GE Multilin
B90 Low Impedance Bus Differential System
5-3
5 SETTINGS
5.1 OVERVIEW
5
5.1.2 INTRODUCTION TO ELEMENTS
In the design of UR relays, the term
element
is used to describe a feature that is based around a comparator. The compar-
ator is provided with an input (or set of inputs) that is tested against a programmed setting (or group of settings) to deter-
mine if the input is within the defined range that will set the output to logic 1, also referred to as
setting the flag
. A single
comparator may make multiple tests and provide multiple outputs; for example, the time overcurrent comparator sets a
pickup flag when the current input is above the setting and sets an operate flag when the input current has been at a level
above the pickup setting for the time specified by the time-current curve settings. All comparators use analog actual values
as the input.
The exception to the above rule are the digital elements, which use logic states as inputs.
Elements are arranged into two classes,
grouped
and
control
. Each element classed as a grouped element is provided with
six alternate sets of settings, in setting groups numbered 1 through 6. The performance of a grouped element is defined by
the setting group that is active at a given time. The performance of a control element is independent of the selected active
setting group.
The main characteristics of an element are shown on the element logic diagram. This includes the inputs, settings, fixed
logic, and the output operands generated (abbreviations used on scheme logic diagrams are defined in Appendix F).
Some settings are specified in per-unit (pu) calculated quantities:
pu quantity
= (actual quantity) / (base quantity)
Where the current source is from a single CT, the
base quantity
is the nominal secondary or primary current of the CT. Use
the secondary current base to convert per-unit current settings to/from a secondary current value, and use the primary cur-
rent base to convert to/from a primary current value.
REMOTE OUTPUTS
DNA BIT PAIRS
REMOTE OUTPUTS
UserSt BIT PAIRS
RESETTING
DIRECT INPUTS
DIRECT OUTPUTS
IEC 61850
GOOSE ANALOGS
IEC 61850
GOOSE UINTEGERS
SETTINGS
TESTING
TEST MODE
FUNCTION: Disabled
TEST MODE FORCING:
On
FORCE CONTACT
INPUTS
FORCE CONTACT
OUTPUTS
NOTE
Summary of Contents for B90
Page 10: ...x B90 Low Impedance Bus Differential System GE Multilin TABLE OF CONTENTS ...
Page 284: ...5 166 B90 Low Impedance Bus Differential System GE Multilin 5 8 TESTING 5 SETTINGS 5 ...
Page 334: ...10 8 B90 Low Impedance Bus Differential System GE Multilin 10 2 BATTERIES 10 MAINTENANCE 10 ...
Page 338: ...A 4 B90 Low Impedance Bus Differential System GE Multilin A 1 PARAMETER LISTS APPENDIX A A ...
Page 460: ...C 30 B90 Low Impedance Bus Differential System GE Multilin C 7 LOGICAL NODES APPENDIX C C ...
Page 476: ...E 10 B90 Low Impedance Bus Differential System GE Multilin E 1 IEC 60870 5 104 APPENDIX E E ...
Page 502: ...viii B90 Low Impedance Bus Differential System GE Multilin INDEX ...