Hello,
I am designing a High power dissipation board that consist of Parallel and Series connected Resistive load,I Considering the use of High Power IGBT Module to do so so as I can get a Linear Load curve using PWM Switching.

Input AC- 415
Topology- Star
O/P DC From Rectifier-560~600v
Load Power-30KW

 

And?

I'm out of cookies.

 

Hello,
I am designing a High power dissipation board that consist of Parallel and Series connected Resistive load,I Considering the use of High Power IGBT Module to do so so as I can get a Linear Load curve using PWM Switching.

Input AC- 415
Topology- Star
O/P DC From Rectifier-560~600v
Load Power-30KW

Switching speed is the downside with IGBTs - they were developed for the VCEsat of a bipolar transistor because it was lower than MOSFETs of the time and caused lower on time losses. Its basically a MOSFET driving an emitter follower in the manner of a hybrid Szicklai pair. You basically shift the on time losses to the transition time losses.

Modern MOSFETs have much lower RDSon, so don't just dismiss them as irrelevant before deciding what to use.

 

Switching speed is the downside with IGBTs

In high power higher frequency applications that was once sort of an issue but IGBT design has came a long way and now half bridge devices that can handle 1200 volts at several hundred amps on hard switching frequency of 50 - 100 KHz are common items. 100 - 200 KHz devices for the 00 - 600 volt multi tens to low hundreds of amps capacity are available as well.

As for the OP, given all he is working with is three phase rectified AC using a basic line frequency X6 clock rate would be more than fast enough.

To be honest given the application I would skip the rectification altogether and just use standard phase angle firing control with either reversed parallel SCRs or triacs on each phase.

 

In high power higher frequency applications that was once sort of an issue but IGBT design has came a long way
.

They did away with the emitter follower output section?!!!

 

I don't know how they did it.

I just know that when I used to work as a service tech at a welding supply center a good 10 - 12 years ago 1200 volt 100 - 200 hundred amp rated IGBTs that could run at 50 - 100 KHz hard switching, and lower rated devices that could run double that frequency band, were standard issue components in inverter based welders and plasma cutters.

I even did a few personal rebuilds of older machines replacing power mosfets with the high speed IGBTs models I saw in the newer units and they showed substantial decreases in heat sink temperatures on top of having typically double the working voltage and current ratings of the mosfets they replaced.

In my books anything that can run 50+ KHz at 600+ VDC and several hundred amps package capacity ain't slow or weak in my book!

 

I don't know how they did it.

I just know that when I used to work as a service tech at a welding supply center a good 10 - 12 years ago 1200 volt 100 - 200 hundred amp rated IGBTs that could run at 50 - 100 KHz hard switching, and lower rated devices that could run double that frequency band, were standard issue components in inverter based welders and plasma cutters.

!

When I repaired PC monitors for a living; I encountered a few models that the designer had not understood the frequency limitations of IGBTs, they'd designed for the highest frequency (they thought) they could get away with to minimise size and cost of the magnetics.

Those models paid the rent for quite a while. When my stock of IGBTs dwindled I started using ordinary MOSFETs - there were no consequences.

They're pretty much standard equipment for motor drives that don't use high frequency PWM, but I suspect the manufacturers are eager to recover their investment, and push them for applications where other devices might be a better choice.