What functions do the IGBT Simulator have?

The IGBT Simulator can estimate the power loss and temperature for a 3-phase 2-level inverter circuit, 3-phase 3-level inverter circuit, and chopper circuit of an IGBT and FWD. It can also calculate loss and temperature under variable inverter operation conditions such as output current and switching frequency. Changes in loss and temperature when the load […]

How do I calculate IGBT losses?

Fuji provides a free software to calculate the IGBT losses. The following steps can be followed to obtain the figure. (1) Download our Loss Simulator (2) Launch our Loss Simulator (3) Enter data on the chip series, circuit configuration, voltage rating, and current rating. Select your model type. Click “”Next”” (4) Enter data on the […]

Is there a temperature dependency in the IGBT’s maximum collector-emitter voltage (VCES)?

A lower temperature reduces the IGBT’s maximum collector-emitter voltage (VCES). The data sheet describes the maximum collector-emitter voltage (VCES) under the condition of Tj=25oC. Refer to the technical information describing temperature dependency included in the technical documents under Design Support.

What is the lowest operation temperature for an IGBT module?

The minimum temperature is specified by the storage temperature (Tstg). Please consider that there will be a reduced device withstand voltage and peripheral component (capacitor, control circuit) characteristics under low temperature before use.

What precautions need to be considered when designing an IGBT drive circuit?

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.

Can application of a reverse-bias voltage (-VGE) on a gate-to-emitter be exempted in a case where only an FWD is used without an opposite IGBT, such as in a chopper circuit?

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. […]

What is the reason for applying reverse-bias voltage (-VGE) between the gate and emitter?

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.

Which terminal should be used to measure the collector-emitter voltage (VCE) when switching?

Please measure at the main terminal of the product. If a terminal is separately specified for measurement in the data sheet, please use the specified terminal.

What are the points we need to be aware of when determining the gate resistance (RG)?

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.

How can the surge voltage be reduced?

A surge voltage is generated by high di/dt, and wiring inductance outside the module, at the time of switching (L*di/dt). Some of the ways to suppress this problem are as follows: (1) Add a protective circuit (2) Reduce di/dt by adjusting RG or –VGE (3) Reduce inductance by making the main circuit wiring thicker and […]