How is differential protection calculated?
Application Example on Transformer Differential Protection Calculation
- E87 = Y.
- W1CT = Y.
- W2CT = Y.
- CTR1 = 80.
- CTR2 = 240.
- MVA = 33.
- ICOM = Y.
- W1CTC = 0.
What is percentage differential protection?
Percentage restrained differential relays measure the individual branch currents and quantify the through current in the zone of protection. The percentage restraint characteristic requires that the differential current be greater than a percentage of the through (restraint) current.
Why do we use slope in differential protection?
The slope characteristic provides high sensitivity when low levels of current are flowing in the zone of protection but has less sensitivity when high levels of current are flowing and false differential current due to current transformer (CT) saturation is more likely.
What are the drawbacks of differential protection?
When differential relaying is used for protection, the CTs at both sides of the generator winding must be of equal accuracy. Otherwise if the CT errors are excessive it will cause the mal-operation of the relay.
Which relay is used in transformer?
Relays for Transformer Protection
|SL||Voltage Ratio and Capacity of Transformer||Common Relays|
|9||400/220KV 315MVA||Differential Relay Overflux Relay Buchholz Relay OLTC Buchholz Relay PRV Relay OT Trip Relay WT Trip Relay Over Load (Alarm) Relay|
What is line differential protection?
An alternative principle for line protection that is quickly becoming the norm is differential protection. Differential protection is based on Kirchhoff’s laws, stating that all current into a network node shall add up to 0 in an ideal system.
What causes a transformer to trip?
Home » What causes the breaker to trip on a low-voltage landscape lighting transformer? Breaker tripping can be caused by a number of factors due to excessive amp draw. … Primary causes of breaker tripping include poor wiring connections, improper wire sizing, too many lights on a run, and wrong transformer tap.