well i am designing a booster circuit that takes at the input between 70 to 120 volts and its giving me at the output a value of 350 volts which should be steady.
The idea is that i have an inductor of value 1mh and a capacitor of value 20uf , the igbt is instantly blowing up and i dont know why .
Any ideas or help about why would the igbt blow instantly?
Hi Ali,
Would you specify under what conditions the IGBT blows up? Is it during the normal operation condition (like the converter is working and then after a while the switch blows up) or does it blow up right after starting the converter?
If it's right at the starting time, have you tried soft start in order to manage the inrush current into the switch?
In this case, it is highly possible that the switch blows up due to the inrush current at the starting time.
You can either gradually increase the input voltage from zero to the nominal voltage or gradually adjust the duty cycle from zero to the required value (if you are using a boost controller chip, it should have the soft start capability. Check out its datasheet for the soft start capability. Usually a pin is dedicated for adjusting the soft starting of the converter. It gradually increases the duty cycle from zero to the nominal value at the starting time. Usually a capacitor is placed at this pin to adjust the soft start time. But if you are using a DSP to control the converter, you should implement it yourself in your code.)
Hope that helps!
Dear Ali,
Can you provide the diagram of the actual circuit you built including the gate driver?
Hello Ali,
there might be a lot of reasons the IGBT blows up at startup, especially if you just start with a fixed duty cycle, as Ali Shahabi already suggested. Other things to look at would be the construction of you inductor (saturation issues), the gate drive circuit (as Michalis Florides suggested), the actual PCB Layout, the switching frequency and the rectifier diode.
To help you further, the circuit diagram with part names, some pictures of the actual setup and a detailed description of the Inductor would be necessary.
Best Regards,
Tobias
Dear Ali Srour,
welcome,
The switching transistor could be burnt if it conducts continuously. This happens when you make the duty ratio is equal to one. So, you have to avoid this operating mode by limiting the duty ratio smaller than one.
Best wishes
Please read the book
Principles of Power electronics
by
Kassakian
from
MIT
in
Boston, MA
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