Lister Engine Forum

Lister Engines => Lister Based Generators => Topic started by: Gregmm on December 08, 2005, 01:26:12 PM

Title: External regulator V Governor as regulator
Post by: Gregmm on December 08, 2005, 01:26:12 PM
Hi all this is a great forum. I am an engine guy not an electric guy so this may be a dumb question. When a ST gen head hits 60 cycles and an extra a load is applied to the lister the governor try’s to compensate so you get a flux in the 60 cycles because the governor is a little primitive in response it can take a short time to compensate. Now I read Rocketboys mechanical fix and that would seem to work well but does some one make an exturnal regulater that would regulate, say 62 cycles down to 60 so I get no change at all. So I set the Lister to produce 62 cycles and the regulator keeps it at a constant 60 so when extra load is applied no change. I like the fact that the ST head does not have an internal regulator as it could go bad and then you are off line until you fix the head. With an external regulator if it failed you just disconnect it and you still have power using the governor to regulate. Buy the way I got my Lister from Joel and George @ Power Solutions Nice guys all the way around and George answered all my questions even the dumb ones. Thanks George and Joel

Greg.  ???
Title: Re: External regulator V Governor as regulator
Post by: rocket on December 08, 2005, 03:29:46 PM
i dont think your cycles changing  from 60 to 62 or down to 58 are going to be that critical. you will also find voltage swinging around alot. i have run generators that were even less precise than the lister with st head and had no problems. maybe the tv scrounges a little when the pump comes on or lights flicker. i would be interested in what some of the other guys have noticed if anything more. the most critical thing in my mind when running a genset is make sure its up to speed when you switch to it and up to speed when you switch from it, and up to speed all times during.. running out of fuel and it coming down while say your water pump is on is pretty hard on that sort of thing.
Title: Re: External regulator V Governor as regulator
Post by: quinnf on December 08, 2005, 04:08:31 PM
Greg,

I agree with my esteemed colleague that it's probably not really necessary to have the frequency spot-on.  However, if you want to, you could run a DC generator and an inverter which will give you better regulation on the output.  Overall efficiency will be less, but if you have some sort of critical load that can't handle the usual excursions of voltage and frequency that are common to locally generated power, that might work for you.
Title: Re: External regulator V Governor as regulator
Post by: cujet on December 09, 2005, 03:41:27 AM
There is no simple way to regulate freq's. Only voltage.

BTW, Rocketboys engine really does maintain frequency quite well. I may try to expand on the improvements he made by adding an actuator to keep the engine rock steady at 60HZ. Could be done easily with a PIC and small linear actuator.

Chris
Title: Re: External regulator V Governor as regulator
Post by: Gregmm on December 11, 2005, 12:46:55 AM
My thinking is I can get waste motor oil for free and I want to see how the Indian Lister will do on the 24/7 program. With normal oiling and such. I was considering importing a container or 2 and if it holds up I could see my self-doing it. As such why not sell back some of the power to the grid I was under the impression I need to be at a steady 60 cycles to do that. I am still checking into it but that was why the 60 cycle question.

Greg 
 ;D
Title: Re: External regulator V Governor as regulator
Post by: SHIPCHIEF on December 11, 2005, 06:17:49 AM
Although frequency variations from no load to full load may vary from 62 Hz to 58 Hz, and voltage from 250 to 220, your houshold really won't be effected. Even the best mechanical 'isochronous'  governors did this to a lesser extent. It's called speed droop, and is a governor adjustment for paralleling AC generators so they can share load. The only diesel governors I have seen that have no speed droop are electronic governors. Part of the fun of these LISTEROIDS is the do it your self add ons. If you cook up a good speed control governor out of cruise control car parts from your 'free collection' and share it on this list, we would all be amused and greatful.
Title: Re: External regulator V Governor as regulator
Post by: hotater on December 11, 2005, 06:37:42 AM
All right!  Cruise control for a governor.
     I read somewhere they work off a magnetic sensor on the driveshaft and are most accurate at about 60 mph. If the Lister is too slow to allow this to work right could EXTRA magnets be placed to fool the unit into thinking there's more rpms present? I'm betting they'd have to be spaced RIGHT to work!
Title: Re: External regulator V Governor as regulator
Post by: WWIProps on December 11, 2005, 02:40:43 PM
If you want to sell power back onto the grid use an induction motor run above its synchronous speed. 

I use a 5hp Weg ODP single phase induction motor as my generator.  I removed the start circuit , the start capacitor and run capacitor from the connections. The two wires hook into a magnetic starter relay, a 40 amp breaker in my panel and out to the utility grid.  If your grid power is three phase just get a three phase induction motor which is generally cheaper and does not have capacitors or start circuits.

The magnetic starter is so if the grid power dies, my generator shuts down and does not restart or try to send power to the grid on its own. 

For a backup generator system you could come up with capacitor banks to provide excitation when the grid is disconnected.  (Haven't tried that one yet)  Or just use a second small generator hooked up in parallel with your lister.

I run a 6/1 that I set at 21 amps (1800-1835 rpm George had the pulley made). Frequency and volts follow the utility.  My system is 230volts single phase so it produces 4.8kw at this setting.  The more the engine breaks in the more I have been able to produce.  I think the higher output I am producing than guys with stand alone generators do is because I get my kVars for excitation from the grid. 

Good luck!

Scott
Title: Re: External regulator V Governor as regulator
Post by: Gregmm on December 12, 2005, 01:03:14 PM
Thanks for the info that would be an option at this point I just want to test the Lister Clone To see how reliable they are and if I can sell power back that is an added bonus.

Greg :D
Title: Re: External regulator V Governor as regulator
Post by: Stan on December 18, 2005, 03:07:48 AM
Just a reply for those who think that "mains" power is accurately transmitted.  My son lives in an upscale neighbourhood, with lots of homes  bringing prices with 6 or more zeros in them. He has been complaining his natural gas heater fan seems to dip in rpms occasionally.  I was sitting in his living room yesterday when the neighbour started using his power saw.  Every time the saw came on, the heater fan dipped significantly in speed.  I figure the neighbourhood is over populated with high draw devices and underpopulated with transformer capacity???  Don't know how to document this but would like to.  Maybe something to watch the cycles???
Stan
Title: Re: External regulator V Governor as regulator
Post by: trigzy on December 18, 2005, 10:40:15 PM
Hello,
       I've been an observer on this forum for a little while now, thought I could interject with some electrical knowlegde.  I work for a power utility that provides electricity for over 30% of the Canadian population.  I can guarantee that you aren't experiencing a frequency drop-out.  All protections in stations are set to open breakers at 57-59Hz or 61-63Hz on the high-end.  On a utility scale, this frequency swing is considered massive, and causes equally massive voltage swings.  These type of protections are what kicked in and causes the large blackout in the North East US/Canada in Aug'03. 

But it definatley sounds like you have some voltage/power factor issues.  Frequency is the only thing that is constant between the supply (generators) and the load, and utility generators shut down outside of frequency limits.  On the issue of documenting voltage though, it's certainly not hard.  Our utility allows for voltage as low as 113, and as high as 127 (measured at the customers main breaker)  anything staying outside these limits for more than 30 seconds could be grounds for a compliant or corrective action.  A simple multimeter will give you some basic readings, let me know what they are and we can talk about different fixes.

Steve


Just a reply for those who think that "mains" power is accurately transmitted.  My son lives in an upscale neighbourhood, with lots of homes  bringing prices with 6 or more zeros in them. He has been complaining his natural gas heater fan seems to dip in rpms occasionally.  I was sitting in his living room yesterday when the neighbour started using his power saw.  Every time the saw came on, the heater fan dipped significantly in speed.  I figure the neighbourhood is over populated with high draw devices and underpopulated with transformer capacity???  Don't know how to document this but would like to.  Maybe something to watch the cycles???
Stan
Title: Re: External regulator V Governor as regulator
Post by: GerryH on December 27, 2005, 05:37:24 PM
Hi WWWprops,
Your on the right track, but consider using a 3 phase motor of the correct voltage and kw draw as a genset. You provide 60 cycle excitation to one coil and generate from the other coils. Reguardless of rpm, it will maintian 60 cycles. You can feed the exciter current to it from a battery powered inverter if you are off grid, to get the 60 cycles that way.
I have used this setup with a pelton wheel as attempting to govern rpm on a fluxuating water flow drove me nuts. Voltage regulation was a wire wound rotary resistor on the wall.(I know its crude) wired into the exciter line.

Gerry
Title: Re: External regulator V Governor as regulator
Post by: rpg52 on December 27, 2005, 07:16:46 PM
Hi Everyone,
You guys have a much more sophisticated understanding of electricity than I, so I won't try to add to this discussion.  Regarding mechanical governors however, I can add a bit (electronic governors are beyond my experience).  This info is from a 1950's Detroit Diesel Operator's Manual.  There are three basic types of mechanical governors.  All of them rely on spinning weights that adjust the fuel rack to try to maintain the engine speed within limits. 
The Limiting Speed Governor just limits the idle speed and maximum speed.  It has two sets of weights, one for high speed and one for low speed. They were used on trucks, etc. to maintain idle and prevent over-revving while allowing infinite control between for acceleration. 
The Variable Speed Governor was used on tractors, graders, etc.  I believe this is the type used on Listeroids.  It is purely mechanical and is designed to maintain a given set speed, and adjust that speed by adjusting the fuel rack when the rpm drops or increases.  As others have mentioned, it is not terrible sensitive to change, at least compared to the last one.
The Hydraulic Governor is (as its' name implies) dependant on oil pressure change to advance or retract the fuel rack, depending on rpm.  It is much more sensitive to "speed droop" than the others, and is preferred for applications where that affects performance, such as sawmills and generators.  It is also more complicated and precise, which is likely the reason it isn't found on Listeroids.
I would suppose that electronic governors are the best for limiting speed droop, but putting one on a Listeroid might be like adding a computer to a Model T - possible perhaps, but maybe beyond the purpose of its' existance?  Regarding checking the frequency and voltage of generated electricity, as many of you already know, the Killawatt is an extremely useful electronic method of checking how clean your power is.  I used it to set the frequency of my power and others have said it is likely more accurate than many meters, certainly the ones that come on the ST gen heads.
Ray
Title: Re: External regulator V Governor as regulator
Post by: WWIProps on December 27, 2005, 11:03:27 PM
Gerry,

I have single phase service at my house and am doing net metering with my local utility.  If I use a 2 phases of a 3 phase generator to run to the grid won't I have a problem?

Thanks,
Scott
Title: Re: External regulator V Governor as regulator
Post by: trigzy on December 29, 2005, 03:50:15 AM
Scott,
     Short version of the story is yes.  Your 1 phase service is probably 120/240, and your 3 phase motor will be 120/208.  That means across any two phases, there is only 208V, so the output probably wont be high enough to sell back to the grid (motor speed, and individual motor will determine this though).

With any 3 phase motor you will run into an asyncronous loading problem if creating or using three phase power, because one coil isn't being used at all, so you will have a reduction in power (msg me if you'd like a more indepth or technical explanation on this)

Steve
Title: Re: External regulator V Governor as regulator
Post by: GerryH on December 29, 2005, 04:23:21 PM
Hi WW1Props,
Yes Trygzy is technically right. but voltage is also a product of rpm and the exciter wattage. you can increase voltage by increased rpm. You cannot generate 3 phase this way to my knowledge. You can get single phase and have it cycle in step with the line power providing excitation, and when the line power quits you will loose excitation and the gen will not be backfeeding your power company. Then, of course you will want to self excite it to see you thru the blackout and switch back to line excitation when the power comes back. Ooops, switched it early by mistake, did we?
My personal opinion is that it is not in the best interests of the lineman working on the line to be depending on your homegrown protection to not power up the line he thinks is dead. Unless the profit margin is real wild I would not try to sell or reverse the power meter unless I had wind or water power. The source of these may be free, but even then, the mainanence surel isn't.

Gerry
Title: Re: External regulator V Governor as regulator
Post by: WWIProps on December 30, 2005, 02:48:06 AM
Thanks Gerry,

My system is approved by the local utility.  No capacitors allowed or other excitation other than grid power.  The magnetic contactor prevents the backfeeding should the power fail.  The single phase motor works.  Unfortuantely I haven't found many single phase induction motors over 5hp so am interested in how to rig up a three phase unit to do what I am doing today.

I still have my old generator for off grid operation when the utility fails but am considering a really small unit for excitation.  I am still uncertain of how large a unit I need to meet the excitation requirements of my listeroid 6/1 3.7 kw.

I run with WVO on a combined heat and power system.  It is paying for itself quite nicely.  Maintenance may be an issue in the future but it keeps me out of trouble and my wife likes it because parts of the house are hotter than we would have kept them without this system.  Besides, its fun!

Thanks,
Scott
Title: Re: External regulator V Governor as regulator
Post by: Doug on January 08, 2006, 03:00:35 AM
Generating power with an Induction motor is called "Asyncronous generation".

Short list of comments based on what I've read:
You can use a 208 motor to generate single phase but the losses are higher than you would get with a capacitor run single phase and even that isn't as effcicient as something like an ST head (the brush kind are the only way to go in my opinion).

You can generate stand alone power with a Capacitor bank to provide the reactive power for feild excitation but because rotor currents are slip induced you have to drive the motor above its sync speed and monitor you frequency and voltage. This can be a real problem if you have a load change because now you have to change your motor speed to hold 60hz and adjust your capacitance to hold your voltage steady.

And you can even generate 3 phase if you like this way. In a grid connected system using two legs a three phase motor the third unused leg is actualy generating a third phase by induction you can use to start and run other three phase motors. Be warned the third leg of your new three phase system will be a little on the weak side don't expect it to start heavy loads like a 10hp compressor or run a welder.

Doug
Last but not least charged motor Capacitors can hold enough power to cause harm. I used to have a boss with whom I share a mutual hate. I used to charge caps on my test bench (to about 60 v) and leave them about the shop or stock room, and then ask him if he seen one because I need one and can't find any.

Heh heh heh!!!!
Title: Re: External regulator V Governor as regulator
Post by: Bansonyankee on January 15, 2006, 02:30:47 AM
With respect to speed governors, on my utility-parallel setup, it's not an issue since the utility controls the frequency.  All the governor does at that point is maintain the power output at the set point.  If the utility disconnects, then the speed governor "catches" the engine as it speeds up after being suddenly unloaded.

For the grid-independent folks, the mechanical governor on the Listeroids does an amazingly good job of speed regulation, considering how crude it is.  If someone needs dead-accurate frequency control, we can fix them up with an electronic governor.  These are made by Woodward, Governors America, and Synchro-Start.  There used to be another company, Barber-Colman, but they were bought by Woodward.  The system has three components, a speed sensor, throttle servo ("actuator") and the governor ("brain").  It'd require mounting a ring gear somewhere so there are gear teeth for the magnetic speed pickup to sense, but it could give very accurate speed control from zero to full load ("isochronous governing").  The cost for the whole setup would approach $1,000. 

Frankly, I doubt anyone on this forum really needs that level of accuracy on their frequency control.  Just don't run your alarm clock on the Listeroid. 

J.S.
Highland Power
Title: Re: External regulator V Governor as regulator
Post by: Procrustes on January 15, 2006, 08:24:51 AM
Thanks Gerry,

My system is approved by the local utility.  No capacitors allowed or other excitation other than grid power.  The magnetic contactor prevents the backfeeding should the power fail.  The single phase motor works.  Unfortuantely I haven't found many single phase induction motors over 5hp so am interested in how to rig up a three phase unit to do what I am doing today.

I still have my old generator for off grid operation when the utility fails but am considering a really small unit for excitation.  I am still uncertain of how large a unit I need to meet the excitation requirements of my listeroid 6/1 3.7 kw.

I run with WVO on a combined heat and power system.  It is paying for itself quite nicely.  Maintenance may be an issue in the future but it keeps me out of trouble and my wife likes it because parts of the house are hotter than we would have kept them without this system.  Besides, its fun!

Thanks,
Scott

Whoops, I didn't see this post until just now.  Thanks for answering these questions a second time.  I'm impressed with your setup!
Title: Re: External regulator V Governor as regulator
Post by: Procrustes on January 15, 2006, 08:32:32 AM
With respect to speed governors, on my utility-parallel setup, it's not an issue since the utility controls the frequency.  All the governor does at that point is maintain the power output at the set point.  If the utility disconnects, then the speed governor "catches" the engine as it speeds up after being suddenly unloaded.

For the grid-independent folks, the mechanical governor on the Listeroids does an amazingly good job of speed regulation, considering how crude it is.  If someone needs dead-accurate frequency control, we can fix them up with an electronic governor.  These are made by Woodward, Governors America, and Synchro-Start.  There used to be another company, Barber-Colman, but they were bought by Woodward.  The system has three components, a speed sensor, throttle servo ("actuator") and the governor ("brain").  It'd require mounting a ring gear somewhere so there are gear teeth for the magnetic speed pickup to sense, but it could give very accurate speed control from zero to full load ("isochronous governing").  The cost for the whole setup would approach $1,000. 

Frankly, I doubt anyone on this forum really needs that level of accuracy on their frequency control.  Just don't run your alarm clock on the Listeroid. 

J.S.
Highland Power

Here http://surplusman.com/P_GAC.php?menuid=20#Actuators is a page with some intriguing gear along these lines.

Incidentally, I'm amazed that you are setting up grid-tie in Massachusetts.  My time there was a prolonged cornholing: fines for not clearing the ice from the sidewalk in front of your house, getting your car towed for inscrutable reasons, getting permission to paint your front door, the DOL giving handicapped parking stickers to their buddies.  But there's much that I miss about it too.