Recloser control system

[johndaniel]

Hello guys,

I am working on distribution system where I have to develop a recloser control model in PSCAD. Although I have basic knowledge of recloser system but I couldnt find the control and operation of recloser system which I can emulate in PSCAD.

Any suggestions would be helpful to me.

 

[Mbrooke]

What company control are you using. IE, Cooper, SEL, GE...?

 

[johndaniel]

I am planning to use SEL relay.

 

[Mbrooke]

What are you trying to simulate exactly? Time current curves?

 

[johndaniel]

Yes I am having trouble in understanding time curves like what is it and how to simualte it. Could you please help me with it?

Thanks

 

[DTR2011]

Ist there a SEL 351 model available? Very Similar to 351R (Recloser)

 

[Mbrooke]

Time current curves are the easiest part of all this. I say easy because other elements of power systems are more complex.


Basically recloser controls come with a package of time current curves, IEEE inverese IEEE very inverse, IEC ect. Some models allow you to import your own. You then set a value of where the curves start to time along with time multipliers and adders to shift the curves from 'faster' to slower'. You can also add instantaneous/definite time elements where the recloser trips immediately on a high current values. Most of the time current curves that I work with are from Cooper, however for SEL they would be the same in terms of coordination. If the program doesn't have them specifically, you can always use IEEE, ANSI and IEC curves which are basic off the shelf standard curves.


This might be of help, its free. If you select recloser micro processor type in the scroll down menu for devices than click next to coordinate the new page will have a list of re closer controllers to choose from including SEL and then a list of tome current curves. You can then select values and graph them.

http://www.sandc.com/support/coordinaide/

 

[johndaniel]

Thanks Mbrooke the link was very helpful.
I have one question: In SEL relays what is the difference between SEL351R and SEL 551C model relays?

 

[Mbrooke]

To be honest I dont know, SEL relays aren't my relay of choice. Not that there is anything wrong with them (they are among the best) just not ones that I have modeled. You could E-mail SEL and ask for the difference, this might help also:

https://www.selinc.com/reclosercomparison/

Just out of curiosity, how are you modeling this, do you know the loads of the feeders?

 

[johndaniel]

@Mbrooke: I am using signal processing block to get the fundamental component of current and using the blocks for protection relay in PSCAD i will be designing control system. For the moment, I don't know the load of the feeders.

Sorry for the late reply.

 

[jghrist]

Equation for the various time-current characteristic curves (operating time as a function of time-dial setting and current as a multiple of pickup current) are usually in the manuals of microprocessor relays. The difference between an SEL-351R and an SEL-551C is that the 351R is specifically designed for automatic circuit recloser control and the 551C is a general purpose overcurrent relay. The SEL-351R will have traditional Cooper recloser curves as well as standard U.S. and IEC curves, but they won't have equations.

 

[Mbrooke]

Its ok


Is this just a single recloser, or several in series. Loop, mesh or radial? Any fuse saving or coordinating with cutouts?

 

[johndaniel]

Its multiple recloser in loop system. Although there are no fuse present in circuit but have to check how to do recloser-recloser coordination.

 

[Mbrooke]

Is this a simple loop? If so 3 or 5 reclosers? IE, Source-Tie-Source Or Source-Midpoint-Tie-Midpoint-Source?

 

[jghrist]

The Cooper Power Electrical Power Distribution Systems Protection Manual is a good source for recloser-recloser coordination. It can be ordered at

http://www.delzer.com/v5fmsnet/OeCa...unodseq=&FromFav=&PmSess1=1072&pos=CPSDLC&v=7

for $50.

 

[johndaniel]

@Mbrooke: It is a simple loop with 5 recloser.

 

[Mbrooke]

This might help. Its lengthy but toward the end goes into setting up a typical recloser loop scheme:

https://www.eiseverywhere.com/file_...9ad7076f9624d114_3_Cooper_Form6_S280_70_4.pdf

Page 3, 4 and 11 give a blurb about Loop schemes:

http://theline.cooperpower.com/assets/pdf/LINE-0898.pdf

 

[Mbrooke]

I left out that the first chunk of the first PDF goes into recloser to recloser coordination in a time current curve sense while the second part is loop schemes. I know I only mentioned looking at it toward the end but reading it over again all of it is very informative. You can test your time current curves in S&C coordinate if unsure.

 

[johndaniel]

@Mbrooke: This was really helpful. I appreciate your help and time on this.

 

[Mbrooke]

Welcome

These might help as well if looking for trip curves, at least the ones used on Cooper controllers:

https://www.eiseverywhere.com/file_...533bda0849d58140_3_4D_TimeCurves_R2809134.pdf

http://www05.abb.com/global/scot/sc...285256b4f005b06b0/$file/curve desgination.pdf

Really good one by S&C on loop restoration:

http://www.sandc.com/edocs_pdfs/EDOC_050252.pdf