topics for each device Major topics for each device Switching characteristics Switching characteristics Static characteristics Static characteristics
- 13. Power Electronic s 13 Passive components in power electronic Passive components in power electronic circuit circuit Transformer, inductor, capacitor and resistor: Transformer, inductor, capacitor and resistor: these are passive components in a power electronic these are passive components in a power electronic circuit since they can not be controlled by control signal and circuit since they can not be controlled by control signal and their characteristics are usually constant and linear. their characteristics are usually constant and linear. The requirements for these passive components by power The requirements for these passive components by power electronic circuits could be very different from those by electronic circuits could be very different from those by ordinary circuits. ordinary circuits.
- 14. Power Electronic s 14 1.2 Uncontrolled device Power diode 1.2 Uncontrolled device Power diode Appearance Appearance Structure Structure Symbol Symbol Cathode Anode K K A A Anode Cathode
- 15. Power Electronic s 15 PN junction PN junction - 。 - 。 - 。 - 。 - 。 - 。 - 。 - 。 - 。 - 。 - 。 - 。 - 。 - 。 - 。 + · + · + · + · + · + · + · + · + · + · + · + · + · + · + · + - + - + - + - + - p region n region Direction of inner electric field Space charge region (depletion region, potential barrier region) Semiconductor (Column IV element, Semiconductor (Column IV element, Si Si) ) Electrons and holes. Electrons and holes. Pure semiconductor (intrinsic semiconductor) Pure semiconductor (intrinsic semiconductor) Doping, p Doping, p- -type semiconductor. N type semiconductor. N- -type semiconductor type semiconductor PN junction PN junction Equilibrium of diffusion and drift Equilibrium of diffusion and drift
- 16. Power Electronic s 16 PN junction with voltage applied in the PN junction with voltage applied in the forward direction forward direction V + + + + + - - - - - n p Wo W + -
- 17. Power Electronic s 17 PN junction with voltage applied in the reverse PN junction with voltage applied in the reverse direction direction + - V + + + + + - - - - - - - - + + + n p Wo W Effective direction of electronic field
- 18. Power Electronic s 18 Construction of a practical power diode Construction of a practical power diode Features different from low Features different from low- -power (information electronic) diodes power (information electronic) diodes – – Larger size – – Vertically oriented structure – – n drift region (p-i-n diode) – – Conductivity modulation 250μm Breakdown voltage dependent 10 μm p Nd =10 cm n substrate -3 19 Na =10 cm -3 19 + n epi Nd =10 cm -3 14 p Nd =10 cm n substrate -3 19 + Na =10 cm -3 19 + n epi - Nd =10 cm -3 14 i Anode Cathode + - V -
- 20. Power Electronic s 20 Reverse Reverse- -biased power diode biased power diode Breakdown Breakdown – – Avalanche breakdown – – Thermal breakdown
- 21. Power Electronic s 21 The positive and negative charge in the depletion region is 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 J . . Junction capacitor C Junction capacitor CJ J Junction capacitor influences the switching characteristics of Junction capacitor influences the switching characteristics of power diode. power diode. Junction capacitor Junction capacitor Diffusion capacitor Diffusion capacitor C CD D Potential barrier capacitor Potential barrier capacitor C CB B
- 22. Power Electronic s 22 Static characteristics of power diode Static characteristics of power diode The I The I- -V characteristic of power diode V characteristic of power diode I O IF UTO UF U
- 23. Power Electronic s 23 Switching (dynamic) characteristics of power Switching (dynamic) characteristics of power diode diode Reverse Reverse- -recovery process: recovery process: Reverse-recovery time, reverse-recovery charge, reverse-recovery peak current. Turn Turn- -off transient off transient IF UF tF t0 trr td tf t1 t2 t UR URP IRP diF dt diR dt
- 24. Power Electronic s 24 Switching (dynamic) characteristics Switching (dynamic) characteristics of power of power diode diode Forward recovery process: Forward recovery process: forward-recovery time Turn Turn- -on transient on transient UFP u i iF uF tfr t 0 2V
- 25. Power Electronic s 25 Specifications of power diode Specifications of power diode Average rectified forward current I Average rectified forward current IF(AV) F(AV) Forward voltage U Forward voltage UF F Peak repetitive reverse voltage U Peak repetitive reverse voltage URRM RRM Maximum junction temperature T Maximum junction temperature TJM JM Reverse Reverse- -recovery time recovery time t trr rr
- 26. Power Electronic s 26 Types of power diodes Types of power diodes General purpose diode (rectifier diode): General purpose diode (rectifier diode): Fast recovery diode Fast recovery diode Schottky Schottky diode ( diode (Schottky Schottky barrier diode barrier diode- -SBD) SBD) standard recovery Reverse recovery time and charge specified. trr is usually less than 1μs, for many less than 100 ns —— ultra-fast recovery diode. – A majority carrier device – Essentially no recovered charge, and lower forward voltage. – Restricted to low voltage (less than 200V)
- 27. Power Electronic s 27 Examples of commercial power diodes Examples of commercial power diodes
- 28. Power Electronic s 28 History and applications of power diode History and applications of power diode Applied in industries starting 1950s Applied in industries starting 1950s Still in Still in- -use today. Usually working with controlled use today. Usually working with controlled devices as necessary components devices as necessary components In many circumstances fast recovery diodes or In many circumstances fast recovery diodes or schottky schottky diodes have to be used instead of general diodes have to be used instead of general purpose diodes. purpose diodes.
- 29. Power Electronic s 29 1.3 Half 1.3 Half- -controlled device controlled device— —Thyristor Thyristor Another name: SCR Another name: SCR— —silicon controlled rectifier silicon controlled rectifier Thyristor Thyristor Opened the power electronics era Opened the power electronics era – – 1956, invention, Bell Laboratories 1956, invention, Bell Laboratories – – 1957, development of the 1st product, GE 1957, development of the 1st product, GE – – 1958, 1st commercialized product, GE 1958, 1st commercialized product, GE – – Thyristor Thyristor replaced vacuum devices in almost every power replaced vacuum devices in almost every power processing area. processing area. Still in use in high power situation. Still in use in high power situation. Thyristor Thyristor till has the till has the highest power highest power- -handling capability. handling capability. History History
- 30. Power Electronic s 30 Appearance and symbol of Appearance and symbol of thyristor thyristor Symbol Symbol Appearance Appearance K G A Cathode Cathode Anode Anode Gate Gate
- 31. Power Electronic s 31 Structure and equivalent circuit of Structure and equivalent circuit of thyristor thyristor • • Structure Structure • • Equivalent circuit Equivalent circuit
- 32. Power Electronic s 32 Physics of Physics of thyristor thyristor operation operation Equivalent circuit: A Equivalent circuit: A pnp pnp transistor and an transistor and an npn npn transistor transistor interconnected together interconnected together Positive feedback Positive feedback Trigger Trigger Can not be turned off by control Can not be turned off by control signal signal Half Half- -controllable controllable
- 33. Power Electronic s 33 Quantitative description of Quantitative description of thyristor thyristor operation operation I Ic1 c1= =α α1 1 I IA A + + I ICBO1 CBO1 （ （1 1- -1 1） ） I Ic2 c2= =α α2 2 I IK K + + I ICBO2 CBO2 （ （1 1- -2 2） ） I IK K= =I IA A+ +I IG G （ （1 1- -3 3） ） I IA A= =I Ic c1 1+ +I Ic c2 2 （ （1 1- -4 4） ） ) ( 1 2 1 CBO2 CBO1 G 2 A α α α + − + + = I I I I （ （1 1- -5 5） ） When I When IG G=0, =0, α α1 1+α +α2 2 is small. is small. When I When IG G>0, >0, α α1 1+α +α2 2 will approach 1, I will approach 1, IA A will be very large. will be very large.
- 34. Power Electronic s 34 Other methods to trigger Other methods to trigger thyristor thyristor on on High voltage across anode and cathode High voltage across anode and cathode— — avalanche breakdown avalanche breakdown High rising rate of anode High rising rate of anode voltagte voltagte — — du/dt du/dt too high too high High junction temperature High junction temperature Light activation Light activation
- 35. Power Electronic s 35 Static characteristics of Static characteristics of thyristor thyristor Blocking when reverse Blocking when reverse biased, no matter if there biased, no matter if there is gate current applied is gate current applied Conducting only when Conducting only when forward biased and there forward biased and there is triggering current is triggering current applied to the gate applied to the gate Once triggered on, will be Once triggered on, will be latched on conducting latched on conducting even when the gate even when the gate current is no longer current is no longer applied applied Turning off: decreasing Turning off: decreasing current to be near zero current to be near zero with the effect of external with the effect of external power circuit power circuit Gate I Gate I- -V characteristics V characteristics O U Ak IA I H IG2 IG1 IG =0 U bo U DSM U DRM U RRM U RSM forward forward conducting conducting avalanche avalanche breakdown breakdown reverse reverse blocking blocking increasing IG forward forward blocking blocking
- 36. Power Electronic s 36 Switching characteristics of Switching characteristics of thyristor thyristor Turn Turn- -on transient on transient – – Delay time t Delay time td d – – Rise time Rise time t tr r – – Turn Turn- -on time on time t tgt gt Turn Turn- -off transient off transient – – Reverse recovery Reverse recovery time time t trr rr – – Forward recovery Forward recovery time time t tgr gr – – Turn Turn- -off time off time t tq q 100% 90% 10% uAK t t O 0 td tr trr tgr URRM IRM iA
- 37. Power Electronic s 37 Specifications of Specifications of thyristor thyristor Peak repetitive forward blocking voltage U Peak repetitive forward blocking voltage UDRM DRM Peak repetitive reverse blocking voltage U Peak repetitive reverse blocking voltage URRM RRM Peak on Peak on- -state voltage U state voltage UTM TM Average on Average on- -state current I state current IT(AV) T(AV) Holding current I Holding current IH H Latching up current I Latching up current IL L Peak forward surge current I Peak forward surge current ITSM TSM du/dt du/dt di/dt di/dt
- 38. Power Electronic s 38 The family of The family of thyristors thyristors Fast switching Fast switching thyristor thyristor— —FST FST Triode AC switch Triode AC switch— —TRIAC TRIAC (Bi (Bi- -directional triode directional triode thyristor thyristor) ) Reverse Reverse- -conducting conducting thyristor thyristor Light Light- -triggered ( triggered (activited activited) ) thyristor thyristor — —RCT RCT — —LTT LTT I O U IG=0 K G A A G K G K A G T1 T2
- 39. Power Electronic s 39 1.4 Typical fully 1.4 Typical fully- -controlled devices controlled devices 1.4.1 Gate 1.4.1 Gate- -turn turn- -off off thyristor thyristor — —GTO GTO 1.4.2 Giant transistor 1.4.2 Giant transistor — —GTR GTR 1.4.3 Power metal 1.4.3 Power metal- -oxide oxide- -semiconductor field effect semiconductor field effect transistor transistor — — Power MOSFET Power MOSFET 1.4.4 Insulated 1.4.4 Insulated- -gate bipolar transistor gate bipolar transistor — —IGBT IGBT Features Features – – Begin to be used in large amount in 1980s Begin to be used in large amount in 1980s – – GTR is obsolete and GTO is also seldom used today. GTR is obsolete and GTO is also seldom used today. – – IGBT and power MOSFET are the two major power IGBT and power MOSFET are the two major power semiconductor devices nowadays. semiconductor devices nowadays. Applications Applications – – IC fabrication technology, fully IC fabrication technology, fully- -controllable, high frequency controllable, high frequency
- 40. Power Electronic s 40 A G K G G K N1 P1 N2 N2 P2 b) a) 1.4.1 Gate 1.4.1 Gate- -turn turn- -off off thyristor thyristor— —GTO GTO Major difference from conventional Major difference from conventional thyristor thyristor: : The gate and cathode structures are highly The gate and cathode structures are highly interdigitated interdigitated, with , with various types of geometric forms being used to layout the various types of geometric forms being used to layout the gates and cathodes. gates and cathodes. Structure Structure Symbol Symbol G K A
- 41. Power Electronic s 41 Physics of GTO operation Physics of GTO operation The basic operation of GTO is the The basic operation of GTO is the same as that of the conventional same as that of the conventional thyristor thyristor. . The principal differences lie in the The principal differences lie in the modifications in the structure to modifications in the structure to achieve gate turn achieve gate turn- -off capability. off capability. – – Large Large α α2 2 – – α α1 1+ +α α2 2 is just a little larger than is just a little larger than the critical value 1. the critical value 1. – – Short distance from gate to Short distance from gate to cathode makes it possible to cathode makes it possible to drive current out of gate. drive current out of gate. R NPN PNP A G S K EG IG EA IK Ic2 Ic1 IA V1 V2
- 42. Power Electronic s 42 Characteristics of GTO Characteristics of GTO Static characteristic Static characteristic – – Identical to conventional Identical to conventional thyristor thyristor in the forward direction in the forward direction – – Rather low reverse breakdown voltage (20 Rather low reverse breakdown voltage (20- -30V) 30V) Switching characteristic Switching characteristic O t 0 t iG iA IA 90%IA 10%IA tt tf ts td tr t0 t1 t2 t3 t4 t5 t6
- 43. Power Electronic s 43 Specifications of GTO Specifications of GTO Most GTO specifications have the same meanings Most GTO specifications have the same meanings as those of conventional as those of conventional thyristor thyristor. . Specifications different from Specifications different from thyristor thyristor’ ’s s – – Maximum controllable anode current I Maximum controllable anode current IATO ATO – – Current turn Current turn- -off gain off gain β βoff off – – Turn Turn- -on time t on time ton on – – Turn Turn- -off time off time t toff off
- 44. Power Electronic s 44 1.4.2 Giant Transistor 1.4.2 Giant Transistor— —GTR GTR GTR is actually the bipolar junction transistor that can handle GTR is actually the bipolar junction transistor that can handle high voltage and large current. high voltage and large current. So GTR is also called power BJT, or just BJT. So GTR is also called power BJT, or just BJT. Basic structure Basic structure Symbol Symbol b e c
- 45. Power Electronic s 45 Structures of GTR different from its Structures of GTR different from its information information- -processing counterpart processing counterpart Multiple Multiple- -emitter structure emitter structure Darlington configuration Darlington configuration
- 46. Power Electronic s 46 Physics of GTR operation Physics of GTR operation Same as information BJT device Same as information BJT device holes electrons Eb Ec ib ic =βib ie =(1+β )ib
- 47. Power Electronic s 47 Static characteristics of GTR Static characteristics of GTR cut-off region Amplifying (active) region O I ib3 ib2 ib1 ib1<ib2<ib3 Uce S a t u r a t io n r e g io n
- 48. Power Electronic s 48 Switching characteristics of GTR Switching characteristics of GTR Turn Turn- -on transient on transient – – Turn Turn- -on delay time t on delay time td d – – Rise time Rise time t tr r – – Turn Turn- -on time t on time ton on Turn Turn- -off transient off transient – – Storage time Storage time t ts s – – Falling time Falling time t tf f – – Turn Turn- -off time off time t toff off ib Ib 1 Ib 2 Ics ic 0 0 90%Ib1 10%Ib1 90%Ics 10%Ics t0 t1 t2 t3 t4 t5 t t toff ts tf ton tr td
- 49. Power Electronic s 49 Second breakdown of GTR Second breakdown of GTR
- 50. Power Electronic s 50 Safe operating area (SOA) of GTR Safe operating area (SOA) of GTR S O A O Ic Ic M P S B P c M U c e U c e M
- 51. Power Electronic s 51 1.4.3 Power metal 1.4.3 Power metal- -oxide oxide- -semiconductor field semiconductor field effect transistor effect transistor— —Power MOSFET Power MOSFET Basic structure Basic structure Symbol Symbol G S D P channel A classification A classification Field Effect Field Effect Transistor Transistor (FET) (FET) Metal Metal- -onside onside- -semiconductor FET (MOSFET) semiconductor FET (MOSFET) Power MOSFET Power MOSFET Junction FET (JFET) Junction FET (JFET) Static induction transistor (SIT) Static induction transistor (SIT) n channel n channel p channel p channel G S D N channel
- 52. Power Electronic s 52 Structures of power MOSFET Structures of power MOSFET Also vertical Also vertical structure structure— —VMOS VMOS – – VVMOS, VDMOS VVMOS, VDMOS Multiple parallel Multiple parallel cells cells – – Polygon Polygon- -shaped shaped cells cells A structure of hexagon cells A structure of hexagon cells
- 53. Power Electronic s 53 Physics of MOSFET operation Physics of MOSFET operation p-n- junction is reverse-biased off-state voltage appears across n- region Off Off- -state state
- 54. Power Electronic s 54 Physics of MOSFET operation Physics of MOSFET operation p-n- junction is slightly reverse biased positive gate voltage induces conducting channel drain current flows through n- region and conducting channel on resistance = total resistances of n- region, conducting channel,source and drain contacts, etc. On On- -state state
- 55. Power Electronic s 55 Static characteristics of power MOSFET Static characteristics of power MOSFET
- 56. Power Electronic s 56 Switching characteristics of power MOSFET Switching characteristics of power MOSFET Rs RG RF RL iD uGS up iD +UE iD O O O up t t t uGS uGSP uT td(on) tr td(off) tf Turn Turn- -on transient on transient – – Turn Turn- -on delay time t on delay time td(on) d(on) – – Rise time Rise time t tr r Turn Turn- -off transient off transient – – Turn Turn- -off delay time t off delay time td(off) d(off) – – Falling time Falling time t tf f
- 57. Power Electronic s 57 Specifications of power MOSFET Specifications of power MOSFET Drain Drain- -source breakdown voltage U source breakdown voltage UDS DS Continuous drain current I Continuous drain current ID D Peak pulsed drain current I Peak pulsed drain current IDM DM On (On On (On- -state) resistance R state) resistance RDS(on) DS(on) Inter Inter- -terminal capacitances terminal capacitances – – Short circuit input capacitance Short circuit input capacitance C Ciss iss= = C CGS GS+ + C CGD GD – – Reverse transfer capacitance Reverse transfer capacitance C Crss rss= = C CGD GD – – Short circuit output capacitance Short circuit output capacitance C Coss oss= = C CDS DS+ + C CGD GD SOA of power MOSFET SOA of power MOSFET – – No second breakdown No second breakdown
- 58. Power Electronic s 58 Examples of commercial power MOSFET Examples of commercial power MOSFET
- 59. Power Electronic s 59 Features and applications of power MOSFET Features and applications of power MOSFET Voltage Voltage- -driven device, simple drive circuit driven device, simple drive circuit Majority Majority- -carrier device, fast switching speed, high carrier device, fast switching speed, high operating frequency (could be hundreds of kHz) operating frequency (could be hundreds of kHz) Majority Majority- -carrier device, better thermal stability carrier device, better thermal stability On On- -resistance increases rapidly with rated blocking resistance increases rapidly with rated blocking voltage voltage – – Usually used at voltages less than 500V and power less Usually used at voltages less than 500V and power less than 10kW than 10kW – – 1000V devices are available, but are useful only at low 1000V devices are available, but are useful only at low power levels(100W) power levels(100W) Part number is selected on the basis of on Part number is selected on the basis of on- - resistance rather than current rating resistance rather than current rating
- 60. Power Electronic s 60 The body diode of power MOSFET The body diode of power MOSFET The body diode The body diode Equivalent circuit Equivalent circuit
- 61. Power Electronic s 61 1.4.4 1.4.4 Insulated Insulated- -gate bipolar transistor gate bipolar transistor — —IGBT IGBT Features Features • • On On- -state losses are much smaller than those of a power state losses are much smaller than those of a power MOSFET, and are comparable with those of a GTR MOSFET, and are comparable with those of a GTR • • Easy to drive Easy to drive — —similar to power MOSFET similar to power MOSFET • • Faster than GTR, but slower than power MOSFET Faster than GTR, but slower than power MOSFET Application Application • • The device of choice in 500 The device of choice in 500- -1700V applications, at power 1700V applications, at power levels of several kW to several MW levels of several kW to several MW Combination of MOSFET and GTR Combination of MOSFET and GTR GTR GTR: low conduction losses (especially at larger blocking volta : low conduction losses (especially at larger blocking voltages), ges), longer switching times, current longer switching times, current- -driven driven MOSFET MOSFET: faster switching speed, easy to drive (voltage : faster switching speed, easy to drive (voltage- -driven), driven), larger conduction losses (especially for hi larger conduction losses (especially for higher blocking voltages) gher blocking voltages) IGBT IGBT
- 62. Power Electronic s 62 Structure and operation principle of IGBT Structure and operation principle of IGBT Basic structure Basic structure Also multiple cell structure Also multiple cell structure Basic structure similar to Basic structure similar to power MOSFET, except power MOSFET, except extra p region extra p region On On- -state: minority carriers state: minority carriers are injected into drift region, are injected into drift region, leading to conductivity leading to conductivity modulation modulation compared with power compared with power MOSFET: slower switching MOSFET: slower switching times, lower on times, lower on- -resistance, resistance, useful at higher voltages useful at higher voltages (up to 1700V) (up to 1700V) E G C N+ N- a) P N+ N+ P N+ N+ P+ Emitter Gate Collector Injecting layer Buffer layer Drift region J3 J2 J1
- 63. Power Electronic s 63 Equivalent circuit and circuit symbol of IGBT Equivalent circuit and circuit symbol of IGBT Equivalent circuit Equivalent circuit Circuit symbol Circuit symbol G E C + - + - + - ID RN IC VJ1 ID Ron Drift region resistance G C E
- 64. Power Electronic s 64 Static characteristics of IGBT Static characteristics of IGBT O Active region Cut-off (forward blocking) region Saturation region (On region) Reverse blocking region IC URM UFM UCE UGE(th) UGE
- 65. Power Electronic s 65 Switching characteristics of IGBT Switching characteristics of IGBT IGBT turn-on is similar to power MOSFET turn-on The major difference between IGBT turn-off and power MOSFET turn-off: – There is current tailing in the IGBT turn-off due to the stored charge in the drift region. t t t 10% 90% 10% 90% UCE IC 0 O 0 UGE UGEM ICM UCEM tfv1 tfv2 toff ton tfi1 tfi2 td(off) tf td(on) tr UCE(on) UGEM UGEM ICM ICM current tail
- 66. Power Electronic s 66 Parasitic Parasitic thyristor thyristor and latch and latch- -up in IGBT up in IGBT Main current path Main current path pnp pnp transistor and the parasitic transistor and the parasitic npn npn transistor transistor compose a parasitic compose a parasitic thyristor thyristor inside IGBT. inside IGBT. High emitter current tends to latch the parasitic High emitter current tends to latch the parasitic thyristor thyristor on. on. Modern Modern IGBTs IGBTs are essentially latch are essentially latch- -up proof up proof Location of equivalent devices Location of equivalent devices Complete IGBT equivalent circuit Complete IGBT equivalent circuit
- 67. Power Electronic s 67 Specifications of IGBT Specifications of IGBT Collector Collector- -emitter breakdown voltage U emitter breakdown voltage UCES CES Continuous collector current I Continuous collector current IC C Peak pulsed collector current I Peak pulsed collector current ICM CM Maximum power dissipation P Maximum power dissipation PCM CM Other issues: Other issues: SOA of IGBT SOA of IGBT – – The IGBT has a rectangular SOA with similar shape to the The IGBT has a rectangular SOA with similar shape to the power MOSFET. power MOSFET. Usually fabricated with an anti Usually fabricated with an anti- -parallel fast diode parallel fast diode
- 68. Power Electronic s 68 Examples of commercial IGBT Examples of commercial IGBT
- 69. Power Electronic s 69 1.5 Other new power electronic devices 1.5 Other new power electronic devices Static induction transistor Static induction transistor — —SIT SIT Static induction Static induction thyristor thyristor — —SITH SITH MOS controlled MOS controlled thyristor thyristor — — MCT MCT Integrated gate Integrated gate- -commutated commutated thyristor thyristor — —IGCT IGCT Power integrated circuit and power module Power integrated circuit and power module
- 70. Power Electronic s 70 Static induction transistor Static induction transistor— —SIT SIT Another name: power junction field effect Another name: power junction field effect transistor transistor— —power JFET power JFET Features Features – – Major Major- -carrier device carrier device – – Fast switching, comparable to power MOSFET Fast switching, comparable to power MOSFET – – Higher power Higher power- -handling capability than power MOSFET handling capability than power MOSFET – – Higher conduction losses than power MOSFET Higher conduction losses than power MOSFET – – Normally Normally- -on device, not convenient (could be made on device, not convenient (could be made normally normally- -off, but with even higher on off, but with even higher on- -state losses) state losses)
- 71. Power Electronic s 71 Static induction Static induction thyristor thyristor— —SITH SITH other names other names – – Field controlled Field controlled thyristor thyristor— —FCT FCT – – Field controlled diode Field controlled diode Features Features – – Minority Minority- -carrier device, a JFET structure with an additional carrier device, a JFET structure with an additional injecting layer injecting layer – – Power Power- -handling capability similar to GTO handling capability similar to GTO – – Faster switching speeds than GTO Faster switching speeds than GTO – – Normally Normally- -on device, not convenient (could be made on device, not convenient (could be made normally normally- -off, but with even higher on off, but with even higher on- -state losses) state losses)
- 72. Power Electronic s 72 MOS controlled MOS controlled thyristor thyristor— —MCT MCT Essentially a GTO with integrated MOS Essentially a GTO with integrated MOS- -driven driven gates controlling both turn gates controlling both turn- -on and turn on and turn- -off that off that potentially will significantly simply the design of potentially will significantly simply the design of circuits using GTO. circuits using GTO. The difficulty is how to design a MCT that can be The difficulty is how to design a MCT that can be turned on and turned off equally well. turned on and turned off equally well. Once believed as the most promising device, but Once believed as the most promising device, but still not commercialized in a large scale. The future still not commercialized in a large scale. The future remains uncertain. remains uncertain.
- 73. Power Electronic s 73 Integrated gate Integrated gate- -commutated commutated thyristor thyristor — — IGCT IGCT The newest member of the power semiconductor The newest member of the power semiconductor family, introduced in 1997 by ABB family, introduced in 1997 by ABB Actually the close integration of GTO and the gate Actually the close integration of GTO and the gate drive circuit with multiple drive circuit with multiple MOSFETs MOSFETs in parallel in parallel providing the gate currents providing the gate currents Short name: GCT Short name: GCT Conduction drop, gate driver loss, and switching Conduction drop, gate driver loss, and switching speed are superior to GTO speed are superior to GTO Competing with IGBT and other new devices to Competing with IGBT and other new devices to replace GTO replace GTO
- 74. Power Electronic s 74 Power integrated circuit and power module Power integrated circuit and power module Two major challenges Two major challenges – – Electrical isolation of high Electrical isolation of high- -voltage components from low voltage components from low- - voltage components voltage components – – Thermal management Thermal management— —power devices usually at higher power devices usually at higher temperatures than low temperatures than low- -voltage devices voltage devices Integration of power electronic devices Monolithic integration: Monolithic integration: power integrated circuit power integrated circuit Packaging integration: Packaging integration: power module power module Smart power integrated circuit(Smart power IC, SPIC, Smart switch) High voltage integrated circuit (HVIC) Ordinary power module:just power devices packaged together Integrated power electronics Module(IPEM): power devices, drive circuit, protection circuit, control circuit Intelligent power module (IPM): power devices, drive circuit, protection circuit
- 75. Power Electronic s 75 Review of device classifications Review of device classifications power electronic power electronic devices devices Pulse Pulse- -triggered devices: triggered devices: thyristor thyristor, GTO , GTO Level Level- -sensitive (Level sensitive (Level- -triggered) devices: triggered) devices: GTR,power MOSFET, IGBT, SIT, SITH, GTR,power MOSFET, IGBT, SIT, SITH, MCT, IGCT MCT, IGCT power electronic power electronic devices devices power electronic power electronic devices devices Current Current- -driven (current driven (current- -controlled) devices: controlled) devices: thyristor, GTO, GTR Voltage Voltage- -driven (voltage driven (voltage- -controlled) devices controlled) devices (Field (Field- -controlled devices):power MOSFET, controlled devices):power MOSFET, IGBT, SIT, SITH, MCT, IGCT IGBT, SIT, SITH, MCT, IGCT Uni Uni- -polar devices (Majority carrier devices): polar devices (Majority carrier devices): SBD, power MOSFET, SIT SBD, power MOSFET, SIT Composite devices: IGBT, SITH, MCT Composite devices: IGBT, SITH, MCT Bipolar devices (Minority Bipolar devices (Minority carrier devices): carrier devices): ordinary power diode, ordinary power diode, thyristor thyristor, GTO, GTR, , GTO, GTR, IGCT, IGBT, SITH, MCT IGCT, IGBT, SITH, MCT
- 76. Power Electronic s 76 Comparison of the major types of devices Comparison of the major types of devices Power Power- -handling capability handling capability
- 77. Power Electronic s 77 Comparison of the major types of devices Comparison of the major types of devices Maximum allowed current density as a function of Maximum allowed current density as a function of the switching frequency the switching frequency