Hi

i have finished my power inverter to convert 12 volt dc to 220v ac
i use two stage in inverter DC to DC then DC to AC
i looked over alot of commercial inverter , i confused they use bridge of mosfet maybe 10 or more in DC to DC , and high current IGBT on DC to AC H-bridge
let say 1000w inverter
why they use 5 Mosfet of irf3205 on each side on push pull , while each mosfet can handle 110A , is that ideal for small single mosfet to handle 110A on it's small pins??
5*110A mean 550A it's very high current for 1000w inverter also if we add surge power


In H-brige side they use four fat IGBT - gp4063 , it can handle about 60A , for high voltage ,while 1000w inverter with surge fuse in AC side not exceed 5A

i very confused with mosfet and IGBT current , is this commercial value or true it can handle high current without damage???

 

why they use 5 Mosfet of irf3205 on each side on push pull , while each mosfet can handle 110A , is that ideal for small single mosfet to handle 110A on it's small pins??

They use that number of mosfets to keep the load/watts with in the mosfet "package" limits. If you look at the data sheet it is kind of fooling you. They list maximum values that can't be used together, you can't use both max volts and max amps at the same time. This is because the mosfet "package"(TO-220) is limited to only 75 watts.

They use many mosfets on one side of the inverter also to keep the cost down. IGBTs of the needed size are more expensive than multiple mosfets.

 

Using MOSFETs in parallel also reduces the total ON resistance, reducing the power dissipation and thus the need for large heatsinks, while also improving efficiency.
The maximum current rating is just that. A value you should not exceed. It's not a value you typically use for their operation.

 

They use that number of mosfets to keep the load/watts with in the mosfet "package" limits. If you look at the data sheet it is kind of fooling you. They list maximum values that can't be used together, you can't use both max volts and max amps at the same time. This is because the mosfet "package"(TO-220) is limited to only 75 watts.

They use many mosfets on one side of the inverter also to keep the cost down. IGBTs of the needed size are more expensive than multiple mosfets.

if package"(TO-220) is limited to only 75 watts. what they put this fake values

 

Using MOSFETs in parallel also reduces the total ON resistance, reducing the power dissipation and thus the need for large heatsinks, while also improving efficiency.
The maximum current rating is just that. A value you should not exceed. It's not a value you typically use for their operation.

OK so whats actual maximum operating current?

 

Hello,

This is because the mosfet "package"(TO-220) is limited to only 75 watts.

Why does this page from Vishay show fets with powers of 375 Watts?
https://www.vishay.com/mosfets/to-220-package/

Bertus

 

They are not "fake" values.

Each and every value in the datasheet is legitimate under the conditions specified for the value. It is a matter of understanding how circuits operate, being able to do the required arithmetic and learning to read the datasheet. Someone designing a circuit to switch the current through a xenon discharge tube (e.g. for photoflash) has far different conditions from someone designing a circuit to switch a 20 ampere 100 mH load at 30 volts at 10 millihertz or someone building a 300 kHz switch mode power supply. Conditions that are entirely realistic for one circuit may be completely unrealistic for another. I certainly don't want datasheets that make assumptions about what I'm going to be doing with the part in order to dumb down the datasheet for "typical" applications.

In general, FET datasheets have been improved over the years and it is easier to evaluate a part for an application from the published data without having to resort to calling the manufacturer for unrevealed details.

One thing I will contest in IR datasheets is the assertion that the TO-220 is "universally preferred." Though I've used it in lots of designs, I detest the TO-220. The package itself is cheap, but that is the end of the list of benefits as far as I'm concerned.

 

OK so whats actual maximum operating current?

Typically you want to run no more than about 75% of the maximum rating, assuming you can heat-sink it sufficiently to carry that current.

 

Hello,

To be able to use higher powers, have a look at mosfets in a TO247 package:
http://www.vishay.com/mosfets/to-247-package/

Bertus

 

Hello,

To be able to use higher powers, have a look at mosfets in a TO247 package:
http://www.vishay.com/mosfets/to-247-package/

Bertus

as you say, is TO-220 able to carry 375w of power? is the thickness of pins can carry this high current?

 

Hello,

Read the datasheet of the mosfets.
There you will find the time limits for the current pulses.

Bertus

 

TO-220 able to carry 375w of power? is the thickness of pins can carry this high current?

Your are confusing current with power.
A transistor only need 3A to dissipate 300W @ 100V from collector to emitter.

 

Hello,

To be able to use higher powers, have a look at mosfets in a TO247 package:
http://www.vishay.com/mosfets/to-247-package/

Bertus

That is under the same rules as the TO-220. It just has built in tab insulation. I can ' find the TO-220 specs right now but 75 watts is the limit.

 

Your are confusing current with power.
A transistor only need 3A to dissipate 300W @ 100V from collector to emitter.

Sorry is the mean of dissipation ,lose power? is higher number mean advantage or disadvantage?