Section 4
1MAC050144-MB C
Protection functions
130
615 series ANSI
Technical Manual
4.1.3.2
Function block
Figure 53:
Function block
4.1.3.3
Functionality
The three-phase overcurrent protection 67/51P and 67/50P is used as one-phase,
two-phase or three-phase directional overcurrent and short-circuit protection for feeders.
67/51P and 67/50P picks up when the value of the current exceeds the set limit and
directional criterion is fulfilled. The trip time characteristics for low stage 67/51P and
67/50P-1 and high stage 67/50P-2 can be selected to be either definite time (DT) or inverse
definite minimum time (IDMT).
In the DT mode, the function trips after a predefined trip time and resets when the fault
current disappears. The IDMT mode provides current-dependent timer characteristics.
The function contains a blocking functionality. It is possible to block function outputs,
timers or the function itself, if desired.
4.1.3.4
Operation principle
The function can be enabled and disabled with the
Operation
setting. The corresponding
parameter values are Enable and Disable.
The operation of directional overcurrent protection can be described using a module
diagram. All the blocks in the diagram are explained in the next sections.
67/51P
I_B
I_A
PICKUP
TRIP
I
2
I_C
V_B_BC
V_A_AB
V_C_CA
BLOCK
ENA_MULT
67/50P-2
I_B
I_A
PICKUP
TRIP
I
2
I_C
V_B_BC
V_A_AB
V_C_CA
BLOCK
ENA_MULT
1
V
2
V
1
V
2
V
67/50P-1
I_B
I_A
PICKUP
TRIP
I
2
I_C
V_B_BC
V_A_AB
V_C_CA
BLOCK
ENA_MULT
1
V
2
V
Содержание 615 Series ANSI
Страница 1: ...Relion Protection and Control 615 series ANSI Technical Manual ...
Страница 2: ......
Страница 29: ...1MAC050144 MB C Section 615 series ANSI 22 Technical Manual ...
Страница 389: ...Section 4 1MAC050144 MB C Protection functions 382 615 series ANSI Technical Manual ...
Страница 485: ...Section 6 1MAC050144 MB C Supervision functions 478 615 series ANSI Technical Manual ...
Страница 635: ...Section 10 1MAC050144 MB C Other functions 628 615 series ANSI Technical Manual ...
Страница 707: ...Section 15 1MAC050144 MB C Applicable standards and regulations 700 615 series ANSI Technical Manual ...
Страница 711: ...Section 16 1MAC050144 MB C Glossary 704 615 series ANSI Technical Manual ...
Страница 712: ......