Auto-Recloser Check Mode - NR Electric PCS-9611 Instruction Manual

operated successfully.
The auto-reclosing startup logic diagram is shown in Figure 3.17-3. To prevent the auto-reclosing
startup element from undesired operation, this relay takes the currents into account (the signal
[79.OnLoad]). Only when the circuit breaker has tripped completely, the auto-recloser will be put
into service.

3.17.4 Auto-recloser Check Mode

Three check modes are adopted in this relay: synchronism check mode, dead check mode and
non-check mode. Each mode can be selected through a corresponding logic setting.

Synchronism check mode
The following conditions must be satisfied in the synchro check auto-reclosing function.
1. The protection voltage is greater than the setting [25.U_Lv];
2. The synchro-check voltage is greater than [25.U_Lv] / [25.U_Comp];
3. The voltage difference between the protection voltage and the synchro-check voltage
(ΔU = |U - U
Prot
4. The frequency of protection voltage and the frequency of synchro -check voltage are in
the range f
n
5. The frequency difference between the protection voltage and the synchro-check voltage
(Δf = |f - f
Prot Sy n
6. The phase angle difference between the protection voltage and the synchro-check
voltage (Δδ = |Φ
For the details about the settings [25.U_Comp] and [25.phi_Comp], see Section 7.4.1.
If the above conditions are satisfied at the same time for longer than [25A.t_SynChk], the
signal of the synchronism check of the auto-recloser "25A.Ok_SynChk" is issued.
When the reclosing operation is executed, this relay checks the synchronism check closing
conditions in the period of the setting [25A.t_Wait]. If the synchro check closing conditions are
satisfied, this relay will issue the reclosing command.
The logic diagram of the synchronism check element for the auto-recloser is shown as below.
U
Prot
U
Syn
ΔU < [25A.U_Diff]
Δf < [25A.f_Diff]
Δδ < [25A.phi_Diff]
Figure 3.17-5 Logic diagram of the synchr onism check element for AR
Where:
"U " is the protection voltage value;
Prot
PCS-9611 Feeder Relay
× [25.U_Comp]|) is less than the setting [25A.U_Diff];
Sy n
± 5Hz (f : the rated system frequency);
n
|) is less than the setting [25A.f_Diff];
– (Φ
+ [25.phi_Comp])|) is less than the setting [25A.phi_Diff].
Prot Sy n
> [25.U_Lv]
> [25.U_Lv]/[25.U_Comp]
Date: 2014-04-08
t 0
&
ARSynChk
3 Operation Theory
25A.Ok_SynChk
3-59