Date Code 20010625
Loss-of-Potential, CCVT Transient Detection,
4-1
Load-Encroachment, and Directional Element Logic
SEL-311L Instruction Manual
SECTION 4: LOSS-OF-POTENTIAL, CCVT TRANSIENT
DETECTION, LOAD-ENCROACHMENT, AND
DIRECTIONAL ELEMENT LOGIC
I
NTRODUCTION
The SEL-311L Relay provides loss-of-potential (LOP) detection, CCVT transient detection, load
encroachment detection, and voltage-polarized directional and distance elements when voltages
are connected to terminals VA, VB, and VC. Distance element operation is described in
Section 3: Line Current Differential, Distance, Out-of-Step, Overcurrent, Voltage, and
Synchronism Check Elements
. This section describes the LOP, CCVT, and load-encroachment
logic, and also describes the operation of current and voltage polarized directional elements.
When voltages are not applied to the relay, or when an LOP condition exists, current polarized
directional elements are still available. The voltage-polarized directional elements and distance
elements are disabled. Overcurrent elements controlled by voltage-polarized directional elements
are either disabled, or become nondirectional based on setting ELOP as described below.
L
OSS
-
OF
-P
OTENTIAL
L
OGIC
The loss-of-potential (LOP) logic operates as shown in Figure 4.1.
Figure 4.1: Loss-of-Potential Logic
Summary of Contents for SEL-311L
Page 6: ......
Page 8: ......
Page 26: ......
Page 54: ......
Page 144: ......
Page 216: ......
Page 252: ......
Page 302: ......
Page 338: ......
Page 480: ......
Page 484: ......
Page 486: ......
Page 502: ......
Page 532: ...12 28 Standard Event Reports and SER Date Code 20010625 SEL 311L Instruction Manual 4 ...
Page 552: ......
Page 554: ......
Page 574: ......
Page 576: ......
Page 596: ......
Page 602: ......
Page 628: ......
Page 656: ......
Page 662: ......
Page 664: ......
Page 688: ......
Page 700: ......
Page 716: ......
Page 722: ......
Page 734: ......