Section 11 Multipurpose protection
11.1 General current and voltage protection CVGAPC
IP14552-1 v2
11.1.1 Identification
M14886-2 v3
Function description IEC 61850
identification
IEC 60617
identification
ANSI/IEEE C37.2
device number
General current and voltage
protection
CVGAPC 2(I>/U<) -
11.1.2 Functionality
M13083-3 v6
The protection module is recommended as a general backup protection with many possible
application areas due to its flexible measuring and setting facilities.
The built-in overcurrent protection feature has two settable current pickups. Both of them can be
used either with definite time or inverse time characteristic. The overcurrent protection steps can
be made directional with selectable voltage polarizing quantity. Additionally they can be voltage
and/or current controlled/restrained. 2nd harmonic restraining facility is available as well. At too
low polarizing voltage the overcurrent feature can be either blocked, made non directional or
ordered to use voltage memory in accordance with a parameter setting.
Additionally two overvoltage and two undervoltage steps, either with definite time or inverse time
characteristic, are available within each function.
The general function suits applications with underimpedance and voltage controlled overcurrent
solutions. The general function can also be utilized for generator transformer protection
applications where positive, negative or zero sequence components of current and voltage
quantities are typically required.
Additionally, generator applications such as loss of field, inadvertent energizing, stator or rotor
overload, circuit breaker head flash-over and open phase detection are just a few of possible
protection arrangements with these functions.
11.1.2.1 Inadvertent generator energization
SEMOD158308-4 v2
When the generator is taken out of service, and stand-still, there is a risk that the generator circuit
breaker flashes over or is closed by mistake.
To prevent damages on the generator or turbine, it is essential that high speed tripping is
provided in case of inadvertent energization of the generator. This tripping should be almost
instantaneous (< 100 ms).
1MRK 502 066-UUS B Section 11
Multipurpose protection
687
Technical manual
To Next Page
Loading...
