GEK-113285A
G650 Generator Protection & Control System
5-51
5 SETTINGS
5.4 PROTECTION ELEMENTS
5
b) CURRENT POLARIZATION OPERATION PRINCIPLES:
Operation Magnitude:
In = calculated from phase currents.
Polarization Magnitude:
Ip, measured at input terminals B11-B12.
To perform a directional comparison by current, the polarization magnitude used is the current measured at the relay Ip
input, terminals B11-B12, with input or “positive” in B11. This current is taken from the source (transformer or generator)
neutral grounding.
Direction is considered to be forward when the phase shift between both magnitudes is lower than 85º. If the angle is higher
than 85º, the fault is considered to be reverse.
The following table shows the element’s output signals management (block and permission) depending on the polarization
type setting.
Table 5–46: OUTPUT SIGNALS MANAGEMENT ACCORDING TO THE POLARIZATION TYPE SETTING
Configuration of the required signals for blocking the neutral overcurrent elements from the signals provided by the neutral
directional elements is performed at
Setpoint > Relay Configuration > Protection Elements
using the inverted operation
signals to block the trip, as shown in the following example:
How to block neutral time overcurrent elements with neutral directional functions:
NEUTRAL TOC1 BLOCK = NOT (NEUTRAL DIR1 OP)
NEUTRAL TOC2 BLOCK = NOT (NEUTRAL DIR2 OP)
NEUTRAL TOC3 BLOCK = NOT (NEUTRAL DIR3 OP)
To block neutral instantaneous elements:
NEUTRAL IOC1 BLOCK = NOT (NEUTRAL DIR1 OP)
NEUTRAL IOC2 BLOCK = NOT (NEUTRAL DIR2 OP)
NEUTRAL IOC3 BLOCK = NOT (NEUTRAL DIR3 OP)
POLARIZATION SETTING
NEUTRAL DIR BLOCK SIGNAL
NEUTRAL DIR OP SIGNAL
Vo
Vo < POL V THRESHOLD setting
Permission Vo
Ip
Ip < 5 mA
Permission Ip
Vo + Ip
Vo < POL V THRESHOLD
Ip < 5 mA
Permission Vo
Permission Ip
Vo * Ip
Vo < POL V THRESHOLD
Ip < 5 mA
Permission Vo
Permission Ip
Summary of Contents for Multilin G650
Page 9: ...8 G650 Generator Protection Control System GEK 113285A TABLE OF CONTENTS ...
Page 426: ...GEK 113285A G650 Generator Protection Control System A 31 APPENDIX A A 1 LOGIC OPERANDS A ...
Page 427: ...A 32 G650 Generator Protection Control System GEK 113285A A 1 LOGIC OPERANDS APPENDIXA A ...
Page 587: ...C 22 G650 Generator Protection Control System GEK 113285A C 8 ANALOG INPUTS APPENDIXC C ...
Page 639: ...G 2 G650 Generator Protection Control System GEK 113285A G 1 GE MULTILIN WARRANTY APPENDIXG G ...