Under/Overvoltage relay

Diz
15 ●5 ●6 ●8

Hi Everyone, I am trying to implement Over/Under voltage relay at a bus. The only relay model I can see is VTGDCAT/VTGTPAT in miscellaneous other models but the problem with these model is the breaker time should be same for upper and lower voltage threshold. My question is how to write a python code so that we can have different breaker time for different upper and lower threshold voltage as below ?

V (pu) = 1.1, 1.05, 0.9, 0.7 time(s)= 1, 5, 3, 2
and so on...

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@yfing, Thanks for you quick response. When you say each bus do you mean adding three more fictitious buses ? I recall we cannot add same relay more than one in same bus.

Diz (Mar 7 '14)

You can have same relay being used more than once for the same bus. The value of MINS (below on my answers) has to be unique.

jconto (Mar 7 '14)

@jconto, Appreciate your response, that helped.

Diz (Mar 10 '14)

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answered Mar 7 '14

yfwing
436 ●2 ●3 ●8

In your case, I would use four VTGDCAT/VTGTPAT models for each bus. The first two relays are for over voltage relay (i.e., the VL can be set at a very low value). The last two relays are for under voltage relay (i.e., the VU can be set at a very high value). For your particular example, it could be

Model 1: VU = 1.1, VL = 0.2, TP = 1.0, TB = 0.0

Model 2: VU = 1.05, VL = 0.2, TP = 5.0, TB = 0.0

Model 3: VU = 1.5, VL = 0.9, TP = 3.0, TB = 0.0

Model 4: VU = 1.5, VL = 0.7, TP = 2.0, TB = 0.0

TB is an arbitrary number that I put there. You can change it based on your real value.

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Please mention the data for under frequency relay. Thanks in advance

gajendra (Apr 3 '19)

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answered Mar 7 '14

jconto
2766 ●10 ●30 ●41

You can have different breaker values. The trick is to separate the UV relay definition from the OV by using more than one relay record. The example below is for a VRT relay schema.

/MINS model     M     M+1 M+2  VL   VU    TP    TB  /
1     'VTGTPAT' XXXX  xxx xx   -1   1.3   0.034 0.1 /
2     'VTGTPAT' XXXX  xxx xx   -1   1.2   0.5   0.1 / 
3     'VTGTPAT' XXXX  xxx xx   -1   1.1   5     0.1 / 
4     'VTGTPAT' XXXX  xxx xx  0.1   5     0.15  0.12 / 
5     'VTGTPAT' XXXX  xxx xx  0.9   5     3     0.12 /

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Under/Overvoltage relay

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