Witte Diesel Electric Hybrid

[Diesel Guy]

I'm putting the finishing touches on my Witte power plant. I just wanted to give an update on my project.

I just purchased a 20 KW Permanent Magnet alternator for it.

http://cgi.ebay.com/20KW-Rare-Earth-Permanent-Magnet-Generator-/160464573436?pt=BI_Generators


I purchased such a large alternator head and I will only be using a small fraction of the capability. It has a massive 48 mm shaft and will operate many hours without maintenance. It seems fitting to install such a heavy duty electrical system (340 lbs.) on back of the Witte, which is built like a tank.

I will be running my dual pulley ratio and flywheel weight on the alternator. It adds about 128 lbs. of flywheel mass and spins at 1,800 RPM. The engine speed at the set pulley ratios are, 620 RPM from the 11.1" and 438 RPM from the 7.8".  Belt chirping will not be an issue due to the massive flywheels on the Witte to control the power strokes and I will not be running peak capability of the engine (which is the cause of the pulsing). Therefore, I will have clean AC output.

I am installing two heavy duty Military 28 volt alternators with Electromagnetic Pulse Protection devises installed. I will have multiple ways to operates my power plant due to having two pulley ratios and dual alternators.

These are the exact alternators I have and mine are brand new as well:

http://cgi.ebay.com/ebaymotors/HUMVEE-100-AMP-ALTERNATOR-28-VOLT-P-N-10947517-1-_W0QQcmdZViewItemQQhashZitem1c0e78fb91QQitemZ120501894033QQptZMotorsQ5fCarQ5fTruckQ5fPartsQ5fAccessories


First: I could operate it on the 20 KW Permanent Magnet alternator alone and put out 4,800 clean AC watts with minimum light flicker.

Second: I could operate it on high output  "Hybrid Mode" . Which is run the 20 KW Permanent Magnet alternator set at 3,600 watts and will be set to operate the 28 volt alternator at 40 amps, very conservative to keep cool , maximum durability.

Third: I could operate it on the 20 KW Permanent Magnet alternator alone at 438 RPM and put out 2,400 clean AC watts with minimum light flicker.

Fourth: My favorite setting, I could operate it on low output   24 - 7 - 365 "Hybrid Mode" . Which is run the 20 KW Permanent Magnet alternator set at 1,200 watts for selected electrical systems and will be set to operate the 28 volt alternator at 30 amps, very conservative to keep cool , maximum durability needed. 2.4 HP required to drive the AC system and 2.4 HP required to drive the DC system. 4.8 HP required. The Witte will produce about 6.5 HP (conservative) which would equate to 75% load at maximum AC and DC loads and 37% at just DC loads.

I have a large 1,000 amp/hr. Surrete battery bank and two operational Industrial 3,600 watt continuous and 12,000 watt peak,  inverters with two back up inverters on standby. A battery bank does not like to be charged continuously, but I am putting in such a small amount of amps, like a water wheel that my battery bank still cycles but the cycles are much shallower due to the continuous input of small amperage , 3% of the total battery capacity.

On the low output   24 - 7 - 365 "Hybrid Mode" I would have 8,400 watt AC continuous (within reason) and peak 25,000 watts (never reached) power available from an engine lopping at 438 RPM.

I also have written in the past, I installed my custom oil filtration and  oil replenishing system so the engine can go unintended if needed for 3 months at a time 24 - 7 - 365 without a single shutdown. Shut down requirement is 4 times a year.

This plan is the reasoning behind me choosing the Witte, there is not another engine that can replicate it in fuel consumption/durability/required Hp/lack of maintenance, as my set criteria and is a perfect (in my book) prime mover and this is the outcome. When finished I will send a video from you tube.

Diesel Guy

[LowGear]

Hi Diesel Guy,

That's a lot of generator.

Does anyone know of a book like "Electrical Generation For The Complete Idiot" I might read.

Casey

[Diesel Guy]

Lowgear,

"Does anyone know of a book like "Electrical Generation For The Complete Idiot" I might read."

You don't sound like a dummy to me by any means, your just a person looking for more and more  information (like the rest of us) and that is what this and other forums do best.

Lowgear, I know you own a Witte. You mention generator knowledge, the reasoning behind me using my Witte/inverter hybrid configuration is that the engine can operate an almost constant low load condition keeping the battery charged and the AC from the permanent magnet alternator will power my heating loads. I don't like running heating loads on the battery bank.

First I chose a permanent magnet alternator, I don't want to play with my generator, once set, set it and forget it. The output voltage is proportional to the shaft speed. The more steady the input speed the more consistent the voltage and frequency regulation will be. I wanted the largest bearings possible on my alternator, so that is why I oversized this much. There would be minimum side loading from the belt to apply the proper amount of belt tension to avoid belt chirp.

Belt chirping is because the flywheels are too light/small or pump timing is to advanced or the pulleys are spaced close together or heavily overloaded. I am using a 138" serpentine belt so to provide the greatest distance between pulleys and enable a "cushioning" action (slight stretch) allowing the belt to maintain traction on the pulley and not chirp with reduced belt tension.

To maintain regulation at low engine speeds requires an acceptable amount of torque. The more over squared the engine is, the greater the torque capability at the cost of lower  HP capability. A high torque engine resist speed variations better than a low torque engine per equal load input.


This is where the Witte shines. It is a true old style "over squared" engine design with a 5" bore and 8" stroke.  It has a .625 Bore/Stroke ratio. My 14/1 Listeroid is only slightly over squared and has a 5.12" bore and a 5.76" stroke. It has a .89 Bore/Stroke ratio. A 6/1 Lister/Listeroid has a .818 Bore/Stroke ratio.

With greater low speed torque capability from the increased mechanical advantage from the crankshaft and never going over 75% of the maximum engine capability, enables the Witte to use a "mechanical governor" and still provide engine speed control similar to an electronic governor controlled engine. 

The disadvantage of the old style "over squared" engine design is that the power strokes are very intense compared to a shorter stroke engine and this is nullified by those massive flywheels.

The hybrid AC/DC inverters/batter bank is a "vital" part of my design. It allows me to "retard" the pump timing between 2 - 3 degrees, due to the constant load from the 28 volt alternator to eliminate carbon build up. The retarded timing drastically increases engine life more than many realize. Especially at low speeds, reducing the sudden shock load to the piston, rod and mains.

My hybrid configuration operates similar to a Series Hybrid propulsion system, which the engine stays at a constant speed and provides a small AC output and a small DC output and the inverters and battery bank carries the heavy loads. Permitting the engine to be tuned for a constant low steady output, years if necessary that other configurations can't claim. The continuous output could be as high as 8,400 watts when needed at times and will only consume about 3 gallons in a 24 hour period at 438 RPM.

When a conventional engine/alternator design is required to have the capability to produce "clean" (not over loaded blowing black smoke) AC at 8,400 watts constant, it would consume maybe twice that fuel. So this design is not for everyone but I designed it solely to meet my exact needs and in this advanced hybrid mode, my 1951 Witte is the best prime mover for this application.

I built my system with only three set requirements, Durability - Durability - Durability at the lowest fuel rate possible.

Diesel Guy

[LowGear]

Aloha Diesel Guy,

Thanks for the philosophical overview. 

I checked the bore 4.25 and stroke 6.00 on my Witte BD.  Its pretty out of square too.  4.25 / 6 = .71  Not quite the .625 the CD totes but still a pretty strong indication of torque potential.  The Old Man, it's a place of respect in some families, would shutter at my choice as he felt square engines was where it was at.

My plan is to get either a three phase or 400 hz alternator and rectify it into DC for my grid-tie inverter.  Pretty constant load.  The nice thing about the three phase is that, I think anyway, it can produce standard single phase juice if really needed.

My engine is rated for 900 RPM but has a very sweet spot at about 700.  Of course this could change with the addition of load but the "Old Man" taught me to run machinery at about 75% of its maximum ability as you mentioned.  OK it does take longer to mow the field but I expect repairs to be half as frequent.  Set on my butt playing Darth Vader with the vegetation and rocks or spend money and time screwing around with pressed steel machinery.  This is an easy decision for me.

I'm still looking for "Generators for Dummies".  I taught computer skills for many years and usually enjoyed these "Dummies" booklets and always learned from them.  I also was fascinated about what was not in them. 

Casey