Flywheel UPS, 500 - 1000KVA

[apa6eightball]

Has anyone had experiance with industrial sized flywheel UPS systems? My company is plauged by service line spikes, brown outs, blinks and storm related outages. I understand storm related outages but our power company is unable to correct or explain the brown outs and blinks which raise hell with our many 3 phase hydraulic power supplies. We use several 10 to 15 KVA battery based UPS for our electronics but I need to keep the 3 phase 480Vac up long enough to absorb the blinks or for the generator to switch on in an outage. I've just started to research this subject and found that EATON has a 750KVA flywheel system so there must be others.
Thanks in advance to anyone able to share knowledge on this subject

 

[itsmoked]

Where are you that this is common? Have you asked your neighbors if they have the same issue? Maybe it's just your facility which may mean you have a specific problem.

There is a company that is noted for flywheel storage generators. Not Eaton.. The name escapes me.. Someone will remember.

Keith Cress
Flamin Systems, Inc.-

http://www.flaminsystems.com

 

[umrpwr]

The two major manufacturers of rotary UPS are Piller and Hitec. They are both European companies. Their UPS designs are different, but they both manufacture large rotary UPS systems.

 

[davidbeach]

CAT also has a line of rotary UPS systems.

 

[ScottyUK]

The design offered by CAT and, I think, Merlin-Gerin uses a flywheel in a vacuum chamber as the energy store. I suspect the Eaton design is of this type too although I haven't yet found it on the net. Power conversion uses power electronics. Big advantage is they do not use batteries, big disadvantage is the very short run time for these units. They have most of the limitations of a static type except obviously battery maintenance. A static system has the option to provide extended runtime if you increase the battery size. This is harder to do with this type of rotary UPS. A static or a flywheel + electronics type UPS will not react well to the motor loads for your hydraulics for the same reasons that they have poor fault-clearing ability.

The rotary designs from Piller, Eurodiesel and Hitec (ex-Holec) types are all based around a specialised rotating machine which provides the energy store coupled via clutch to a diesel engine. The smallest of these units is about 250kW and they go up to about 6MW or so, maybe a little larger. These have good fault-clearing capability and motor starting capacity. This type is popular with the major financial institutions in The City where they are typically deployed in an N+1 redundant arrangement.

My opinion, based on what little I know of your application, would be to look at the rotary + engine types mentioned in my second paragraph for your application.

Where are you located? You need to look at support from the manufacturer or their agents: the best UPS in the world is useless if you have a problem and your nearest support is on another continent.


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I don't have an attitude problem. You have a perception problem...

 

[catserveng]

Try this link,

http://www.activepower.com/

This is the company that makes the CAT UPS systems.

Based on your description, this is likely a good solution from our experience.

 

[ScottyUK]

The spec sheet (900kVA 60Hz) is cute. Total omission of acceptable crest factor and no mention of overload / fault clearing capability when the utility bypass is not available!

Only the guilty have something to hide!!


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I don't have an attitude problem. You have a perception problem...

 

[apa6eightball]

WOW!!! Thanks everybody!! I have lots to digest along with my own research.
I live and work in Western PA and he have had power problems since the 90's when I started here. Our most common problem is when we lose power for just 5 - 10 milli-Seconds, our pumps shut off. This can happen in a storm, a calm sunny day and even the middle of the night. Once we had a squirrel fry while stretching from one power line to the next.
I found this paper from the US Dept. of Energy that everyone should find interesting

http://www.eere.energy.gov/femp/

it gives example applications and pro / cons of flywheels. Thanks again everyone!!!

 

[jupitar]

Correct me if i am wrong, you said you are having problem with your three phase hydraulic supplies....and if it is true, are they fed through contactors? and again if it is true, then the option of the rotary UPS becomes to expensive and what you need would be to correct a quality of supply to the contactor coils e.g by supplying the coils with power from a cheap standalone ups.

 

[ScottyUK]

I don't get the impression that controlgear is the big problem. Keeping a hydraulic pump running for the period between mains fail and the generator spinning up is the real trick. Finding a UPS which will absorb a motor start while on internal power is even trickier. That's where the non-electronic types (Piller, Eurodiesel, Holec, etc) have benefits.


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Sometimes I wake up Grumpy.
Other times I just let her sleep!

 

[apa6eightball]

You are right ScottyUK, we used to try keeping some of the contactors up with a battery UPS and succeded in burning up motors when the voltage dipped or a single phase dropped out on the mains, I'm telling you the quality of our power leaves much to be desired.
We run high performance servo hydraulic actuators with these pumps and it doesn't take much of a motor RPM drop to affect the hydraulic pressure even with accumulators on the pressure line.

Thanks again everyone for your input!!

 

[ePOWEReng]

5-10 milli-seconds is a VERY short amount of time to be causing problems. Could you go into more details about why the problem is sensitive to that short of a voltage dip? How did you come to the conclusion that the source of your problem was a 5-10 milli-second loss of power? I think their should be a solution to make your load less sensitive if this really is the case.

 

[ruggedscot]

You could maybe rent an ION based moitoring system and check out your supples and see where you are dipping....

Rugged

 

[ScottyUK]

I agree with hold6448, that is remarkably sensitive for a hydraulic system. Do you know if the fault originates in the hydraulic system or is it being adversely affected by an upset in the electronics? Instinctively I am guessing the electronics may be the real problem. To give some idea of what is going on out on the utility supply network, even the fast protection on the network takes about 1 mains cycle to operate - 20ms in Europe - although a few ultra fast types are capable of sub-cycle response. Transmission system protection is maybe 3 or 4 cycles with a reasonably modern breaker and relay. Network faults are an everyday occurrence and if this system is designed to run from the public supply it needs either protecting, which seems to be what you are doing, or re-designing to be less sensitive, which might be more cost-effective in the long run. Motor contactors should not respond noticeably to a 5-10ms drop-out, and the motors will likely have enough stored energy in the rotating mass to ride through such a small disturbance.

Does your system have a hydraulic accumulator local to each actuator? A remote accumulator isn't much help - short runs of full-size pipework right up to the actuator is ideal.


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Sometimes I wake up Grumpy.
Other times I just let her sleep!

 

[powersmp]

I know American Electric Power has a flywheel set up. Maybe contact someone with them and see what they spec'd it out to be.

 

[riessen]

You could consider the Ride Through system from Hitec Power Protection: flywheel, power quality compensation choke and synchronous generator in one package (the UPS system without a diesel engine).

http://www.hitecusa.com

or

http://www.hitecups.com

 

[apa6eightball]

OK, We have 60, 3000-PSI hydraulic power supplies in a remote room under our material testing lab (isolates noise and heat). They consist of 1 - 125 HP, 2 - 75 HP, 25 - 50 HP and the rest are 10 and 20 HP 480 VAC 3 phase motors and they power actuators rated from 2,000 to 1,000,000 pounds force. The piping runs from 25 to over 100 ft in length and all of the actuators have acumulators sized by the equipment mfg.
I'll admit that I could be mistaken about 5 -10 ms, Hold6448, but if you blink your eyes at the instant our power blinks you will miss it. It is just long enough for an office computer UPS to beep a short alarm or a hydraulic power supply to stop instantly, there is no ride through momentum that I've ever seen.
We've had beautiful weather since the middle of last week and our power blinked on the evenings of August the 30th, 31st, mornings of September 1st, 2nd and the 3rd causing all of the running hydraulic power supplies to shut off and the power company has no explanation for why it's happening.
I like what I read about the HiTec ride through system, riessen, to bad their USA HQ is in Texas.
Thanks again everyone for your valuable input...'8ball

 

[ScottyUK]

apa6eightball,

Big recommendation for the EuroDiesel and Pillar UPS designs. Not sure how well supported they are in the US.

When you say the hydraulic pump stops, do you mean the contactor drops out and the pump stops, or that the pump trips the overload or breaker as a result of abrupt deceleration and acceleration?

You might want to consider hiring a disturbance analyser and monitoring the mains supply. That way you will know what problem you are fighting, even if you don't know the cause, and from then we may be able to help a bit more or you may even be able to go back to your utility with a formal objection to the quality of supply. To do that you'll need hard facts about the problem which the disturbance analyser will help you obtain.



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Sometimes I wake up Grumpy.
Other times I just let her sleep!

 

[apa6eightball]

ScottyUK,
I'm saying that the contactor drops open and the motor stops immeadiatly. I've never used a disturbance analyser, would you recommend a Mfg and model number?....'8ball

 

[itsmoked]

That really is exactly what you should do. Get a third party to monitor this problem and produce a report. This will certainly put the utility under the spotlight. The testing company is then an unbiased, disinterested party, to force the utility to seriously investigate, as this type and frequency of outages is not acceptable. Since it happens on a regular basis I bet they are causing it via a voltage regulator or a line switch or?? They may not even know there is a faulty piece of equipment in their system. A 'third party' axes the "whining customer" denial.

If you don't follow this course you are cruising for a severe bruising. Why? Because you could spend a million bucks for a solution only to have the power company fix the problem eventually anyway, or have the problem change character so your fix ceases to be a fix.

Keith Cress
Flamin Systems, Inc.-

http://www.flaminsystems.com