Inverter IGBT module power limit protection

Why is it important to design protection circuits for IGBT modules?

Since IGBT modules may be destroyed by overcurrent, overvoltage or other abnormality, it is necessary to design protection circuits. It is important when designing this circuits that module’s characteristics are fully taken into consideration, since an inappropriate circuit will allow the module to be destroyed.

How do I control the surge voltage on my IGBT?

Control the surge voltage with an additional protection circuit (snubber circuit) to the IGBT. A film capacitor in the snubber circuit, which is connected as close as possible to the IGBT, works to bypass the high frequency surge currents. Adjust the IGBT drive circuit’s – VGE and/or RG in order to reduce the di/dt value.

Can medium power drives use IGBT modules?

Medium power drives rated for greater than 100 kW can have IGBT modules. However, these modules may have gate charges up to 10 μC, necessitating high peak currents to turn on and off the IGBT. Gate driver ICs have limited peak current capability, typically 2.5 A for source and 5 A for sink.

How to reduce dI/dt value of IGBT drive circuit?

Adjust the IGBT drive circuit’s – VGE and/or RG in order to reduce the di/dt value. (Refer to Chapter 7, “Drive Circuit Design”.) Place the electrolytic capacitor as close as possible to the IGBT in order to reduce the parasitic inductance of the wiring. A low impedance capacitors have better effect.

What is the maximum current a single IGBT module can handle?

A single module of an IGBT is capable of handling currents up to 600 A in the dual configuration. The IGBT is a voltage controlled device, which gives it the ability to turn on and off very quickly. Paralleling IGBT modules becomes necessary when the output current requirement cannot be provided by a single IGBT module.

How to protect IGBT modules from static electricity?

In order to prevent this destruction, it is recommended that a 10KΩ resistor (RGE) be connected between the gate and the emitter. Furthermore, since IGBT modules have a MOS structure that is easily destroyed by static electricity, observe the following points of caution. When handling IGBTs, hold them by the case and do not touch the terminals.