Re: BIG solid state devices...

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Terry Fritz" <twftesla-at-qwest-dot-net>

Hi Sean,

Your absolutly right!  I was thinking the effecency of 97% seemed low when
I wrote that ;-))  See my other post today too.  The IGBTs should run stone
cold...  Very little power should be lost in an IGBT gap.

Cheers,

	Terry

At 10:52 AM 7/13/2002 -0700, you wrote:
>> Hi,
>>
>> I note the Hitachi MBN1200D33C
>>
>> http://www.hitachi.co.jp/Div/ise/pdevice/igbt/index-e.htm
>>
>> http://www.hitachi.co.jp/Div/ise/pdevice/igbt/d-igbt/1200d33c.pdf
>>
>> switches 3300 volts at 1500 amps with 6 volts of CE drop...  If one were
>to
>> put 8 in series to run a 21kV firing voltage, you would get about 48 volts
>> drop or 48 x 21000 = 1008000 watts (i) of instantaneous power loss.  But
>> the system power is 1500 x 21000 = 31500000 watts (i)
>
>I'm confused . . . Why did you multiply the voltage drop by the firing
>voltage?  Power lost should be 48 x 1500, so 72000 watts, while the total
>power is 31500000 watts, so about 99.8 % efficient.
>
>Sean
>