IGBT for AC switching

[vdmagar]

I want to switch AC waveforms using IGBT for capacitor switching...
Is it possible?

 

[lw1ecp]

I would add a bridge rectifier to the IGBT. Connect the IGBT to the bridge's DC terminals.
You want to switch capacitors?. As with any bipolar, MOS, IGBT, SCR or Triac, beware of high peak currents when the device turns on.

 

[vdmagar]

But as IGBT conduct current only in one direction...then how can we conduct for next half cycle?

 

[FvM]

You need a series-parallel cirucit with rectifiers, involving doubled losses. Capacitors for automatic PF compensation are usually switched by contactors or thyristors.

 

[lw1ecp]

FvM is right, if you are switching PF capacitors, you'd better use more rugged devices such as mechanical contacts or thyristors. Maybe thyristors would be advantageous thanks to their self-turnoff at zero current crossing. You don't need the fast response of IGBTs. An added bonus of thyristors is they are less prone to destruction from high voltage spikes: though this is NOT the way to turn them on, if you exceed the breakdown voltage they will just conduct; an IGBT, MOS or bipolar could die.
Anyway, my post was about how to simulate a bidirectional device with a unidirectional one. Think of the "AC" bridge's terminals as the "main terminals" of a TRIAC, and connect a bipolar, MOS, IGBT or SCR to the "DC" terminals: the device will always see the same polarity, but will be effectively switching AC to your load.
OR, do as FvM says: two transistors, in anti-parallel connection, each with a series diode, and excite each gate-emitter with separate isolated drivers.

 

[FvM]

Bridge rectifiers are an option, but in power applications, it's forward voltage drop would be highly unwanted. The same with AC switching by IGBT or MOSFET, that always implies a series connection of two devices, so the voltage drop is doubled.