How can i detect zero crossing of current for inductive load

[kam313]

I am controling the input (0-230v) of high voltag transformer (10 kva) using autotransformer, that is an expensive equipment, i want to know can i replace autotransformer with triac switching and also how can i detect current zero crossing in this case ? thanx in advance for your valueable thoughts.

 

[Tahmid]

For zero-crossing, check this:

https://www.edaboard.com/blog/1807/

However, you can not replace the auto transformer with triac-based circuit. For controlling the voltage (average voltage actually), you will use either phase angle control or pulse skipping modulation, both of which will mess up the sine wave. With phase angle control, you will get a distorted signal. With pulse skipping modulation, you will get a non-continuous signal. There are more problems associated.

These methods may work in some cases. However, the triac-based circuit will not be a replacement you can always expect to use.

Look into using AC-AC converters utilizing MOSFETs/IGBTs.

Hope this helps.
Tahmid.