Good day everyone, so I have a problem with my two switch forward converter. As soon as the current increases at the input from around 200mA a transient/spike starts appears at both the turn-on and turn-off of Vgs. The higher I go and push it the bigger the spikes ultimately get, which is problematic as I need to get up to around 2A and 323V at the input.
I've tried increasing Rg from 10 ohm I used to 82 ohms now and it did help a bit, haven't tried higher as its already quite high. I have a diode conducting back over Rg and a 10kOhm pull down resistor. I am using a HCPL 3120 as my gate driver. Adding a DC link capacitor very close to the switches did help take away some ringing after the spike.
In the image Vgs (Yellow) and Vpri (Blue) over the transformer.
If you have any suggestions on how I can get rid of it or dampen it I'd greatly appreciate.
Also attached a picture of my circuit
I've tried increasing Rg from 10 ohm I used to 82 ohms now and it did help a bit, haven't tried higher as its already quite high. I have a diode conducting back over Rg and a 10kOhm pull down resistor. I am using a HCPL 3120 as my gate driver. Adding a DC link capacitor very close to the switches did help take away some ringing after the spike.
In the image Vgs (Yellow) and Vpri (Blue) over the transformer.
If you have any suggestions on how I can get rid of it or dampen it I'd greatly appreciate.
Also attached a picture of my circuit
Attachments
-
125.3 KB Views: 7
-
130.3 KB Views: 8
-
131.7 KB Views: 10
-
230 KB Views: 9