Hydro turbine control

[Sidewinder]

Analogue IO is expensive!

So if you can avoid it then that is better.

Ahh, you are not in the UK are you!

Not sure what the requirements are over there, but, in the UK it would have to have an approved relay and depending on the power output that may have to be witness tested by the supplier.

 

[Rob.]

Analogue IO is expensive!

So if you can avoid it then that is better.

Ahh, you are not in the UK are you!

Not sure what the requirements are over there, but, in the UK it would have to have an approved relay and depending on the power output that may have to be witness tested by the supplier.

Still have to follow the EU regs. 

Most of the UKs have similar bearings.

 

[Grendel]

Analogue IO is expensive!

So if you can avoid it then that is better.

Ahh, you are not in the UK are you!

Not sure what the requirements are over there, but, in the UK it would have to have an approved relay and depending on the power output that may have to be witness tested by the supplier.

I take it you mean the price of the sensors.

Unfortunately, I think there is no way around them. I have been looking at 4-20 mA ultrasonic sensors for water level measurement.

First quote was 369 euros each. Found another company that sells them for 180 or so.

Still have to look into position sensors for the blade adjustment cylinder and the cylinder for adjusting the guide vanes.

Both are inside, so don't need to be water proof.

Any suggestions?

Hubert

 

[Grendel]

Another question: The runner blades are adjusted by a cylinder that is integral to the turbine shaft.

The rotary union is on top of the piston.

This is practical, but there is no way for me to know the position of the piston and/or the runner blades during operation.

I have a way to bring out an hydraulic piston rod through the lid to take position info from there, but I'd rather not if I don't have to.

Do sensors exist that can be screwed into the lid and take position of the piston through hydraulic oil?

A bit like an ultrasonic sensor? I hope they do, but I haven't been able to find them.

 

[Sidewinder]

I take it you mean the price of the sensors.

Unfortunately, I think there is no way around them. I have been looking at 4-20 mA ultrasonic sensors for water level measurement.

First quote was 369 euros each. Found another company that sells them for 180 or so.

Still have to look into position sensors for the blade adjustment cylinder and the cylinder for adjusting the guide vanes.

Both are inside, so don't need to be water proof.

Any suggestions?

Hubert

Also the IO cards for analogue are a lot more expensive than digital IO.

Then there is the faff of setting them up if you go 4-20, have you looked at bus type sensors, perhaps profibus, interbus, sercos or the like?

 

[Rob.]

What do you mean by faff of setting an AI up with a PLC? It's literally 2 minuets. 

Setting up telegrams for profibus etc is a lot more time consuming. Plus for maintenance, limits him in replacement options. 

 

[Grendel]

Besides that, I am not familiar with profibus and the likes.

To be honest, I have no idea how to go about this. Never heard of sercos.

If I knew what these were, I probably didn't need help.

I don't mean to sound unkind. I really apreciate any help I can get.

The reality is that I have never worked with these digital formats. I have worked as a ships engineer at sea and systems are usually traditional.

I like things easy, because in the end, I'll have to adjust the settings, tune and maintain the system myself.

 

[Sidewinder]

What do you mean by faff of setting an AI up with a PLC? It's literally 2 minuets. 

Setting up telegrams for profibus etc is a lot more time consuming. Plus for maintenance, limits him in replacement options. 

OK, fair comment, I'm more used to plug and play equipment on bus systems than I am on analogue 4-20 mA stuff.

We never had to set up telegrams, so I suppose it depends on which systems you are used to, ours were not geared around the 4-20 market.

 

[Rob.]

OK, fair comment, I'm more used to plug and play equipment on bus systems than I am on analogue 4-20 mA stuff.

We never had to set up telegrams, so I suppose it depends on which systems you are used to, ours were not geared around the 4-20 market.

The bus systems and data over comms are more accurate. 

However 4-20ma is far superior still. Easy to set up. Easy to maintain. Cheap. Include a HART signal imposed on top an you have everything you need. Doesn't suffer from volt drop. 

It only becomes less cost effective than comms when it is required to be safety rated.

 

[rapparee]

What do you mean by faff of setting an AI up with a PLC? It's literally 2 minuets. 

Setting up telegrams for profibus etc is a lot more time consuming. Plus for maintenance, limits him in replacement options. 

You can say that again

We were getting crucified with an old ASI system

We decided to rip it out and put in a traditional system.

 

[Grendel]

An update:

My AVR/Exciter has a can connection. It would be useful to be able to connect that to the plc.

It comes with a bunch of safety options and cos phy control.