Lister Engine Forum

Lister Engines => Listeroid Engines => Topic started by: Michael on September 15, 2007, 08:40:18 PM

Title: Lister Generator Systems - What Are My Options?
Post by: Michael on September 15, 2007, 08:40:18 PM
With the new EPA rules, it looks like I am a day late getting into this hobby (funny hiow that always happens to me with the smog regs).  I have only found one company selling Lister Generator systems, Central Maine Diesel.  Are there others I should be looking at, too?  I'm open to doing assembly, but I don't have the time for heavy fabrication.

Also, I have sensitive computer equipment I'll be running.  I've seen the ST waveforms on this site, and they will not do (too much distortion).  Another problem one person here mentioned was on his system that the low rpm powerstrokes will actually flicker the lights.  From a power output per dollar standpoint, I'd rather stay with an alternator, but is it possible to get good quality A/C power from a Lister system, or should I just go straight to a Lister driving a DC generator to an inverter system?  I don't want waste time and money going down a dead end.

Thanks for the advice!

Michael
Title: Re: Lister Generator Systems - What Are My Options?
Post by: wrightkiller on September 16, 2007, 01:09:30 AM
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Title: Re: Lister Generator Systems - What Are My Options?
Post by: BruceM on September 16, 2007, 05:28:47 AM
I think you'll get better help if you can tell us what your likely planned loads will be.

It's true that there is both voltage frequency and amplitude modulation at 5.5Hz from a 650 rpm 6/1 Listeroid driving an ST generator (ST5 is the best match for this size engine) on the standard harmonic winding excitation.  This is not a  problem for most induction motors, or for most switching power supplies and battery chargers.

Equipment which has frequency sensing and is fussy about that will not be happy, and I think that is likely in many UPS units.

WIth an external electronic regulator on an ST generator head, the harmonic winding distortion is eliminated and the AC waveform looks quite good, and Both Bill R and Jeff M have measured below 4% THD with external regulation.  External regulation also eliminates most of the 5.5Hz voltage variation by my testing but the frequency variation remains. (The regulator holds the voltage quite steady but the engine still has a half sine wave like, 5.5 Hz rotational velocity variation from the power stroke (increase speed) to the next compression stroke (decrease speed). This will show up as a slight 5.5 Hz frequency modulation of the 60Hz power cycle. (Starting just a bit below 60Hz, then increasing rapidly after the power stroke, topping out at 6X.X Hz , then falling below 60 Hz during the next compression stroke.)

I suspect that with an external regulator, more people could tolerate Listeroid incandescent lighting, but as I have epilepsy and am flicker sensitive, I do not.  Many people (men more than women) seem to not mind or notice the stock harmonic winding ST 5.5Hz flicker at all.

The power stroke/ power frequency variation issue will be a problem with any generator head on a Listeroid. Geno is doing some voltage testing with his SOM flywheeled Listeroid but I haven't come up with a circuit for frequency variation measurement yet.

I don't have any experience with the high current output  DC alternators but I'm sure someone who does can give you some advice. 

Best Wishes,
Bruce M
Metro 6/1 running a 5HP Eaton 2 stage air compressor and an ST3 with both harmonic and external regulator (modified Jeff M design)
Snowflake, AZ








Title: Re: Lister Generator Systems - What Are My Options?
Post by: Michael on September 16, 2007, 06:35:49 AM
That is some very interesting information regarding the 5.5Hz frequency variation and voltage fluctuation.  Now that I think about it, every piston engine driven generator would have this problem to some extent, but for slow speed engines, such as the Lister, it is excerbated by the step up ratio to the alternator, and the low cylinder count (fewer power pulses per revolution).

My computer equipment load is approximately 2kW including laser printer.  The UPS systems would probably have a problem with the frequency variation.  They are rated for 57 to 63 Hz.  The on-battery trigger may be sensitive to rate of change as well as magnitude.  My other loads include a 1.65kW microwave oven (I've heard those can be sensitive to power quality), a 600 watt refrigerator, and probably a 3-ton A/C unit (the latter two not particularly sensitive other than needing high starting current).

I appreciate the help!

Michael

Title: Re: Lister Generator Systems - What Are My Options?
Post by: LowGear on September 16, 2007, 11:10:41 PM
How sure are you that your computer equipment is that voltage / frequency choosie?

LG
Title: Re: Lister Generator Systems - What Are My Options?
Post by: aqmxv on September 19, 2007, 06:16:38 PM
Keep in mind that there's no magic in a UPS either.  You can build your own double-conversion UPS out of deep-cycle batteries, an inverter large enough to handle the load, and a battery charger rated for enough continuous output to power the maximum continuous load.  Battery chargers tend to be completely uninterested in the dirtiness of the electricity that powers them.

Further, if you later get a native DC power source (solar or wind), you can easily hook it up to the battery through a charge controller...
Title: Re: Lister Generator Systems - What Are My Options?
Post by: gpkull on September 20, 2007, 01:03:09 AM
if you have a lister or a riod varying 5 hz it is either over loaded or the governor is lazy. bruce you have a problem if thats what your 6/1 is doing. this is a problem that you will correct or you will pay. motors are not as forgiving as you state. frequency (HZ) is rpm only the smoke gennie will prove this. a good governor wont cheat the public and should maintain +/- 1 hz from unloaded to fully untill overload then all bets are off. the voltage is controlled by regulation of volts to the field windings. the st head is as crude as they get. the power that has been produced from them for 50 or so years has not changed. the design was not meant to power any electronics as they did not exsist. two sides here power to survive and fix ez or trying to run a computer or watt ever during a hurricane and hope your lying sales person will help you out when needed most
Title: Re: Lister Generator Systems - What Are My Options?
Post by: cujet on September 20, 2007, 02:59:47 AM
Like you, I need to run all sorts of equipment via the Listeroid. This is mostly due to power outages after hurricanes, but also when I feel like running off grid. As a person with an aeronautical engineering background and a capable fabricator, I did my best to achieve a quality system. I fell quite short of the ultimate goal of smooth power, but I still have some tricks to try.

At a glance: Bluprinted and balanced 20/2 Listeroid with extra heavy flywheels and internal crankshaft counterweights, 15KW ST head and extra heavy pully assy. 

My neighbor has a standard 16/2 with a 10KW ST head. He had some significant flicker issues. This is why I chose to double the flywheel inertia and add a much heavier pulley on the gen head. What I ended up with is belt "chirp" as the pulley inertia is enough to resist the engine's power stroke, in addition to just slightly less annoying flicker.

Not one of my UPS's is fully happy with the Listeroid power. Some will accept the Listeroid/ST power only when a significant load is applied to the ST head, such as running the 5 ton central air. Some of the UPS' will not accept the power at all, even when adjusted to the "least sensitive" setting. The microwave groans too. Plus, the Listeroid governor is not up to the task of accurate frequency control. The best I have seen is about 1.5 HZ from 25% to 75% load. Maybe 2.5 HZ min to max. Freq self damping becomes a problem with closer control. The Listeroid Gov is not designed with good RPM control in mind, with a spec of 6%.

However, the engine will run well on anything I feed it, it will start the 5 ton AC without any problem, is fairly thrifty on fuel and will run all day without attention. It also starts right up without any problems.

My current plan is to install an additional 100 pound large diameter gen head flywheel to further reduce the power stroke induced flicker. I also plan on installing a capacitor on the Z winding to smooth out the nasty sine wave a bit. Will this fix all the issues? In my case, it is likely to get me close to what I need.

By the way, my 11 HP portable 5500 watt generator has no issues with the UPS' and does not display much flicker. Also other people point out that a 3600RPM gen head produces even more flicker related problems when used on a Listeroid.

I hope this helps you decide.

Would I do it again? Probably not. I would choose at least a 3 cylinder diesel running at 1800RPM coupled with a modern gen head. A neighbor purchased a 30KW Mitsubishi 4 cyl quiet diesel genset for 9K. I have seen smaller units, fully enclosed with fuel tank for 5K AND they come with a 5000 hour warranty!

Did I enjoy the project? Yes! I like to build stuff.

Am I happy with what I ended up with? Yes! It sure looks nice (fancy paint job) and it is fun.

How long do I expect the engine to last? 5000 hours between overhauls, based on the visible wear rate.

Does it serve my needs? Yes, for the most part.


Chris

Title: Re: Lister Generator Systems - What Are My Options?
Post by: BruceM on September 20, 2007, 03:07:11 AM
gpkull- You misunderstood.

The nominal 60 Hz output is varying slightly in frequency, faster and slower.  This modulation of the AC frequency is happening at the  5 Hz power stroke/compression stroke frequency.  I did not say that the frequency was varying by 5 Hz.

I don't know the amount of frequency change at the 5 Hz modulation rate, it would take some clever circuitry to measure that.  I would make a WAG at 1%, way less than 1 Hz.  But it's only a WAG.

Most modern switching power supplies are extremely tolerant of frequency and voltage variations.  It's only UPS's that are monitoring the incoming power frequency that are problematic. 

I agree that the ST heads are crude and simple.

Bruce M
Title: Re: Lister Generator Systems - What Are My Options?
Post by: gpkull on September 20, 2007, 03:58:52 AM
sorry if i read you wrong bruce. i still say that the st has proven true, dirt cheap, and ez to fix.   in fla the power goes out whenever. during hurricane outage we be lookin for the basics.  the city gives out ice after 9 days and the outage could go for 15. i have had gas "scream,ers" the power is good and clean but the gal/hr will eat a new assh--e also in daytona the pumps are down when the winds blow. the listeriod/st head combo cant be beat if you ask me. flickerin lights are better than no lights. one will adapt when needed to . jut my 2 pennys
Title: Re: Lister Generator Systems - What Are My Options?
Post by: cujet on September 20, 2007, 12:15:42 PM
Michael,

If I ever get around to it, I will add a 2000+ watt Full Sine Wave inverter and charger and a small battery bank on critical house circuits. This solves nearly all of the problems. In my case specific circuits in the breaker box would be simple to re-wire to a full time inverter/charger. Problem is that I would be powering more of the house via inverter than desired due to house wiring. It would eliminate the UPS' all over the house (I have 6). 2 computers, 2 DTV, 1 security sys, 1 security video.

I found a 2400W Xantrex inverter/charger on Ebay that also functions as a UPS with 30msec switchover. What could be cooler that that! Wonder if it could be configured to function as a UPS or full time like an inverter running off of batteries with a separate charger?

By the way, the computers run just fine on the ST power, just the UPS' give me problems.

Chris
Title: Re: Lister Generator Systems - What Are My Options?
Post by: ronmar on September 20, 2007, 07:43:24 PM
I found that adding capacitor filtration to the rectifyer output(removing the ripple) made the ST's AC output way more friendly to my UPS's that I have to test with.  I posted about it, with links to the o-scope pics I took, in the "ST power useless" thread down in the Generator forum. http://listerengine.com/smf/index.php?topic=1699.0  I put my testing on hold for other projects this sumer, and am working on getting the generator into it's new hut this week, so hopefully I will be able to post with what I finally come up with and it's results soon.

Ron 
Title: Re: Lister Generator Systems - What Are My Options?
Post by: BruceM on September 20, 2007, 11:01:22 PM
Ron, I'm baffled abot your success with a cap across the rectified harmonic output.  Both Bill Rogers and I have messed with that and had no change in the waveshape.  His is an ST12, mine is an ST3.

After a lot of experimenting and head scratching, it was concluded that it was the inductive impact of the harmonic winding current directly on the ouput winding (they're wound together) that was causing the problem in the single phase ST heads.  The 3 phase don't have this distortion.

Diode noise is way too fast a phenomina to cause the dips in the waveform.  So something else is going on.  Also the "flat topping" of the waveform you mention  is not typical... o'scope screen shots by Bill R, Jeff M, and myself don't show that. So something is unusual about your ST5.  I know you're   highly competent and you got the results you did, but I wanted to let you know that it isn't consistent with other's work I also respect or my own. 

I hope Bill will comment but I don't know if he reads here anymore.

Edit-  Sorry Ron, after reviewing the screen shots of your o'scope, I see that you did have an unusual high frequency distortion caused by your harmonic, and your capacitance did do the trick on that, though the harmonic "hump" was still present.  The "flat topping" you see is also high frequency, and is a bit more than normal but still is typical ST peak distortion caused by the winding placement.  And of course you're right that some passive filtering of the output (LC) would reduce that greatly. Sorry about the confusion on my part.

Bruce M

Title: Re: Lister Generator Systems - What Are My Options?
Post by: ronmar on September 21, 2007, 12:38:30 AM
Yep, definite differances in consistency amoung the ST heads.  Diode noise is fast, but the timing is right when compared to the output waveform.  I think more than noise was that it was probably the pulsed nature of the unfiltered rectifyer output which coincides with the diode switch points.  I know it sure cleaned up the spikes on the ascending and descending portion of the output AC sinewave as seen in the scope shots.  It did not completely remove them though and even exciting with pure DC from batteries, they is still something there on the o-scope which indicated to me something in the winding/construction of the generator, or an interaction with the harmonic winding.  This is of course a little outside my normal specialty, so some of this is educated guessing:)

The trip-lite UPS did require a little load on the generator to startup, but once it accepted the AC, it stayed on line regardless of load changes.  The small APC I have is also happy with the ST output using filtered excitation.  Those are the only two models I have among the 3 UPS's I use around the house to use for testing.       

I am not sure how much filtration on the rectifyer output I will ultimately settle with as I am trying to do away with the doghouse so space down in the main case is at a premium.  I think I will probably have to switch the doghouse to a more rigid NEMA enclosure as the cap configuration I last tried and worked the best(5200uF/300MV ripple) is the equivelent size of 5 "D" cell batteries. I also need room and heat dissipation capacity for the resistors to limit the current out of the "Z" winding to get the voltage back down in spec.

Ron
Title: Re: Lister Generator Systems - What Are My Options?
Post by: Ironworks on September 21, 2007, 01:02:35 AM
With the new EPA rules, it looks like I am a day late getting into this hobby (funny hiow that always happens to me with the smog regs).  I have only found one company selling Lister Generator systems, Central Maine Diesel.  Are there others I should be looking at, too?  I'm open to doing assembly, but I don't have the time for heavy fabrication.

Also, I have sensitive computer equipment I'll be running.  I've seen the ST waveforms on this site, and they will not do (too much distortion).  Another problem one person here mentioned was on his system that the low rpm powerstrokes will actually flicker the lights.  From a power output per dollar standpoint, I'd rather stay with an alternator, but is it possible to get good quality A/C power from a Lister system, or should I just go straight to a Lister driving a DC generator to an inverter system?  I don't want waste time and money going down a dead end.

Thanks for the advice!

Michael

Man these things are all over Ebay.  Take your pick.
Title: Re: Lister Generator Systems - What Are My Options?
Post by: Doug on September 21, 2007, 02:34:41 PM
Ron, I'm baffled abot your success with a cap across the rectified harmonic output.  Both Bill Rogers and I have messed with that and had no change in the waveshape.  His is an ST12, mine is an ST3.


Diode noise is way too fast a phenomina to cause the dips in the waveform.  So something else is going on.  Also the "flat topping" of the waveform you mention  is not typical... o'scope screen shots by Bill R, Jeff M, and myself don't show that. So something is unusual about your ST5.  I know you're   highly competent and you got the results you did, but I wanted to let you know that it isn't consistent with other's work I also respect or my own. 

I hope Bill will comment but I don't know if he reads here anymore.

Edit-  Sorry Ron, after reviewing the screen shots of your o'scope, I see that you did have an unusual high frequency distortion caused by your harmonic, and your capacitance did do the trick on that, though the harmonic "hump" was still present.  The "flat topping" you see is also high frequency, and is a bit more than normal but still is typical ST peak distortion caused by the winding placement.  And of course you're right that some passive filtering of the output (LC) would reduce that greatly. Sorry about the confusion on my part.

Bruce M



Flat topping sounds like saturation, once you push above 100,000 lines per inch of flux the wave form starst to distort and this is typical of what it would look like.....
Reduce the excitation ( I know this will reduce the voltage ) and just look to see if it cleans up. If you get a sine wave back then that would confirm saturation. Next question is why?
Title: Re: Lister Generator Systems - What Are My Options?
Post by: ronmar on September 21, 2007, 05:58:57 PM
It wasn't so much a flat top as another frequency ringing across the peak of the sine wave.  I have to look back thru my pics, but I may have been at a higher than normal output voltage at that point and not reducing the excitation as much as I could to compensate for the increase the caps gave me.  I don't have a large variety of resistors of that capacity to combine so I was taking what was adequate to accomplish my testing.  Excitation might also explained why it wasn't consistent from cycle to cycle which would go along with excitation induced, if a particular harmonic winding was outputting a little greater when stroked by the rotating magnetic field.  It could also be that one diode set flows a little better than the other.

Ron 
Title: Re: Lister Generator Systems - What Are My Options?
Post by: Doug on September 21, 2007, 06:01:18 PM
Odd harmonics will make the kleading and trailing edge of the wave steeper as well as flatten the top.

Saturation will simply flatten the top....