Governor plc issue

[Shamas javeed]

Dear all
I have a Plc of Mitsubishi in speed governor of small hydel unit
The problem is it works only in grid mood (sinks only with already energised line from other station e:g only when the bus pt is energized)

How ever when I switch off the grid line and want to run it over isolation mood the governor goes on shutdown due to low frequency issue

What may be the possible issue with this device??
Regards

 

[ViCH]

You do not have any replays, maybe need to add some more useful info? What is the spec of generator? What is the load on the line and busbar during sync? How it share the load? Did you try move load to generator, before switching off the grid?

Viktor
Electrical Technician II

 

[Hoxton]

Please give some more details of your small hydro (?) set. Remember that 50 MW can be small to some users!

It sounds like your set needs commissioning, it does not seem to be changing between 'mains parallel' and 'island mode' correctly. This may be because of governor settings or something else.

I am concerned that you seem to be controlling this with a 'plc'

A plc is an empty shell until it is programmed! There can be a fair bit of design in programming this from scratch.

The are generator controllers on the market which will perform the function you are looking for. European manufacturers include DEIF and COMAP, there are many others worldwide. We all have our favorites.

It may not be too late to change to one of these - see if there is a distributor in your country who could help you sort this problem out.

So more details please so we can help you.

 

[thebard3]

If I interpret your issue correctly, you are using a discrete output to start a machine?
1- Make sure you are using the correct output type, whether sinking or sourcing and of the appropriate voltage.
2- Depending on the PLC, you may need to add a pull-down or pull-up resistor as appropriate to the output to ensure that the output voltage is always at the level intended. This can be an issue with high impedance loads.

Brad Waybright

It's all okay as long as it's okay.

 

[redlinej]

Two possible reason for this could be the hydro unit can only be operated in baseload or the unit can not carry the load by itself. it is too small.

Regards,
JS.

 

[electrageek]

Many small Hydro units are induction generators and and not designed to run Isolated from the grid. Give us the nameplate data on your Generator.