Diffrential Protection Relay

G

Thread Starter

gillani

we have 15 MW steam Turbo alternator at 5.5 kV, and at Bus bar 02 Nos. step-down transformers of 8000 KVA each at 5500/3300 V. when we switch ON one of transformer then Generator tripped of Differential protection (BASLER model BE1-CDS 220)with following data:

IA 512 A < 0
IB 306 A < 81
IC 651 A < 208
IN 4.7 A < 2
IQ 206 A

how can we avoid from this issue?

regards,
Ali
 
Ali, this will acknowledge receipt of your SLD. Following are several questions:

1) Do the current-values cited represent the Basler Relay's current-measurement upon switching on the 5.5kV CB of one 8MVA Xfmr to the 5.5kV, with its 3.3kV CB open?

2) Do the current-values cited represent the Basler Relay's current-measurement upon switching on the 3.3kV CB of one 8MVA Xfmr while its 5.5kV CB is closed?

3) Are the 6MVA, 11/3.3kV, Xfmrs connected to an 11kV source?

Regards,
Phil
 
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