mrinalmani
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Hi
I am testing a full bridge inverter running at approx 100KHz driven by a 12V source. The bridge drives a step up transformer 12V: 420V and a 15nF series capacitor is connected in series with the secondary.
I am using phase shifted PWM to control the duty cycle.
When running at 97% duty cycle the MOSFET temperature reaches 100C at 40A load current. But when running at lower duty cycles, say 20%, then the temperature rises to 100C only at 15A load current.
What can be the reason for more heating at partial duty cycle?
Also, the phase shifted leg runs hotter than the non phase shifted leg. The MOSFET rise time of the other leg is 15ns and the phase shifted leg takes 40ns. The same gate driver is used in both.
Please give suggestions.
Thank you
I am testing a full bridge inverter running at approx 100KHz driven by a 12V source. The bridge drives a step up transformer 12V: 420V and a 15nF series capacitor is connected in series with the secondary.
I am using phase shifted PWM to control the duty cycle.
When running at 97% duty cycle the MOSFET temperature reaches 100C at 40A load current. But when running at lower duty cycles, say 20%, then the temperature rises to 100C only at 15A load current.
What can be the reason for more heating at partial duty cycle?
Also, the phase shifted leg runs hotter than the non phase shifted leg. The MOSFET rise time of the other leg is 15ns and the phase shifted leg takes 40ns. The same gate driver is used in both.
Please give suggestions.
Thank you