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Every power MOSFET has built-in reverse diodes, you don't get them without it. They are not necessarily shown in the symbol. It's a side effect of the transistor geometry that can't be removed on purpose.Does this mean i should use mosfets without internal diodes instead of IRFP 250 ?
Disconnencting primary will be more feasible. Even if you are not charging, it is the same phenmenon when feeding voltages to primary accidently.
A proper rating fast blow fuse can work.
.Another way to achieve this is to connect zenediodes from drain to gate (and see what-if the MOSFET get its driving from anouther source and the gate voltage instead will be driven upwards by force due to these zenerdiodes). The intention here is that when the drain voltage of the MOSFET vill rise dangerously high, then these zenerdiodes start to conduct and will make the MOSFET in question to partly start to conduct. In so doing it will pass current from drain to source of the MOSFET and this leads to the high-voltage spike over the MOSFET:s drain-source to be limited
Mosfet works as the fastest fuse and blow immidetly. I think as PIN mentioned earlier......
Mosfets can withstand over currents many times than its normal ratings for a small duration. Datasheet shows graph between time and maximum (pulse) current. Practically i found fuse to be effective beyond my suspectations. In an instant where sepeate wirings was not possible,a ups without over current safety available at the time was installed and provided a seperate socket for heavy loads. Planned to replace with another in a day or two and told the customer not to connect heavy loads like heaters and irons other than the socket provided.But the next day they connected an iron, found only fuse blown while trouble shooting. Gave a pack of fuses to customer and told him how to replace it and decided to the ups be there. During many months, there were four instances. Fuse always blew when accidently ups was overloaded , customer reported when he came to get another pack of five fuses.Mosfet works as the fastest fuse and blow immidetly
It is due to over voltage and not due to over current that my mosfets blow as discussed earlier.Generally speaking, power MOSFETs can withstand over-current better than one can believe, but over-voltage is an instant killer
Unfortunately, this assumption has neither been proved nor the concurrent explanations seriously checked.It is due to over voltage and not due to over current that my mosfets blow as discussed earlier.
Even if inverter is disabled, current to battery is incresed as voltage of phase is increses. As battery is connected and it clamps to 24v this blows internal diodes as current increses manyfolds
checking battery current in reverse operating a relay lathed, can disconnect primary side from mains imediately.
The diode is simple solution. It can be skipped by this circuit. The sense voltage then be from shunt resister which will be in reverse direction than normal.That's what i mean.
Its behavior is like ac signal. Adding offset to dc will enable sample +/- signal.
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