2 The ways which the switchbeing overstressed inapplications（电力电子器件承受的过度冲击的方式/类型）Five possibilities foroverstresses:Overvoltage and high dvldt at turn-off.Overcurrent and high di/dt at turn-on,Excessivepowerdissipation
2 The ways which the switch being overstressed in applications (电力电子器件承受的过度冲击的方式/类型) Five possibilities for overstresses： Overvoltage and high dv/dt at turn-off, Overcurrent and high di/dt at turn-on, Excessive power dissipation
>Snubber circuit can be added to the basic converterto reduce the stresses to safe levelsixThe di/dt is limited by adding a series inductor LsCThe dvldt is limited bsyconnecting a capacitor C
➢Snubber circuit can be added to the basic converter to reduce the stresses to safe levels. i Ls The di/dt is limited by adding a series inductor Ls C The dv/dt is limited bsy connecting a capacitor Cs
3 Snubber'sFunction☆:Protectsemiconductordevices by:>Shaping the switching trajectory of the device as itturns on/off and lows the device dissipation（改变器件开通/关断轨迹来降低器件的开关损耗）>Limiting device yoltaaes during turn-off transients>Limiting the rate-of-rise (dvldt) of voltages across thesemiconductor device at device turn-off(限制器件关断期间承受的电压和承受的dvldt)
3 Snubber’s Function ☆ : Protect semiconductor devices by: ➢Shaping the switching trajectory of the device as it turns on/off and lows the device dissipation. (改变器件开通/关断轨迹来降低器件的开关损耗) ➢Limiting device voltages during turn-off transients ➢Limiting the rate-of-rise (dv/dt) of voltages across the semiconductor device at device turn-off. (限制器件关断期间承受的电压和承受的dv/dt)
3 Snubber'sFunction☆:Protectsemiconductordevices by:>Limiting device currents during turn-on transients>Limiting the rate-of-rise (di/dt) of currents through thesemiconductordevice atdeviceturn-on（限制器件开通期间承受的电流和承受的di/dt）
3 Snubber’s Function ☆ : Protect semiconductor devices by: ➢Limiting device currents during turn-on transients ➢Limiting the rate-of-rise (di/dt) of currents through the semiconductor device at device turn-on (限制器件开通期间承受的电流和承受的di/dt)
4TypesofSnubber Circuits☆(1)Unpolarized R-C snubbers(无极性RC缓冲电路Used to protect diodes and thyristors by limiting themaximum voltage and dvldt at reverse recoveryOT11本+RSA6Dr4CsBCSwsnubberO1A
11 4 Types of Snubber Circuits ☆ (1) Unpolarized R-C snubbers (无极性RC缓冲电路) Used to protect diodes and thyristors by limiting the maximum voltage and dv/dt at reverse recovery - + Df Rs Cs L Vd Io Sw snubber 1 3 5 4 6 2 - + - - Rs A B id C P vcn + van vbn + L L L Cs