igbt switching by solid state relay

[vishwa1]

dear all

I am using an igbt(1200vdc,30A) in dc control solid state relay,its switching well but the problem is, its getting heat up,so can any one tell me,how to avoid this heating problem.Vce drop is more 1volts,when igbt is in ON state.....

 

[davoud]

It is better that you show your circuit and specify it such as load current , load type (resistive, inductive or capacitive)....

 

[vishwa1]

yeah its resistive load,and here is the circuit,which I build.for testing purpose i have given only 12vdc for vcc.

 

[davoud]

what is your igbt part number ?
However a little hot temperature is normal but you can use heat-sink for cooling that.
Temperature build by Ic
https://www.google.com/url?sa=t&rct...8aBVn-1PqdMwJI-bQ&sig2=dg9Y8lLH6KStuhTPsM515g
Please clear more (temperature of igbt,part number....)

 

[FvM]

Vce drop is more 1volts,when igbt is in ON state.....

Yes, that's normal operation of an IGBT. If you want lower voltage drop, go for a MOSFET.

 

[vishwa1]

Part no is AP30G120SW.....And temperature going beyond the 110 degree Celsius.Is that normal temperature to operate IGBT ? It wont effect our pcb or not?..but its working well my worry is only heating problem....how to choose thew
heat sink ?......N thank you for the reply...

 

[FlapJack]

Your gate resistor is 220 ohms. That is way to high, your IGBT is taking much to long to turn on. Change it to a maximum of 22 ohms, and no smaller than 10 ohms.

Also OPTO couplers are very slow, and for that reason are rarely used in switching power supply's. Just guessing that OPTO is good for few KHZ

 

[FvM]

Your gate resistor is 220 ohms. That is way to high, your IGBT is taking much to long to turn on. Change it to a maximum of 22 ohms, and no smaller than 10 ohms.

Also OPTO couplers are very slow, and for that reason are rarely used in switching power supply's. Just guessing that OPTO is good for few KHZ

That' right, but I don't believe that the IGBT is actually operated with the circuit shown in post #3. It switches the IGBT only on but never off. In so far I wasn't able to identify it as a serious control circuit.

 

[vishwa1]

this time i have tried the circuit using tlp 250driver,instead of 4n35 coupler.but i m getting high Vce drop, its 3v.due to this the igbt is heating up.IGBT part NO is AP30G120SW,ACCORDING SPECIFICATION VCE DROP 3V.can any one tell me the how build circuit for this.

 

[FvM]

TLP250 with sufficient supply voltage, of 12 - 15 V is O.K. Voltage drop will be about 3V at 20A Ic according to IGBT specification, it's not a matter of gate driver circuit.

What are you exactly asking?

 

[vishwa1]

Actually i am asking that if Vce drop increases its effects our switching operation or not.if yes den how can we reduce that.