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Discussion Starter · #1 · (Edited)
Hey guys, the hydroelectric power plant I work at has the hydraulics all jacked up. There have been a few leaks from the hydraulic pump to control the gates, and oil got into the kraut solenoid valves and whatnot, and things are all kinds of screwed up. Anyone know some good resources to read up on how this stuff works? The turbine and control system is all Ossberger, which is a German company (system in its current form was installed in 1985), and all the manuals we have are in German. There is also not a US distributor or parts supplier anymore, so we are basically on our own. I am weak when it comes to hydraulics and need to learn more about it, so any books, websites, what have you that you guys can point me towards would be greatly appreciated. Right now we are running on manual control with the backup hand pump, which is getting f*cking ridiculous. :laughing:

ETA: I am still going through the process of tracing out all the wiring in the control cabinet (the wiring diagrams we have might as well be used to start a campfire), so I will probably have a ton more questions as time goes on. Depending on how long we can keep the German system creeping along, I would like to work towards replacing it with new equipment run from a PLC, but that is down the road a ways.
 

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Discussion Starter · #2 ·
Wanted to add this picture to show you want I am dealing with. Babylon translator is getting a workout on my phone. :laughing:
 

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interesting stuff.

while you are figuring this stuff out, try to get your company to fork out for some trips to Packer's games, or maybe to Germany for Oktoberfest later in the year, under the guise of learning the language haha.

lets see some pics of the controls !
 

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Discussion Starter · #4 · (Edited)
interesting stuff.

while you are figuring this stuff out, try to get your company to fork out for some trips to Packer's games, or maybe to Germany for Oktoberfest later in the year, under the guise of learning the language haha.

lets see some pics of the controls !
That would be nice. Its owned by a municipality, so I don't see that happening. Here I am staying busy waiting for my boss to get parts.



ETA: took a bunch of pics but I'm on my phone. Will upload when I get home.
 

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the 2 biggest weaknesses with hydraulic control systems are leakage and air
cavitation in the hydraulic fluid caused by excessive turbulence can leave air bubbles in the high points in the system and decrease the efficiency of operation.
leakage usually caused by seals wearing out due to heat, contamination, and in some cases seal deterioration from using the wrong fluid type.

if the pressure is jacked up in the system then its either air or an attempt to make it run with the leaking conditions.
over pressure conditions can indeed cause leakage.

all in all hydraulic control systems are reliable and usually have a long life span.

in any event though you have a real mess on your hands to deal with
 

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I don't have any good resources. My MO was always to test all the electrical components in the system to be sure they were operating right, and after that, I could safely say "Yep, it's a hydraulic problem!" and you can often figure out where just by determining what limits aren't pulling in.
 

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Discussion Starter · #7 ·
I don't have any good resources. My MO was always to test all the electrical components in the system to be sure they were operating right, and after that, I could safely say "Yep, it's a hydraulic problem!" and you can often figure out where just by determining what limits aren't pulling in.
Should have taken pictures of the sludge that was packed into the filter. Apparently the boss man hasn't changed the filter in 8 years. System is probably looooooaaaded with sludge. :censored:
 

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Wish I could get my hands on it, been years since I worked electro-hydraulics. I spent 22 weeks @ 12 hours a day learning it for the navy back in 86.

Change the fluid, filter and flush it out.. Take your time drawing it out and you'll see how easy it is..

I'll look up a book left over from back then to get a company name for training.
 

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Big John said:
I've always said electricians were well suited to it. The schematics are similar to control diagrams. Think of pilot pressure as low-voltage.
Back then it was mostly Transistor logic for control of the gun mount. Funny how fast that equipment operated and it was more reliable then the new fangled digital controls that were out.

Control work boiled down to a simple concept, "Every control circuit component was on or off".
 

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Discussion Starter · #11 ·
Picasaurus-Rex:

Control cabinet outside:


Inside:





Hydraulic Pump Solenoid valves. Don't mind the rags. :whistling2:


 

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Discussion Starter · #12 ·
Generator Cabinet with protective relays:


Breaker to tie generator to grid:


Original generator setup, kept as spare parts for whatever reason, with a rotary exciter behind it:



Ossberger turbine. Horizontal setup, generator is a 600kW with a 1.5 service factor. Don't mind the mess, we just did annual maintenance a little while ago and still haven't cleaned everything up yet :laughing::

 

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Neat. Except for whenever I see those stupid square gauges I know troubleshooting likely just got to be that much more of a pain in the ass.

Just finished rebuilding one of those DB-15 breakers not long ago. I like Westinghouse a lot. Those plus the old GEs are workhorses if maintained.

What are you using the one Basler for?
 

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Discussion Starter · #14 ·
Neat. Except for whenever I see those stupid square gauges I know troubleshooting likely just got to be that much more of a pain in the ass.

Just finished rebuilding one of those DB-15 breakers not long ago. I like Westinghouse a lot. Those plus the old GEs are workhorses if maintained.

What are you using the one Basler for?
Honestly, I don't remember. I'd have to read the faceplate of it. :laughing:. I've only been in the plant like 4 or 5 days in the past 6 months. I was doing daily checks for a while, but now I am more of an extra hand, troubleshooter, that type of thing. I haven't done the day to day stuff since before I moved to California, so I am a bit rusty what all the protective relays and such do. I've got my work cut out for me now though, especially since getting this crap working again is going to be a spare time, nights and weekends gig. We also have to rebuild one side of the tailrace this summer, and a bunch of other work, so I am going to be one busy mofo at some point. I might be over there tomorrow, and if I am I will find out what the Basler is for. Reverse power maybe?

Funny thing about that breaker. A few years ago, a mouse made a nest in between the contacts when we were offline for the winter. That spring we got everything going, didn't check the breaker, and it went BANG when we hit the contact close button (manual sync). We ended up ordering all new contacts and such, rebuilt the breaker, and got it going again. Then, while we were doing some cleaning last summer, I asked the bossman what the wooden crate was for next to they hydraulics control cabinet. He said, "I've been here for 15 years, and I don't have a clue." Lo and behold, we pop the top off the crate and it is a brand new Westinghouse breaker. :laughing:
 

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What's the deal with someone manually opening and closing the wicket gates? Someone manned there all the time to adjust them for load changes? That must be inefficient. Then again, that's how they used to do it...

Wait handpump? Wouldn't your frequency on that machine be all over the show? Surely that couldn't be fast enough :S
 

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Discussion Starter · #19 ·
If he's feeding the grid then his frequency and voltage are fixed by the infinite bus. The governor just changes his power output.
Yup.

Basically, we base the output of the generator on the amount of river flow available. This plant is ~400 yards downstream from a lake, which has gates at the outlet, so we (in coordination with the state) set the out flow of the lake based on lake level and expected precipitation forcasts. Based on how much water is flowing out from the lake, we figure out how much we need spilling over the flashboards (plywood held in place by 1" schedule 40 pipes, will describe purpose later) at the dam (usually ~15-20 cubic feet/second) to keep the river level normal between the dam and the tail race (outlet) of the powerhouse. So, right now we are running at about 400kW, so that is roughly 100-120 cfs flowing through the turbines (iirc), with about another 20 or so cfs flowing over the dam (at lower river flows like now), which puts us at about 140-150 cfs going down the river. There are small streams and such that fill the river between the dam and the powerhouse, so aquatic life is not affected by generation, and to keep things looking pretty for the tourists.

At higher flows, say during spring runoff, where there is a much larger volume of water flowing into the lake, river flow will be greater. If I remember correctly, our plant at full power (rated 600kW, but we run about 680-700kW at full power due to service factor) will pull about 150 CFS of water through the turbine. I've seen 700 CFS flowing out of the lake, which means we have to open an additional waste gate, and drop the flashboards to allow a greater volume of water to flow over the dam without bypassing it (very very bad :laughing:). This is all a careful balancing act between keeping the lake from flooding the surrounding area, the plant making $$, and keeping the river flowing appropriately so wildlife isn't effected.

Flashboards (plywood held in place by pipes) are designed to raise the level of the pond to give the plant higher head. Head, in water terms, is the distance between the top of the mill pond to the turbine. This difference in height is what gives the hydraulic pressure necessary to spin the turbine and generate power. The head at this plant is 76' iirc, and the water flows from the dam to the turbine in 2 4' penstocks (pipes, basically). During normal operation the flashboards are in place at the top of the dam, giving us that extra bit of water pressure. During times of high flows, we pull the flashboards before increasing output from the lake, but sometimes there is just too much water pushing against them to remove them. When enough water is pressing against them, the 1" schedule 40 black iron pipes will fold over, the plywood will go down stream, and the dam will then allow a significantly higher volume of water flow over it without over-topping the embankments.

This is all a pretty slow process. River flow is usually pretty consistent except with heavy rains, spring run off, and fall draw down (lowering the lake level in preparation for winter to allow for more room for water in the spring). It's not like the river flow is changing by the minute. We have been at roughly the same river flow for the past month and a 1/2, but once the snow starts melting and flowing into the lake, the output will increase. When we have heavy, saturated, snow like we have now, a good portion of that will not be absorbed by the ground (considering the ground stays frozen longer than the snow), so it will flow into the lake and cause it to rise a few inches a day. Right now we are at about 8.9' of water at the staff gauge by the lake gates, but if we have a really wet spring compounded with the heavy snow, I have seen the lake get up about 13'. When times like that happen, we go WFO with the waste gate, turbine, an additional turbine to pump water to a storage tank, and drop the flashboards. Flows will be in excess of 650-700 CFS, and will flood the yards and such of houses down stream.

So basically Nuzzie, short story long, an operator only has to be at the plant to check it in the morning, do the daily calculations for power generation, revenue, greasing, etc, and once in the afternoon just to make sure everything is running OK. Extra time has to be spent over there changing river flow, maintenance, and if the plant gets kicked offline during a thunderstorm or whatever, but it's not like a guy has to stand there and tweak the power output all the time.

If you guys want to know more, just ask. What I don't know I can ask the boss man. Pretty cool side job, huh? :thumbup:
 

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If you guys want to know more, just ask. What I don't know I can ask the boss man. Pretty cool side job, huh? :thumbup:
Yeah definitely! What John was saying about power output. So, would you raise the voltage of your unit slightly higher than the grid but the grid is stiff enough that the grid voltage pretty much stays the same. Is that how it works?
 
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