IGBT门极驱动：电流和功率

1、ZH Liang-Al AP05 Dec 2003for internal use onlyInfineon Technologies Asia PacificPage 1Infineontechnologies Max. driver currentmaxAUG(min)A"=30S±15?RG(min厂RG QXtom*RG mbm + Ro grjverDrivepower仏*仏广盒5f - switch frequencyIGBT Gate Drive: Current & PowerCiS - input capacity (data sheet) P加苗

2、 -driver dissipation (depends of driver) Values of Cjes & Cres are given in IGBT data sheet. The factor of 5 (or 6) is used due to the effect of Cres (high AV, high AQ).ZH Liang-Al AP05 Dec 2003for internal use onlyInfineon Technologies Asia PacificPage #InfineontechnologiesIGBT Gate Drive: Gate

3、 Resistors It is necessary to use gate resistors (Rg) because the switching speed should be limited in order to reduce di/dt & dv/dt and hence over-voltage & EMI problem. To set switch-on & switch-off time separately, Rg can be split into Rg_oN and Rg_OFF-The cost of using Rg is the in c

4、rease of switchi ng losses.ZH Liang-Al AP05 Dec 2003for internal use onlyInfineon Technologies Asia PacificPage 4InfineontochnoloaiesIGBT Gate Drive: Power SuppliesPage 5With Single Power SupplyWith Dual Power SuppliesInfineon Technologies Asia Pacific Gate driving voltage for IGBT turn-on is normal

5、ly +15V. Gate driving voltage for IGBT tuiTkoff can be OV or negative (-5V to-15V). Negative gate driving voltage helps IGBT switch off faster & remain in off state, but itneeds dual power supplies. Whether to use OV or negative gate driving voltage depends on the requirement on cost & perfo

6、rma nee.for internal use onlyZH Liang-Al AP05 Dec 2003InfineontechnologiesIGBT Gate Drive: Interface Opto-couplers is commonly used as interfacing devices for applications where both signal transmission and potential isolation are required. Opto-couplers offers reliable isolation between IGBT (high-

7、potential) & microcontroller (lowpotential). Opto-couplers has long signal delay (jus) and is expensive.InfineontechnologiesIGBT Gate Drive: Half-bridge Drive Stan dard con fig u rati on: 2 drivers, 2 power supplies, 2 opto-couplers Advantages: standard, reliableDisadvantages: using opto-coupler

8、s, higher system costZH Liang-Al AP05 Dec 2003for internal use onlyInfineon Technologies Asia PacificPage 7ZH Liang-Al AP05 Dec 2003for internal use onlyInfineon Technologies Asia PacificPage #ZH Liang-Al AP05 Dec 2003for internal use onlyInfineon Technologies Asia PacificPage #InfineontochnoloaiesI

9、GBT Gate Drive: Half-bridge Drive In half-bridge IGBT drive, opto-couplers offer two functions: (1) safety isolation & (2) shifting the potential of the gate signal from pC potential to high-side potential. If safety isolation between IGBT & micro-controller is notneeded, then “Level Shift”

10、can replace opto-coupling and realize function (2).ZH Liang-Al AP05 Dec 2003for internal use onlyPage 8Infineon Technologies Asia PacificZH Liang-Al AP05 Dec 2003for internal use onlyPage #Infineon Technologies Asia PacificZH Liang-Al AP05 Dec 2003for internal use onlyPage #Infineon Technologies Asi

11、a PacificInfineontechnologiesIGBT Gate Drive: Level ShiftZH Liang-Al AP05 Dec 2003for internal use onlyPage 9Infineon Technologies Asia PacificZH Liang-Al AP05 Dec 2003for internal use onlyPage #Infineon Technologies Asia PacificZH Liang-Al AP05 Dec 2003for internal use onlyPage #Infineon Technologi

12、es Asia PacificInfineonIGBT Gate Drive: CJNEWZH Liang-Al AP05 Dec 2003for internal use onlyPage 11Infineon Technologies Asia PacificInfineontochnoloaiesIGBT Gate Drive: Boot-strap Boot-strap circuit includes only a diode and a capacitor. In half-bridge drive, the boot-strap circuit can replace the h

13、igh-side power supply and make single-supply operation possible. When the low-side IGBT (or FWD) is ON, the diode is forward biased and the capacitor is charged by the low-side power supply via the low-side IGBT and stores the energy. When the low-side IGBT (and FWD) is OFF, the diode is reverse bia

14、sed and blocks the DCbus voltage to protect the low-side circuit. Meanwhile, the capacitor supplies energy to the high-side driver.The boot-strap capacita nee should be high eno ugh to keep the supply voltage stable. Capacitanee needed can be calculated based on the working conditions and device par

15、ameters.ZH Liang-Al AP05 Dec 2003for internal use onlyPage 12Infineon Technologies Asia PacificInfineontochnologiesIGBT Gate Drive: Boot-strap CircuitConventional亠vccFeatures 3 high-side power supplies 1 low-side power supplyUsinq bootstrap circuit 3 diodes & capacitors 1 low-side power supply S

16、aving 3 PS (transformer cost) Reducing wiring & connection Diode: ultra-fast recovery Capacitor: general-purposed Dependent on low-side IGBTBenefitsZH Liang-Al AP05 Dec 2003for internal use onlyPage 14Infineon Technologies Asia PacificIGBT Gate DriveInfineontochnoloaiesNotes: Dead Time; VG Spike

17、s in OFF State.05 Dec 2003Page 13 Infineon Technologies Asia Pacificfor internal use onlyInfineontochnoloaiesIGBT Gate Drive: SummaryZH Liang-Al AP05 Dec 2003for internal use onlyPage 14Infineon Technologies Asia PacificZH Liang-Al AP05 Dec 2003for internal use onlyPage #Infineon Technologies Asia P

18、acific Driver is needed in order to charge/discharge IGBT parasitic capacitors fast eno ugh, hence to switch IGBT on/off fast enough. Gate resistor Rg is necessary to use to limit switching speed. It can be split into Rg 0N and Rg OFF to control IGBT turn-on & turn-off separately. Single or dual

19、 power supplies can be used for gate drive, depending on whether negative gate voltage is needed. Optocouplers is standard interfacing devices, however, it can be saved by using Level Shift driver (if safety isolation is not required) or new CLT driver. Bootstrap circuit can replace the high-side po

20、wer supply for simplicity & cost reduction. Dead time must be considered in half-bridge IGBT drive. Vg spikes can be compensated by using negative turn-off voltage.InfineontechnologiesElectricalFAILUREOver Voltage(VcE > VcES / Vge > Vges)A VCE = di/dt x< Stray Inductance< Fast Switch

21、ing< PS Failure< Short CircuitOver Temperature(Lunction > 0°C)< Over CurrentIGBT Protection: Failure Mechanism (Electrical)ZH Liang-Al AP05 Dec 2003for internal use onlyPage 16Infineon Technologies Asia Pacific< Poor Cooling< Low Gate VoltageTj=Tc + Ptot x RthJC Tc = Th 十 Ptot

22、 x RthCH Th = 丁人 + Ptot x thHAPtot: IGBT jPowq尸 Lossp = p + pr tot r Cond rSWPcond： VcESat，/C，加 Psw： Eqh , EojpfswIPOSIMZH Liang-Al AP05 Dec 2003for internal use onlyPage #Infineon Technologies Asia PacificInfineontochnoloaiesIGBT Protection: Short-circuit CapabilityPage 16 Unprotected short circuit

23、 causes IGBT junction overheat and hence chip burn-out. NPT IGBT chips limit the short-circuit (SC) current at 6-8 times (IGBT-2) or 4 times (IGBT-3) that of nominal current value under 15V gate voltage. NPT IGBT chip can withstand the SC current for 10 |ns. eupec guarantees no failure of IGBT under

24、 4 times that of nominal cur re nt within 10 ills (as shown in data sheets).for internal use only Infineon Technologies Asia PacificZH Liang-Al AP05 Dec 2003InfineontechnologiesIGBT Protection: Short-circuit ProtectionPower-up, shunt-down, driver failure Monitoring VCE in ON state % sat control to d

25、etect a sc currentGate Emitter resistor RGE for uncontrolled charging of CiesInfineontochnologiesIGBT Protection: Short-circuit ProtectionShunt resistor measurement in emitters to detect inverter current.Shunt resistor measurement in the output phases to detect inverter current. Shunt resistor in DC

26、 BUS Depends on module configuration Simple, low-cost, for lower power InfineontochnologiesShunt resistor measurement in the output phases to detect inverter current.Current measurement with current transducer to detect phase currentIGBT Protection: Over-current ProtectionZH Liang-Al AP05 Dec 2003fo

27、r internal use onlyPage 19Infineon Technologies Asia Pacific Shunt resistor in DC BUSCurrent sensor in DC BUS to detect sc currentInfineontechnologiesT/°CR/k。25.05.00030.04 1563&03.47240.02.91445.02 4F85002 08355.01.77360.01.51565.01.30070.01.1207500 968380.00 840485.00.731990.00.63979500 5

28、608100.00.4933105.00.4352110 00 38S1115 00 3418120.00.3042125.00.2714130 00 2428135.00.2178140.00.1959145 00 1765150.00.1595IGBT Protection: Over-temperature ProtectionInfineontochnologiesIGBT Protection: Under-voltage Protection25A KE30:00,51?52;02,53,0VCEV3t5404,5Low gate voltage causes high Vce_s

29、at & high conduction loss.so voltage is too low.Many drivers have the built-in function of under-voltage lock-out (UVLO)- to turn off the IGBT when supply些 IGBT Protection: Over-voltage of VGE & VceVGE over voltage can be resulted from failure of power supply or charging of Miller capacitor via Rg off件 can cause the damage of the gate insulation or drastic in crease of the short-circuit curre nt. Possible causes of VCE over voltage: Fast SC turn-off & high stray in