Flexible Protection Functions; Functional Description - Siemens SIPROTEC 7SJ62 Manual

Functions

2.17 Flexible Protection Functions

2.17 Flexible Protection Functions
The flexible protection function is a general function applicable for a variety of protection principles depending
on its parameter settings. The user can create up to 20 flexible protection functions. Each function can be used
either as an autonomous protection function, as an additional protective element of an existing protection func-
tion or as a universal logic, e.g. for monitoring tasks.
2.17.1

Functional Description

General
The function is a combination of a standard protection logic and a characteristic (measured quantity or derived
quantity) that is adjustable via parameters. The characteristics listed in table 2-20 and the derived protection
functions are available.
Table 2-20 Possible Protection Functions
Characteristic Characteristic / Measured Quantity
Group
Current I RMS value of fundamental
component
True RMS (r.m.s. value)
I
rms
3I Zero sequence system
0
Positive sequence component
I1
I2 Negative sequence compo-
nent
Negative/positive sequence
I2/I1
component ratio
Frequency f Frequency
df/dt Frequency change
Voltage V RMS value of fundamental
component
V True RMS (r.m.s. value)
rms
3V Zero-sequence system
0
V Positive sequence component Voltage protection
1
V Negative sequence compo-
2
nent
Power P Active power
Q Reactive power
cos ϕ Power factor
Binary input – Binary input
Section 2.18 gives an application example of the function „reverse power protection".
The maximum 20 configurable protection functions operate independently of each other. The following descrip-
tion concerns one function; it can be applied accordingly to all other flexible functions. The logic diagram 2-106
illustrates the description.
284
Protective Function
Time overcurrent protection
Time overcurrent protection
Overload protection
Time overcurrent protection,
ground
Negative sequence protection 46
Frequency protection
Frequency change protection 81R
Voltage protection
Displacement voltage
Voltage protection
Displacement voltage
Displacement voltage
Voltage asymmetry
Reverse power protection
Power protection
Power protection
Power factor
External trip commands
C53000-G1140-C207-2, Release date 01.2008
ANSI No. Operating Mode
3-phase 1-phase
50, 50G X
50, 50G X
50N X
X
X
X
81U/O without phase
reference
27, 59, 59G X
27, 59, 59G X
59N X
27, 59 X
47 X
32R, 32, 37 X X
32 X
55 X
without phase refer-
ence
SIPROTEC, 7SJ62/64, Manual
X
X
X
X
X
X