PLC Koyo direct 205

Hi im Ronald, I've been working on the wind power industry and we purchased these new PLC for our windmills. Its a Koyo Direct 250, and the problem with these PLC they have alot of problems. Sometimes they trip and they will say that its ONLINE but the turbine is offline...

what we do is that after like a day of run time, and when we come back to check the status of it, they are either down or it will state the wrong status of the turbine, and we do to make it work again, we reset the power of the whole PLC and then when we turn it back on again, it will work again properly (for the time being) and the error will be gone, and it will run for 2 days or so, then it will go back to the error again.

my question is... is there anyway we can fix these problems in these plc? or what cause it? we are puzzled about this problem?

I can't tell from your description whether you have a problem with hardware or with your application program. Unless someone already knows the details of your application, there is absolutely nothing in your description that provides any insight what might be happening.

Sometimes they trip and they will say that its ONLINE but the turbine is offline

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What do you mean by "they trip"? Does the PLC stop running? Who says "its ONLINE"? How do "they" tell you "its ONLINE"? What does "the turbine is offline" mean? Is there a sensor that tells the PLC that the turbine is offline?

Someone here may be able to help you diagnose your problem, but you need to do a better job of communicating what's wrong. Forgive me for stating the obvious, but if you are the person who wrote the program controlling the wind turbine, I hope you're more fluent in ladder logic than you are in English.

Hello,
I would think from what you have said is that your PLC has stopped. Well for whatever reason a PLC stops may sometimes be related to one of several things,
More information is required

ronpittc,

Are you powering your PLC from the windmill? If so the PLC can stop running due to low voltage, however when the voltage comes back up to spec. the PLC wont start executing without a full power cycle.

If this is the case you may want to go to a DC base that can be powered from 12-24vdc power supply, and use a battery backup.

You need to provide more information to be sure. We use DL205 almost exclusively and find them to be very stable; but we have stable power supplies..

Mike

more information

I'm sorry about the vogue description about the question that I had. I know I didnt really gave the details but anyway.


I work in wind turbines and to explain how the turbine works...
The wind turbines as we all know they need enough wind to start, in this case the turbines are automatic, they have instruments (which are connected to the PLC) that senses the wind speed and the direction of it. And after sometime if it senses enough windspeed to run it will go ONLINE (which appears in the monitor of the control panel)and the propellers will start spinning.

Stages of Wind turbines before they start which appears in the monitor of the monitor for the PLC.

1. Run Mode - means it starting up
2. Tracking Mode - sensing and testing itself if there is enough windspeed to start
3. Blade Roll mOde - slowly testing the propelers and break releasing
4. ONLINE - Doing its job.... full spin it produces power (brakes full release).

OFFLINE (which is the status of the turbine,which means it is not doing its job to spin because there is not enough wind to spin to generate power.

and here is our problem.

After a good windy day, after the turbines worked. I myself check the status of the wind turbines( if there is anything wrong both for the system and electrical. And from the outside I can tell that there is not enough wind to start, so im expecting to see in the PLC monitor status (it should indicate that it is in OFFLINE mode). But the thing is , it indicates or shows that the turbine is in ONLINE, RUN MODE, Blade ROLL MODE wherein the wind turbine is not moving or spinning at all and the brakes for the propellers are not retracted too.

So what we do to solve this problem, we try to turn off the power of the PLC and the control panel (which is the one controlling the automation of the turbine) and wait for 15 sec. and turn back the power ON. In this manner the PLC starts to initialized the condition of the wind turbine and shows the right status of the windmill and begins to do tracking mode and the incorrect reading is gone. (and also the break release is activated- which indicates the windmill is running well.)

This happens everyday , so i have to reset the power everyday just to make it run.

Our problem is we dont know what causes this error and it appears everday. is there a solution to it?

It's going to be tough to 'guess' what might be the problem. How does the PLC determine the current state of the turbine? Are you monitoring turbine output? If so, are you doing it with discrete inputs? Analog inputs? Serially? Magically?... utoh

There are plenty of us here who speak Koyo quite fluently. Any chance you can zip the project files and post them? That will surely make it a LOT easier to figure out the problem... :nodi:

beerchug

-Eric

I think that your PLC faults because of noise, spikes or brownouts in the supply to the CPU.
Focus on power supply to the PLC, any noise generating devices (large contactors, coils, VFDs, ...), proper grounding.

If you can, determine at which time the PLC faults. Try to match the time with some event (shutdown of the windmill for example), then try to force that event and see if it triggers the CPU fault.

Does a Koyo have a CPU diagnostics that can tell more than just "Fault" ?
Can a Koyo go into fault if there is a math overflow, or other programming error ?

Hi ronpittc,
I agree with Eric, (one of our AD Masters) that it would help to see the program if you can send it along. I also feel that you will more than likely solve your problem by installing a UPS unit on the PLC power supply line...I have quite a few AD 205 (250, 260)racks in the field right now, most running off of gensets, and have found that using a UPS to power the rack resolves 99% of call-backs. We now consider it SOP to include one in every panel we build.
Please keep us posted with how you are making out...feedback here helps us all!
David

Ronald,

Do you have the software to be able to monitor the ladder program in the PLC? Is the PLC still running when you have this problem?

If the problem is caused by the PLC dropping out of run mode, your task is to figure out why it stops running. This could be caused by problems in the program or by external factors like power quality.

If the PLC is still running the program, then cycling power puts everything back to an ititial state from which the turbine can restart gracefully. In this case, the flaw could be in the ladder logic or it could be due to a sensor not getting enough power to be able to indicate its true state or any number of other factors.

In either case, connecting to the PLC with DirectSoft can give you the information you need to figure out what's happening.

Have you talked to the person who designed the control system or the person who wrote the program?

Tough to say for sure, but I agree with the guys indicating power supply problems. We have had very few problems with the 250 PLC over the years, and most have either been power problems or analog input burnout, generally from voltage transients.

1) I suspect you have an inverter on the windmill, which may mean a lot of harmonics. Put a good transient suppressor with a filter on the AC power.

2) Make sure you have good grounding.

3) If you can go to DC power, do so, and make sure you have battery backup, transient absorption on the DC, and a power supply with a lot of ride through capability.

4) I'm not a big UPS fan, but it may help you in this case. Make sure you have a full time UPS with filtering and transient protection, not a dime store cheapy.

You never did identify if the PLC power is coming from the utility, from the turbine, or switched between them. It might matter.

I think Jesper, David, and Tom are right on. With ANY plc power quality is a big issue. Like Tom said, use a quality TVSS (Transient Voltage Surege Suppressor) and either a UPS or DC powered bases with a large reserve capacity power supply and it will solve most of the problems.

QUESTIONS:

1) You did not answer my previous question regarding the power supply, Hence all the responses going back to this issue.
What is your power supply to the PLC? Is it the turbine? It is well known that lack of power supply stability will cause the problems that your are refering to. If the power supply voltage drops below a certain point, the CPU run light may stay on, but the program execution may stop, or lock up etc...

2) Did you do a power budget on the PLC and the components in the PLC base? This is essential. You must add up all the power demands required from each module and make sure that the total demand is within the 205 base spec. This information can be found in the DL205 manual. Click on this Link , and search for the word "BUDGET".

Ron started two new threads with the same question, so I directed everyone over here. Ron's most recent question was:

Hi again, Im back with the same question... people here in PLCS told me its the power supply issue, i'm kinda uncertain about the answer because, the PLC has a separated power supply and it does not rely on the Wind Turbine. "we use AC and DC electricity separately to power our control panel, PLC and other peripherals, with that all those peripherals functioning it allows the turbine to operate and to create power going to the substation.

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Ron, please try to keep this in the same thread. Use the "REPLY" button.

beerchug

-Eric

Ron,

Did you calculate a "power budget" on the base, and modules? Check the link provided on my last post. If you base power supply will cannot support all the modules you will experience the problems you are indicating.

Mike.

Ronald,

It is not at all clear whether you have connected a computer running DirectSoft software to your PLC. You said that what you have been doing to get out the situation is to turn off the power to the PLC and turn it back on again. The state of the ladder logic in the PLC is a powerful diagnostic tool. Do you have this software and do you know how to use it?

On the PLC's CPU module are several LEDs. One of them is labeled "RUN". When it is lit, the PLC is executing it's ladder logic program. Is this LED lit?

With all due respect, if you don't know how to use the programming software, then you are probably not the person who is going to get to the bottom of this problem. If this is the case, call in a local integrator or technician with experience with this model of PLC and use this as an opportunity to learn. Your knowledge of the the wind turbine is supposed to work, coupled with the technician's knowledge of the PLC will be a combination that can solve the problem quickly.