Naval AC power 1

[ScottI2R]

Hi again all,
After talking with a few co-workers that were in the US Navy, I have learned that on board ship, a whole lot of the equipment used was powered by 400Hz ac. I was wondering why. Can anybody help?

BTW, one guy was an EWO, man, I couldn't believe some of the unclassified "techspecs" and capabilities he told me about! ((Unfortunately, he STILL couldn't answer 75% of the questions I asked (Still Classified!)...Guess I'll try "Janes"..))

Thanks,
Scott

In a hundred years, it isn't going to matter anyway.

 

[TheBlacksmith]

On all the ships I served on the primary power was 60 Hz. All the motors in the engineering plant, ventilation systems, etc. and all the lighting etc. were 60 Hz. There was a small 400 Hz capability, either motor-generator sets or static converters for electronic and aircraft systems.

 

[itsmoked]

Will 400Hz actually waste more power in transmission or just make the system even more "distributed" (shorter wavelength)?

 

[blackwed]

Blacksmith has it right. I've been on or around Naval ships for around 32 years now and ship's service power is 60 Hz. 400 Hz is used for some electronics systems but everyday, run-of-the-mill stuff runs off 60 Hz.

For Itsmoked: Naw, "Naval Power" is that force that grabs me when the wife wears one of those little crop tops and low rise jeans. Still Crazy After All These Years.

DB

 

[jraef]

LOL,
Methinks that power emanates a little lower than the naval!

For Itsmoked re: applying 400Hz to a 50/60Hz motor.
Technically it would try to run that fast, although the shrapnel would likely kill you before you got a chance to measure it. Even if the bearings held up, the motor would have almost zero torque left.


"Venditori de oleum-vipera non vigere excordis populi"

 

[zeusfaber]

Wrong100:

Can you run benefit No. 3 - "WIRING LOSSES ARE LESS (PEAK CURRENTS ARE 16%OF 60 HZ), AND FROM THIS IT TAKES
LESS POWER (LESS LOSSES)." past us again?

To my way of thinking, this would need six or seven times the working voltage, rather than six or seven times the frequency.

A.

 

[itsmoked]

blackwed, Thank you for that clear explanation of naval power.

jraef: All I can say is I wish I had a stiff source of 400Hz to jam into a 60Hz motor.

Especially since my experiments with running induction motors underwater are complete.

 

[BJC]

Once upon a time there were flourscent lighting system sold that ran on 400 cycles ( maby a little more). The ideal was that 420 cycles operating a flourscent lamp gave you the most light for the energy input.
I don't know how they generated the 400 cycles, this was around the 1950s so I guess it was a generator.
Supposedly if your were lighting a large enough area it was economical.
IF I remember one of the aircraft companies in SOCAL had 400 cycle lighting. It was one of those places with hundreds of engineers and draughtsmen in a room that went on and on and on.
Todays Electronic ballast excite lamps at 400 or more Hz.

 

[itsmoked]

Yeah, I think about 10kHz..

 

[wrong100]

WELL THE TIME HAS COME , I MUST HAVE JUMPED
INTO SOMETHING THAT I KNOW NOTHING ABOUT.

ASIDE, FROM DOING THIS FOR 20 YRS,
GO BACK TO ORIGINAL QUESTION AND ANSWERS
1 THROUGH 6. THEY CONFIRM, WHAT I HAVE
SAID. (TWO FROM ITSMOKED)

I CAN SEE MIL SPECS ARE NOT REVELANT
TO A CONVERSATION ABOUT MIL SPECTS.

TRY 1399/? ,HAS ANY ONE DONE REAL EQUIPTMENT
DESIGN TO THIS STD. I HAVE (20YRS).
GOT A FEW THUMBS UP (CITATIONS) FROM THE NAVY.

LOOKS LIKE ITSMOKED SMOKED.

MY OBJECTIVE IS TO SHARE KNOWLEDGE,
IF THIS HAS TO BECOME A CONTEST, THAN 1000S
OF HRS CAN BE SPENT WITH NO BENIFIT.

FOR ZEUSFAFER POWER IS POWER 100 WATTS
IS 100 WATTS.
THE PEAK CURRENT OF A GIVEN CAP RECTIFIER
CIRCUIT IS DEPENDENT UPON THE CAP AND
THE ESR OF THE TRANSFORMER AND CAP CIRCUIT.
FOR A GIVEN VOLTAGE AND LOAD IF I CHARGE A CAP 6
TIMES AS MANY TIMES THAN I WILL (AT 60HZ) I ONLY NEED 1/6 OF
THE CURRENT. FOR THE SAME VOLUME AND CAP AND ESR'S
400 HZ HAS 1/6 THE PEAK CURRENT IN THE TRANSFORMER
AND CAP.
MY CALCULATOR'S MUMBERS ARE 60/400 =.15.
O WELL 1/6 SOUNDS GOOD.
AT ANY RATE YOU CAN HAVE 6.6 (1/60/400) MORE WIRE,
IN THE TRANSFORMER (.15 ESR, (RESISTANCE))
WITH THE SAME PEAK CURRENTS IN THE CAP WHICH EQUALS TO
1/6.6 LOSSES IN THE TRANSFORMER.

DID I PASS YOUR TESTS, IF YOU MUST TEST ME
THAN DO IT. DO NOT GIVE ME A BUNCH OF GARBAGE.

WITH MIN 50 PS BASED ON THIS,
TIMES ABOUT 500 UNITS, TIMES AVG 1O YRS,
MY RAILURE RATE IS 50*500*(10*1 HR PER DAY =
91 MILLION HOURS. IF YOU EXTEND IT
TO 24 HRS PER DAY IT GETS BAD ONLY ABOUT
2 BILION.

NOT BAD. EVERY ONE
ELSE IS 10 TO 1,000,000 TIMES BELOW THIS
IN REAL NUMBERS.
HAVING PUT STUFF UNDER WATER, ON THE WATER,
IN THE AIR, IN SPACE, AND 5 MILE UNDER GROUMD.

ITSMOKED

DID I PASS.
OUT OF 400 + DESIGNS IN THE LAST 20 YRS
I HAVE HAD FINAL SAY ON ALL BUT ABOUT 50.
AMD I WILL CONSIDER THE FIRST 20YRS.

CAN YOU PASS.

I THOUGHT THIS WAS ABOUT INF.
NOT JUMP ON THE NEWBI.

hope NO ONE meets one of my designs.
there was a few of them on tv in the gulf war.
WH0 ARE YOU, WELL IT IS LATE AND I MUST
INTERVIEV A NEW ENG TOMORROW (TODAY).

"every time i go into a design i ask
if it failes, how many will die, will i be dead,
will it make us slaves,
how can i make it serve
what was intended"

A SORD IS A TOOL, GUTTING PEOPLE, CUTTING
GRAIN, IT IS STILL A TOOL

"LIVING IS EASY" FROM "PORGY AND BESS"
YES I READ IT AND SAW THE MOVIE.

BY THE WAY 100 IN MY HANDLE STANDS FOR 100%
WRONG THE FIRST TIME 100% RIGHT IN THE END.
WRONG ONLY MEANS THE CONCEPT WAS WRONG AS I SAW IT,
RIGHT ONLY MEANS THE CONCEPT WAS CORRECT AS I SAW IT.
PEOPLE DO NOT KNOW HOW TO THINK ANYMORE,
THEY TAKE WHAT IS FEED AND DO NOT UNDERSTAND
THAT EVERY ACCEPTED CONCEPT EFFECTS ALL OTHERS,
AND MODIFIES THE OVERALL PERCEPTION OF THE WORLD
THAT THEY LIVE IN.
PUT AN INCORRECT LINE INTO A PROGRAM
AND IT MAY GIVE YOU THE CORRECT ANSWERS UNDER GIVEN CONDITIONS, BUT WHEN IT IS USED WITHOUT LIMITS
THE FLAW WILL SHOW UP.

 

[itsmoked]

Yeah, I think you passed all right.
I think your caps lock is pressed too.

 

[BJC]

WRONG100
It's a "sword" not sord. Are we down to 99.44 % ?

 

[wrong100]

SORRY I DID NOT REALIZE HOW TIRED I WAS.
AND WHAT I WAS WRITING, I HAD STOPPED WORKING (GETTING TOO TIRED).
AND THEN TRIED ANSWERING THE GUESTIONS.
NOT MY NORMAL SELF, (OUT OF IT).

A FEW FACTS, RUNNING 400HZ MOTORS ON 60HZ THEY BURN,
(TOO MUCH CURRENT). RUNNING 60HZ MOTORS ON 400HZ THEY SIT, (NOT ENOUGHT CURRENT).

BACK TO THE TRANSFORMER, ROUND NUMBERS FROM MY COMPUTER,
(BOTH USING M6 MATERIAL),
FOR 60HZ 100WATTS 1:1 (11.2WATTS AT 3.2LB).
FOR 400HZ (12.2WATTS AT .97LB), WITH THE SAME
VOLTAGE LEVEL.

MIL SPEC 1399 CALLS THREE TYPES OF PRIMARY POWER.
ONE FOR GENERAL USE, ONE FOR HEAVY STUFF, AND ONE FOR
SPECIAL AND AIRCRAFT. THE AIRCRAFT IS 400 HZ.

AGAIN, VERY SORRY FOR BEING SUCH AN ASS.
AFTER READING WHAT I DID, I CANNOT SAY HOW SORRY,
AND HUMBLE I AM. PLEASE ACCEPT MY APOLOGY TO ALL.
I HAVE A HARD TIME RELATING TO THE JUNK THAT I DID
BEFORE, BUT I DID IT.

WRONG100

 

[itsmoked]

Hahaha, Not a problem. Thanks for the comeback.

 

[Skogsgurra]

Tired. OK. But release that caps lock. Please.

 

[zeusfaber]

I still miss the ability to delete some of the things I've written here without tearing down the whole thread at the same time.

Going back to the "peak current" bit (don't like to let a learning opportunity pass by) - is this the surge of current that goes to top up a smoothing capacitor once every half (sixth of a, for 3 Ph) cycle if you're pulling dc off your system?

That would explain the difference of opinion - I had been thinking in terms of an ac load.

A.

 

[wrong100]

I think you will understand the problem better,
if I generate a small table.

60hz 400hz values
1.125 .75 core size needed in inches
441 150 turns needed for gauss
4.6 .91 avg resistance of wire
98 96 precent of use of bobbin area
3.245 .973 total weight (includes wire)
9.250 1.9 wire loss watts
2.016 10.3 watts loss in the mag. material
14.1k 13.9k gauss

The only items I spec were fc (60/400),
voltage (115), current (1A), and after the computer
pick was made, I had to change the number of turns to get
the flux denisity about the same.
This material should be run at about 12k gauss at
this woltage level. Mil spec ,I would try to do
10k or 11k to be able to go 30% higher in voltage.
This is for EI cores with a sguare stack,
(center leg .75 wide times .75 high).

Geting back to real designs, I would not
use either of these basic designes. too much
loss (temp rise, and too near the Bsat limit).

To answer the statement I made about
peak current losses, from the table you can
see that there is about a 4 to 1 ratio
in resistance (for the winding (copper loss))
which means a 4 to 1 ratio in
watts loss for the winding. This applies to rms as well
as pk currents.

I need to inject this, it may not flow
but it is revelant nowdays ( always with mil spec).
In a ps that converts ac to dc, there is a
concept called "power factor".
the best expresion is "real power/ apparent power".
For simple terms, a current conduction of 60% is
"NOT" a power factor of .6 (60%) in
a single phase system.

Some other losses get into the mix
as the currents and or HZ get larger.
If you are doing, a power loss (efficency), or
a temp related design, the "normal" design,
is to make wire losses equal mag losses.
The only way I can address this is to say
that it is in general correct for low fc designs.
As you can start to see, even a "simple"
60Hz or 400Hz transformer starts to get complex.

Once upon a time there were courses
you could take to understand "analog"
design. I have had sr. (20 yrs) design
know how, not understand the basic problems,
in a transformer, and power supply design.
As far as I know, less than ten schools teach ps,
and say only 4, have a complete spectrum.
Example (newbi from school) no concept of
how to cal a caps energy in a given system.
No general concept of temp rise in a component.
I used him to do "mean time between failure"
reports which forced him to learn the above
concepts and much more. That assignment
coupled with my guidence and other eng help
enabled hin to understand the real math side.
When he was ready we next started him doing
pc card layouts and making it work.
(You canot do 20amps with a 6 inch loop at 10ns.)
The only real problem he has remaining is magnetics.
I have been trying to teach him, it will happen soon.
He understands the magnetics it just will not fall
into place (click). Once this happens he needs
to unify all of this into a overall understanding.
Once he gets there he will be able to do any design.
Note: he should surpass me and all the designers
that I know, some are considered the best
in the U. S. Than he needs to update his technology.
We are about ten yrs behine.
When he gets there I hope he stays with us.
This has been a 4 yr teaching.
As eng mag I can only do job assignments and
show how they should be done.
As a person I try to connect with him and understand his problems, and also show him all of the aspects of
coping with companies such as BO and RA.
At this stage of my life "62" sharing knowledge
(while it has always been a large part of it)
has taken on a different aspect, (this is my third
teaching, and must be my last).

I debated to myself about putting this last
segment in, but after readin the context
I decited that I should. It is a flow that just
came out, and I think gives the reason we are
all here. We all want to share "know how".

Personal note, I do thank you for your
understanding, and again sorry for the
stupid reaction.

 

[jraef]

I, for one, feel as though I recieved a valuable lesson in 400Hz theory and application today. I'll probably never use it, but the next time someone asks me why, I'll have better answers. Thanks to all.

And thanks for releasing your Caps-Lock key Wrong100. If you're like me, I struggle with my "advanced hunt-and-peck" typing skills, so I tend to use either all caps or no caps in emails rather that have to keep going back to fix things. But posting in this forum has forced me to develop better skills because I too found that people don't like it and tend to marginalize those that do it.

"Venditori de oleum-vipera non vigere excordis populi"

 

[IRstuff]

No problem, although, you don't need to manually insert carriage returns, either. The HTML display handles that pretty well. In fact, your postings have almost all wound up looking like they were formatted for a newspaper display, whereas, on most people's browsers, the display window is actually double or triple what you formatted.

PS. thanks for the info..

TTFN

 

[ScottI2R]

WOW!
What did I start here everyone? I cannot believe the overwhelming response (in quantity and especially QUALITY) to the question I posted. I cannot thank you all enough. I HAVE been "learned" you might say. This is without a doubt, the most valubke forum I have ever joined. I hope that in the future I will be able to contribute something worthy to someone else just as everybody here has to me.
Thanks again all,
Scott

In a hundred years, it isn't going to matter anyway.

 

[RalphChristie]

Good to see some old-timers participating in the forum, bad that a lot of their information/knowledge is going out of the trade after their retirement.

Thx for the info wrong100