one side of IR2110 full bridge mosfets burns instantly

[farid72j]

I have build a full bridge inverter using 2 IR2110 and 4 irf840 or 20n60 mosfets. pwm frequency of high side is 18 kHz and for the low side i use 50 Hz pulse. the circuit works fine with 25 and 50 volt from dc supply.
the problem is when i connect 310 v dc of rectifying 220 v ac to the circuit, 2 mosfet on one side burns instantly.

i use different mosfets and dead time up to 2 ms, the result is the same.
can someone tell me where is the problem?
thank you in advance.

 

[farid72j]

My idea:
if - by accident - P1 and/or P2 is not connected then the signals may float (check this). If floating, then you may have situations where it may cause overcurrent - or any unknown behaviour.
Thus I´d pull down them here on this board. It´s more fail safe.


Yes. But these are fast, low capacitance values. They are correct here.
I asked about bulk (= high capacitance) capacitors. (read posts before)


You still think in DC and thus about GND to be "low ohmic".
But you need to learn to think in "high frequency" and thus "low impedance". (read posts before)

--> you really need a solid GND plane for the (high speed / high rise and fall rate) signals on the exact opposite side of the PCB.
Currently you just have a uselessly big area of GND. All the big GND area does not make any signal "low impedance".


UF4007 are not suitable. Installing them is a waste of money, they don´t bring any benefit. (read posts before)

Klaus

good idea, i will pull them down on this board.
if by bulk cap you mean an electrolyte one after rectifier, certainly i have that and its on another board.
i will try GND plane.
also i have purchased some byd26e diodes. those would be good?

 

[KlausST]

byd26e

I can´t find a datasheet. Please post a link.

Klaus

 

[farid72j]

I can´t find a datasheet. Please post a link.

Klaus

sorry i meant byv26

 

[KlausST]

Hi,

the BYV26 forward voltage @ 1A is 2.5V max.
the MOSFET dioe forward voltage @ 8A is 2.0V max.

But the idea of an external diode is to have less forward voltage. The external diode should prevent the MOSFET internal diode to become conductive.

Something like STPSC10H065DI is much more suitable. (But I didn´t spend much time for a search).
There are MOSFETS with fast internal diode.

Klaus

 

[danadakk]

https://www.infineon.com/dgdl/Infineon-Managing_Transients_in_Control_IC_Driven_Power_Stages-AN-v01_00-EN.pdf?fileId=5546d46259d9a4bf015a4615e1280121

https://www.infineon.com/dgdl/Infineon-Using_Monolithic_Voltage_Gate_Drivers-AN-v01_00-EN.pdf?fileId=5546d462584d1d4a01585242c11947b1

Regards, Dana.

 

[Easy peasy]

STTH15L06D

is a good parallel diode choice too, if you need an anti-parallel diode

another well used option is to slow the switching ( turn on ) and make sure the heat-sinking is good.

 

[farid72j]

Hi,
finally it works.
i read the application note thoroughly (bypass cap >>10*bootstrap and put close to IR2110) and used your suggestions.
finally printed this pcb and it worked.
just wanted to thank you all for your suggestions and putting me in the right path.

 

[Easy peasy]

Well done, we all look forward to seeing waveforms of the operating converter

 

[farid72j]

Well done, we all look forward to seeing waveforms of the operating converter

Sure thing. Currently i'm working on output filter for 50hz and less frequency. After that i will post output signals.