Synchronizer Unit 1

[ccdubs]

Hi,

I am after a synchronising relay that will operate when frequency, voltage and phase angle are in specified tolerances. A function to set contactor closure time would be useful too.

I do not need a synchronizer as voltage and frequency are already controlled, all I want is a unit to switch when in a defined synch window.

I have looked at synch check relays but they all seem to have very low resolution windows.

I am having great difficulty finding a unit and any help would be appreciated.

Cheers

 

[jbartos]

Suggestion: Visit

http://www.thomasregister.com

and enter Relays: Synchronizing under Product and Service, which will return 8 companies to contact for synchronizing relays. Another ones are on web only:

http://www.beckwithelectric.com/syncro.htm

etc.

 

[peterb]

What ranges are you after? What do you define as a low resolution window?
I note that the Alstom KAVS relay has the following settings available -
- Undervoltage detector range 22-132 V, step 0.5 V
- Diferential voltage range 0.5-22 V, step 0.5 V
- Phase angle range 5-90 deg, step 1 deg
- Slip frequency range 0.001-2.000 Hz, step 0.001 Hz
- Slip timer 0.1-99 sec, step 0.1 sec

All of the above indicate the possibility of setting a very narrow synchronizing window, particularly if you are confirming synchronism rather than trying to actually synchronize across a breaker.
If you are looking for a device that sets the contactor closure time, then it sounds as though what you need is really a synchronizer after all.

In addition to Beckwith, check the Basler website.

 

[ccdubs]

I have been given a window of:

+/- 0.1Hz
+/- 0.1Hz/s
+/- 10deg
+/- 3% Voltage

So your relay would be adequate and I will research it.

The main problem is the old one of cost. I am tending to find relays that are in our price bracket that are just outside of tolerance. The relays I find in tolerance are way outside our price bracket. With no inbetween.

I am a recent graduate and learning all the time. I am finding that the above scenario is not uncommon and seems to be the norm. Although I am in a country with little experience in the industry I am in.

As we do not need the relay to control f and V, I don't think I am looking for a synchronizer. But this device will be the initiator of contact closure to connect our generator with the grid.

 

[jwerthman]

All of the following have what you need:

http://www.beckwithelectric.com

http://www.basler.com

http://www.ch.cutler-hammer.com

 

[peterb]

ccdubs -
One important philosophical difference here -
A SYNCHROCHECK relay verifies that two systems are already in synch, then closes a permissive contact to allow the breaker to be closed.
A SYNCHRONIZER adjusts the speed and voltage as required, then issues the closing command to the breaker, advanced by the appropriate time to allow for the breaker closing time.

If you plan to use the relay as a check on synchronism, then you need to wire the contact in series with the breaker control switch - the synchrocheck relay shouldn't be used to initiate the breaker closing on its own. I have used the Alstom relay extensively, and this accepts a breaker close control switch contact - in this instance, the synchcheck output contact closes the breaker directly, but it has already been conditioned by the relay internal logic to react when the closing control switch initiates closure, providing the systems are in synch.

As regards cost, depends on what you are after. There are devices available at relatively low cost, such as would be appropriate for small gensets (for example, do a search for Crompton Instruments; Basler also has a line of lower cost devices), while larger generators would normally be equipped with "utility grade" devices - this is what the others and I were talking about above.