It represents an external resistance. It excludes the module’s built-in RG(int).
Some of the ways to prevent misfiring of an IGBT are as follows: (1) by adding a capacity component CGE to the area between the gate and emitter (2) by increasing –VGE (3) by increasing gate resistance (RG) The effectiveness of these measures will vary depending on the applicable gate circuit, so please verify thoroughly […]
There are four basic precautions, shown below, when connecting IGBT modules in parallel: (1) Current unbalance control during steady operation (2) Current unbalance control at the time of switching (3) Gate drive circuit (4) Derating For details, refer to Application Manual Chapter 4-3.5 and Chapter 8.
One way to determine the validity of the dead-time setting is to verify the current on the direct current power line during non-loading time. For details, refer to Application Manual Chapter 7.
To prevent a short-circuit in the upper and lower arms, it is necessary to set an on-off timing delay between the several arms. During this time period both devices are switched off. The dead-time needs to be set so that it is generally longer than the switching time of the IGBT (toff max.). For details, […]
IGBT’s short-circuit current is impacted by gate-to-emitter voltage VGE, junction temperature Tj, and switching voltage Vcc. Generally, a short-circuit current increases with a large VGE, low Tj, and large Vcc.
Refer to Application Manual Chapter 7-5. It provides precautions regarding the photo-coupler’s noise capability, wiring between the drive circuit and IGBT, and gate overvoltage protection.
Please apply a reverse-bias voltage (-VGE) of -5 V or higher (-15 V recommended; max. -20 V) between the gate and emitter in the IGBT that is not being used. An insufficient reverse-bias voltage (-VGE) may cause the IGBT to misfire due to dV/dt at the time of reverse-recovery of the FWD, resulting in damage. […]
An insufficient reverse-bias voltage (-VGE) between the gate and emitter may cause the IGBT to mis-fire, leading to a short-circuit current. If the current is cut off the surge voltage and the generated loss may damage the product. For details, refer to Application Manual Chapters 4-3.3 and 7-1.2.
A larger gate resistance (RG) will increase switching loss, and make it more prone to generating an arm short circuit due to an insufficient dead-time. A smaller gate resistance (RG)may cause a sudden surge voltage. For details, refer to Application Manual Chapters 2-2.2 and 7-1.3.
