3 Phase SCR (thyristor) for duct heater

[spbdasan]

Hi,

One of my project require to use thyristor for duct heater, but my client requirement is 1.thyristor should modulate output power through zero crossing and phase angle control 2. active harmonics filter to minimize THD to less than 5% 3. thyristor and active harmonics filter is compatible with high impedance netral earthing system, otherwise provide isolating transformer. below are the specifications
Voltage 415/3/50HZ, ( high impedance neutral earthing system)
Control 4-20mA.
heater - 15KW.

I have checked in locally about this, but most of the manufacture no reply.
someone pls give me solution on this to choose correct SCR controller, if possible please suggest any brand .

Thanks In advance.

 

[Jamzie]

As an example, have a look at reo.co.uk, they do plenty of controllers - a tad over complicated for a basic duct heater but gives you an idea

 

[Gage]

Have a look into Thyristor Stacks and controllers, plenty of them around.