My "perky\cat/volvo" DC bat charger

[Lloyd]

Bob,

And others interested in lundell alts this link http://www.tpub.com/content/armyordnance/OD1003/OD10030027.htm is the military education on the basics of a lundell brushless induction alt.

[Lloyd]

it might be to early to start adding a load dump to my little co-gen project.

but it's not to early to at least think about it.

this looks like a viable option http://www.chromalox.com/catalog/resources/C%20overview.pdf my original plan was to add a 12 volt immersion heater to my system, as a way to keep the gen loaded, once the bulk state of charge was reached.

now i am starting to think that I can use a 3 phase load dump, by pass the trans/rec..which would take a load off the diodes.

as a matter of fact, I'm thinking that a proper 3 phase heater might make more sense, than adding a  separate diesel fired boiler to my system...the boiler burns about 2.5 liters per hr for 50k btu, which is about 10-15k btu larger than I need at full run 20 f outside temp.

my little perky\cat/volvo burns about 1 litter per hr at it's peak load efficiency, by capturing the waste heat, and adding a 3 phase boiler sized to the out put of my alt...I think I can produce all the heat I need, and keep the perky-cat running at peak...that's less fuel than the d-boiler...and capital investment to a d-boiler is about 2.5K...which is about twice what I can buy the 3 phase boiler.

Lloyd

[mobile_bob]

as odd as it may seem i am seriously considering the addition of electric baseboard heaters for just that purpose

there will be times in the winter that i can use the additional load to reduce warmup time, to fill in between load cycles
and when the heat would be useful in the house.

baseboard heaters are relatively cheap, take up little space and do a remarkable job at warming up a room fairly quickly
and fill in the gaps nicely when needed.

bob g

[Lloyd]

Hi Bob.

Baseboards are an excellent source of heat..maybe not the most efficient..but done right..I think they are sound.

By the way the cable price is $8.20 a foot my price...a few a bucks a foot more than I pay for type 3 tinned marine 4/0 cable...the beauty is, instead of 4 4/0 cables running 35 feet X 4 = 140 feet, I will be running jet starter cable 35 feet, saving 3 times the price in cable, or $525.00 usd, that should go most of the way for the trans/rec.

Bob, and Group

In my conceptualization of my co-gen...primary it's a bat charger through bulk state. The co-gen side is when there is a heat demand above and beyond the heat recovery during bulk charge.

So I had idealized that the I would have a 12 volt(dump load) immersion heater/s in my secondary heat storage tank.


Then I had the bright idea of switching to a 3-phase immersion heater linked above. My concept was, once bulk state was reached, the system would dump to the the 3-phase domestic boiler.

After sleeping on it for a day or 2....I had an epiphany(usually those are good things and have helped me solve many a problem)....

Once bulk state is achieved, by design the field current is cut to reduce output of the alt...that's good for bat banks...but not so good for my efficiency of the overall system....and the 3-phase immersion heater will be only anemic at best...the engine won't be running at it's most efficient, bc of the the light load.

Now I can add a switch to divert the full power away from the bat, to the heater, but I won't be able to continue into absorption/float. The more I thought about this, I realized it would effect the 12 volt dump load same as the 3-phase dump load.

So now it looks like control to reach maximum efficiency as a co-gen is going to require more...it may be simply adding a second balmar controller to run from a switch during dump load, or a silicon switching system to use a single controller.

Or it may require a SMR switch mode rectifier, with an addition of an exciter/field regulation circuit to allow the alt to power a 3-phase buss...and let the SMR control the charge cycle to the bat, irrespective  of the alt 3-phase output buss voltage after bulk charge???


I think I'll have to sleep on this a few more days...I will awaken periodically to check this forum...in the event someone else has thought about this and has resolved the issue.

Lundell...the good, bad, and ugly...but still possible the best bat charger.


Anyone have any thoughts or epiphanies...please post.


Lloyd

[mobile_bob]

here is what i would look into if i were you

you ideally would want to switch the 3phase from the transfomer rectifier assy to a heater/dump load

for that i would use a reversing contactor, maybe a size 2 would be adequate
they are designed for reversing 3 phase motors, but there is no reason why one cannot back feed the three phase supply
into the lower output terminals (motor) and take the power off of the two inputs (after removing the jumpers used for motor reversing)
and use one of the inputs which is now an output to go to the trans/rect unit and the other input (which is now an output) to go to the dump load.

this would allow for an isolated control that is electrically and mechanically interlocked, the reversing contactors can be found on ebay quite reasonably
if you watch for them.

that leaves how to control the reversing contactor, you can do it manually with a toggle switch or one could use a small current relay that has its coil in series with the field wire to the alternator, by careful adjustment the current relay could provide a logic drive to initiate a switch over when the field current dropped to a designed low limit.

there might also be a post on the balmar that goes hot or grounds when the controller goes to float? i can't remember for sure on that one. if so
it could be used as a logic drive to control the reversing contactor via a buffer circuit of some sort, either transistor or relay.

then there is this possibility if you are good with electronics

you could use a thermocouple such as an ispro exhaust pyro prob, use its output power which is fairly linear and bases on load
when it gets to a low exhaust temp it can tell the electronic box which in turn can provide the logic drive control of the reversing contactor.

that same unit could have a high setpoint also, so that if the engine went into overload the exhaust temp goes over a certain level
and another logic drive could then close and start to drop loads, such as tripping the 50% post on the balmar.

all sorts of things can be done i suppose.

bob g

[Lloyd]

Hi Bob,

Those are good ideas, my original thought, was to use a Krauss-Naimer rotory switch, for simple manual control, or a motor contactor as you suggested, with potted voltage switches and relays, for a more automated process.

But...Then I started thinking about the out put of the alt. As the bats reach absorption voltage the Balmar reduces field current, which of course reduces out put of the alt...so that in turn would reduce the volt/amps going to the 3-phase load dump, ultimately unloading the load on the perky\cat/volvo. 

So I also have to switch the field, and add in a fixed voltage control so the the alt continues to maintain field voltage of the alt at high output. That means I need to disconnect from the trans/rec bc the bats would continue at the higher field voltage basically turning the bats into heaters until they failed...bc I have bypassed the Balmar control of the bat voltage.

It might take an SMR likely used on the bat charge side of an inverter..to accomplish my goal of having the perky\cat/volvo running at it's peak efficiency.

In short how do I keep the alt in HO, while not overcharging the bats, and dump the excess volt/amps to HW.

Lloyd

[mobile_bob]

i guess i haven't given your specific problem as much thought as it will likely require, because
i have dual alternators, also an st head and a sanden compressor to switch in and out in different combinations
to maintain full load operation on the prime mover.

one option might be to first measure how much power the engine will have to deliver when the batteries go to low
charge requirement (float), at that point switch in specific amounts of load onto the inverter AC output. that should be quite easy to so
as there are various rated heating elements available, and the use of maybe a 500, 750 and a 1000 watt element would allow for 3 steps individually
or 7 steps by using various combinations all the way up to 2250watts which is about 2500 watts mechanical load.

the charge system should support that and the low charge requirement of the batteries after bulk and absorption without dropping the buss voltage sufficiently enough to kick the balmar back into higher current, and if it did the batteries would only take what they need of the power available the balance would go directly to the inverter to power the load.

it might be a simpler approach to explore,

earlier i mentioned the use of baseboard heaters in my application
i could see them being used in the winter months as the unit starts an hour before wake up, when presumably the house would have
cooled down over night,  the baseboards would provide a dump load to assure full loading of the trigen and provide rapid heating of the house.

same would go for an hour before supper, when i might have been gone during the day and the home cooled down by design, having the ability to quickly reheat the space would be useful at that time also.

perhaps something like that would work for you application as well?

bob g

[Lloyd]

Unified Constant-Frequency Integration Control of
Three-Phase Standard Bridge Boost Rectifiers
With Power-Factor Correction

http://www.dianyuan.com/bbs/u/52/1176560502.pdf

or this

Design And Implementation Of A 6k W Three Phase Buck Pfc Rectifier

http://www.slideshare.net/asijoe/design-and-implementation-of-a-6k-w-three-phase-buck-pfc-rectifier-2687816

http://powerelectronics.com/power_systems/

[Lloyd]

Bob...

This is a neat flavor it would be ideal in a 48 volt sys

http://www.mip-inc.com/rectifiers.htm

http://www.mip-inc.com/rectifiers_specs.htm

[Lloyd]

http://www.time-mark.com/ProductDetail.aspx?id=14&cp=0&ps=2&App=1

Hot Features:

   * Detects phase loss, phase reversal and low voltage

   * 400Hz and gold contact options

   * Automatic or manual reset

   * UL Recognized and CSA Certified


The Model 263 continuously monitors 3-phase power systems for phase loss, low voltage and phase reversal. The monitor consists of a solid-state sensing circuit, driving an electromechanical relay.

Applying correct voltage and phase rotation energizes the relay. When properly adjusted, a fault condition will cause the relay to de-energize, even when regenerated voltage is present.

When the fault is corrected, the Model 263 automatically resets. A manual reset version and an option for gold-plated contacts are also available.

The Model 263 does not require a neutral connection, and can be used on Wye or Delta systems. Each of the five different voltage ranges is adjustable to allow the monitor to be set for existing conditions. NORMAL and TRIP LED indicators are provided to aid in adjustment and system troubleshooting.



Hot Features:

   * Allows up to 6 loads to turn on sequentially

   * Adjustable 3 to 6 second time delay

   * 24 VAC and 120 VAC models

   * 2500 VRMS for 10 ms°

The 352 Load Sequencer is designed to allow up to six loads to turn on sequentially. Sequencing can be initiated with an external switch for sequence on-sequence off (first-on-first-off) operation, or directly with the application of power for sequence on/all off operation. More than six loads can be sequenced by coupling together two or more 352 Load Sequencers.

In industrial applications the 352 is idea for starting a number of motors, pumps, fans, etc., when it is not desirable for all to be turned on at once. As an energy management device, it can help to hold down high demand charges by spreading the start up of energy consuming loads over a period of time. Used in conjunction with time clock and temperature limiter, the 352 can readily provide night setback sequence control of HVAC equipment.


ot Features:

    * Monitors over and/or under frequency

    * Automatic reset

    * Solid-state electronic circuitry

    * Operating Frequency 45-1023 Hz


the Model 2922 Frequency Monitor is designed to monitor power line frequency. It is intended for systems where line frequency variations will cause improper operation of electrical equipment.

A solid-state sensing circuit drives two internal electromechanical relays. One relay is energized when the line frequency is high and the other relay is energized when the line frequency is low. Operating power is drawn from the same line being monitored.

The Model 2922 is set to the over and/or under frequency trip points using ten binary-coded switches. A frequency variation outside the trip points causes the appropriate relay to energize and an appropriate LED indicator to illuminate.

Applications for the Model 2922 include standby power plants, portable power supplies, and windmill generators.

[Lloyd]

http://www.m-system.co.jp/mssenglish/PDF/ES/53/es53u.pdf

Model 53U Power Monitor
• Measures over 500 variables; 1800 combinations of AC Power parameters
• Single type module is usable for all of single-phase/2-wire and 3-wire, three-phase/3-wire and 4-wire systems.
• All measured variables can be transmitted to the host PC via RS-485/Modbus RTU.
• Energy count pulse or limit alarm output selectable. Pulse rate can be specified. Simulated output is also possible.
• Programming lock to prevent unwanted configuration changes
• Input range up to 480 Vac, 1 A or 5 A

[mobile_bob]

looks like there are lots of very interesting gadgets that might be quite useful for our purposes

thanks for the links, later when i get to feeling a bit better i guess i got some reading to do.

bob g

ps. how are the transformers coming?

[Lloyd]

Bob,

I think I have sympathy pain..I am barely mobile..it takes everything I can muster to amble, sit, stand or laydown.

Back in 87 I was hit broadside in the passenger door, by a 2 ton flatbed loaded to the top of the racks with concrete forms.

It ruptured 1 disk in my low back and 1 in my neck, both into the spinal canal. I had a stepfy-plate fusion on my L4-L5.








I never could bring myself to the 2nd surgery.

For the most part, I get along pretty well, since the surgery. Afterward, I would have about 2 episodes a year, usually caused by doing something stupid...like trying to  live a normal life...Now it seems my episodes are coming about 4 times a year. It takes about a week to get past the pain, and another 2 weeks to get back to something normal.

Currently, it feels like someone took 2 coke bottles, stuffed em in a burlap sack, beat em profusely with a hammer, then made an incision about 4 inches above my belt, and with a funnel pored all that glass in..then super glued it shut.

Now back to topic...I hope everyone finds something useful in the links I post..even if it just spurs another thought.

I tend to link to my topic... hoping crowd source will help me find the path, it also helps me keep my thoughts organized.

I think there are a lot of off the shelf answers to many of our system needs...I would love to able to say O, I need this or that, and sit there and weld/solder it up..write the code. But I'm not a welder, or an EE, so my first solution is to search and see if someone else has already solved the same problem.

I have used time-mark over/under voltage switches, and their current switches many times, they are a great product..so the were they first place I looked for my 3-phase needs.

thanks for all your help.

should have a transformer/rec..by the end of next week.

lloyd


Not until you have been in the deepest valley
do you know how magnificent it is
to be on the highest mountain.

[billswan]

Lloyd and Bob and other back pain suffers

Years ago when I was a teenager I did a lot of STUPID stuff with my body. Mostly over lifting by trying to make money after school by scraping out old cars.  Also stuff like circle track auto racing accidents. So although none of the incidents were as bad as what lloyd described I KNOW back and neck pain INTIMATELY.

The most relief that I have ever had came after I started taking MASSIVE doses of vitamins and minerals, they seem to be the building blocks of life and your body will repair itself if it has the "PARTS" that is the vitamins and minerals.

I know it may sound stupid of me but I personally take about $250 of high quality high priced vitamins and minerals per month and that is saying something, as I am quite close with my money. Read that as tight ass!

Also I have learned to stay away from certain foods like soda pop and coffee and carbs. Soda pop like coke is like poison to bones............

Wishing you back and neck pain suffers relief I know you need it!!!!!!!

Billswan

[mobile_bob]

Lloyd and Bill

i appreciate the thought and advice

my back issues are not from injury but from genetic defect, having been diagnosed with scoliosis at age 13 and then
spending 5 years in what is lovingly called the "iron maiden" (milwakee back brace) which is quite a medieval and torturous
piece of hardware, they were able to stabilize my spine, however

what they were less than upfront with me about was the fact that most who endure that treatment end up with arthritis
later in life usually starting in middle age, and there is also other issues that have a high probability of causing chronic pain
all along.

that pain has always been a part of my life since about 13 years old, but it was something that i could manage quite well
when i was younger with stretching, being careful what i did, heat and rest. As i got into my mid to late 40's those remedies
became less and less effective and the pain became much more pronounced and frequent.

now at nearly 54 i can count on one hand the number of days in the last 10 years that i have been pain free without
either spinal injections or meds.

those days that i wake without pain are days that i just want to be at peace with god and nature, and not to anything to set it off again.

having been to in the last few years several spinal specialists, and surgeons the consensus is the same, my issue is inoperable because of
the high likelihood of a poor outcome, basically they would have to split me from the base of my skull to my tailbone, front and rear
and completely rebuild my spine using two main stainless steel rods, many screws, and several feet of stainless tie wire. there would then be
6 months of a body cast, followed by 6 months of PT to relearn how to walk, and the risk of infection or paralysis is higher than the surgeons
or I find acceptable.

even if successful the arthritis will remain and it is a significant portion of my pain most days.

we all got our cross to bear i suppose, and i realize i have it pretty good compared to others, things can always be much worse.

anyway, thanks guys

bob g