Dear Reza,

I want to build a system for controlling 10kwatt resistive load(Light) with phase control method and PWM
I searched the forum and found this informative message by
Mr Michael Karas

The link that you metioned shows PWM technique for power control. This technique will work very well on heaters etc. but on light it may not work. Even a missing half cycle will be noticed as flicker in light. Human eyes are very sensitive to slight change in thyristor firing angles too.

1).What is better for my system,TRIAC or IGBT?

A triac will do the job very well All you need to do is do the firing phase control for power control. For 10kWatt I will recommend using SCR Modules [ Thyristors ] Each block contains two SCRs connected back to back For 10kWatt @ 230Volts something like Semikron SKKT56 or SKKT92 will do the job www.semikron.com

IGBT is not really required here IMHO.

2).Do i must turning the lamps off on the mains zero crossing?
With Triac and SCR you only have turn on control no turn off control. These devices turn of automatically when the current goes below holding current. Every half cycle you need to trigger them to turn on.

3).For EMI what i must do?

You should do everything you can. Read Eriks noise reduction methods in FAQ's. Connect a snubber directly onto your thyristor be sure to use X2 grade caps.

Regards,
Prahlad Purohit