Hello!
At work i repair CNC plasma cutters and we have a SAF oerlikon 300A power source.
The mains voltage is feed to a transformer and from that it gets rectified and smoothed out.
The DC voltage is feed to a so-called chopper unit that is basically a pwm regulator...
the chopper unit has two brick IGBT's mounted on a heatsink... anyway a unit has died (the IGBT's blew) and i had to repair it.... the interesting thing that catched my eye was the switching principle of the IGBT's...
they are 180 degrees out of phase. Each igbt is rated for 1200V and 400A current
so my question is why are the IGBT's switching out of phase and why use two if one can handle the current?
Thank you!
At work i repair CNC plasma cutters and we have a SAF oerlikon 300A power source.
The mains voltage is feed to a transformer and from that it gets rectified and smoothed out.
The DC voltage is feed to a so-called chopper unit that is basically a pwm regulator...
the chopper unit has two brick IGBT's mounted on a heatsink... anyway a unit has died (the IGBT's blew) and i had to repair it.... the interesting thing that catched my eye was the switching principle of the IGBT's...
they are 180 degrees out of phase. Each igbt is rated for 1200V and 400A current
so my question is why are the IGBT's switching out of phase and why use two if one can handle the current?
Thank you!