ERL L-PRO 4000, Руководство пользователя

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4 Protection Functions and Specifications
D02706R02.30 L-PRO 4000 User Manual 4-23
25/27/59 Sync
Check
The relay can bring in voltages from both line and bus PTs. The Line Sync
Check function, if enabled, looks at the voltage steady state angle between the
line and bus PT voltage. If this angle is within a plus/minus specified value, (+/
- 1 to 50 degree magnitude range of setting available), the function enables a
definite time delay pickup (user-selectable 0 to 10 seconds) after which time
an output is produced.
The line sync reference voltage is taken from a bus source. The relay can bring
one single phase-to-neutral voltage. Logic within the relay allows the single-
phase quantity to be either A, B or C phase. All unused single-phase inputs
must be grounded for proper operation.
The Dead Main Live Auxiliary (DMLA), Live Main Dead Auxiliary (LMDA)
and Dead Main Dead Auxiliary (DMDA) logic functions use fixed values of
main and auxiliary positive sequence secondary voltages to determine the Sync
Check condition. The voltage is fixed at 20 V secondary, voltages below 20 V
are declared a dead state and voltages above 20 V are declared a live state.
When enabled, this function checks that the voltage angle between the line PT
and bus PT are within a specified value. Use this function to ensure that closing
a line to a system will result in acceptable power flow. The function uses pos-
itive sequence voltage, and therefore, can accommodate single-phase sources
as well as 3-phase sources. If a single-phase source is used, it must be connect-
ed to the corresponding phase designation on the relay input. For example: If
only a B-phase bus PT is available, it should be connected to the relay input B-
phase terminals. In this example, the voltage and angle limit is 20 degrees with
no pickup or drop out delay.
The Dead Main Live Auxiliary, Live Main Dead Auxiliary and Dead Main
Dead Auxiliary logic functions use fixed values of main and auxiliary positive
sequence secondary voltages to determine the sync check condition. The volt-
age is fixed at 20 V secondary. Voltages below 20 V are declared a dead state
and voltages above 20 V are declared a live state.
Table 4.9: 25/27/59 Sync Check Settings
25 Sync Check Enable/Disable
Maximum Voltage 60.0 to 138.0 V secondary
Minimum Voltage 40.0 to 69.9 V secondary
Angle Difference 1.0 to 50.0 degrees
Pickup Delay 0.00 to 10.00 seconds
Main/Aux
Enable Dead Main Live Aux. (DMLA) Enable/Disable
Enable Live Main Dead Aux. (LMDA) Enable/Disable
Enable Dead Main Dead Aux. (DMDA) Enable/Disable